基础更新服务器，升级至 1.2.1 稳定版

admin/admin-page.php

@@ -9,13 +9,11 @@ $plugin = new WPNAV_Links();
 $success_message = '';
 $error_message = '';
 
-// Check if WPCY.COM plugin is active
 function wpnav_is_wp_china_yes_active() {
     if (!function_exists('is_plugin_active')) {
         include_once(ABSPATH . 'wp-admin/includes/plugin.php');
     }
 
-    // Check for common WPCY.COM plugin paths
     $possible_plugins = array(
         'wp-china-yes/wp-china-yes.php',
         'wp-china-yes/index.php',
@@ -28,7 +26,6 @@ function wpnav_is_wp_china_yes_active() {
         }
     }
 
-    // Also check if the WP_CHINA_YES constant is defined
     return defined('WP_CHINA_YES');
 }
 
@@ -46,10 +43,10 @@ if (isset($_POST['wpnav_basic_nonce']) && wp_verify_nonce($_POST['wpnav_basic_no
         $options['redirect_delay'] = isset($_POST['redirect_delay']) ? max(1, min(30, intval($_POST['redirect_delay']))) : 5;
         $options['open_in_new_tab'] = isset($_POST['open_in_new_tab']) ? 1 : 0;
         $options['url_format'] = isset($_POST['url_format']) ? sanitize_text_field($_POST['url_format']) : 'query';
-        $options['intercept_content'] = isset($_POST['intercept_content']) ? 1 : 0;
         $options['intercept_comments'] = isset($_POST['intercept_comments']) ? 1 : 0;
         $options['intercept_widgets'] = isset($_POST['intercept_widgets']) ? 1 : 0;
         $options['exclude_css_class'] = isset($_POST['exclude_css_class']) ? sanitize_text_field($_POST['exclude_css_class']) : 'no-redirect';
+        $options['show_external_icon'] = isset($_POST['show_external_icon']) ? 1 : 0;
         $options['admin_exempt'] = isset($_POST['admin_exempt']) ? 1 : 0;
         $options['cookie_duration'] = isset($_POST['cookie_duration']) ? max(1, min(365, intval($_POST['cookie_duration']))) : 30;
         $options['stats_retention'] = isset($_POST['stats_retention']) ? max(1, min(365, intval($_POST['stats_retention']))) : 90;
@@ -238,7 +235,7 @@ $custom_template_exists = file_exists(get_stylesheet_directory() . '/wpnav-redir
             <?php printf( esc_html__( 'Version: %s', 'wpnav-links' ), esc_html( WPNAV_LINKS_VERSION ) ); ?>
         </span>
         <a href="https://wpnav.com/document/wpnav-links" target="_blank" class="button button-secondary" style="margin-left: 10px;">
-            <?php esc_html_e( 'Document', 'wpnav-links' ); ?>
+            <?php esc_html_e( 'Documentation', 'wpnav-links' ); ?>
         </a>
         <a href="https://sharecms.com/forums/" target="_blank" class="button button-secondary">
             <?php esc_html_e( 'Support', 'wpnav-links' ); ?>
@@ -338,15 +335,20 @@ $custom_template_exists = file_exists(get_stylesheet_directory() . '/wpnav-redir
                         </tr>
                     </table>
 
-                    <h3><?php esc_html_e('Content Processing', 'wpnav-links'); ?></h3>
+                    <h3><?php esc_html_e('Link Display', 'wpnav-links'); ?></h3>
                     <table class="form-table">
                         <tr>
-                            <th scope="row"><?php esc_html_e('Process Post Content', 'wpnav-links'); ?></th>
+                            <th scope="row"><?php esc_html_e('Show External Icon', 'wpnav-links'); ?></th>
                             <td>
-                                <input type="checkbox" id="intercept_content" name="intercept_content" value="1" <?php checked(!empty($options['intercept_content'])); ?> />
+                                <input type="checkbox" id="show_external_icon" name="show_external_icon" value="1" <?php checked(!empty($options['show_external_icon'])); ?> />
-                                <label for="intercept_content"><?php esc_html_e('Process external links in post and page content', 'wpnav-links'); ?></label>
+                                <label for="show_external_icon"><?php esc_html_e('Show ↗ icon next to external links', 'wpnav-links'); ?></label>
+                                <p class="description"><?php esc_html_e('Display a small arrow icon next to external links to indicate they lead to external websites.', 'wpnav-links'); ?></p>
                             </td>
                         </tr>
+                    </table>
+
+                    <h3><?php esc_html_e('Content Processing', 'wpnav-links'); ?></h3>
+                    <table class="form-table">
                         <tr>
                             <th scope="row"><?php esc_html_e('Process Comments', 'wpnav-links'); ?></th>
                             <td>
@@ -680,7 +682,7 @@ $custom_template_exists = file_exists(get_stylesheet_directory() . '/wpnav-redir
                     <div class="notice notice-info inline">
                         <p>
                             <?php
-                            $wpcy_installed = class_exists('WP_China_Yes'); // Check if WP China Yes plugin is installed
+                            $wpcy_installed = class_exists('WP_China_Yes');
                             $wpcy_link = $wpcy_installed
                                 ? admin_url('admin.php?page=wp-china-yes')
                                 : 'https://wpcy.com';
@@ -977,6 +979,12 @@ $custom_template_exists = file_exists(get_stylesheet_directory() . '/wpnav-redir
     <div class="card">
         <h2><?php esc_html_e('System Information', 'wpnav-links'); ?></h2>
         <table class="wp-list-table widefat fixed">
+          <thead>
+              <tr>
+                  <th><?php _e('Metric', 'wpnav-links'); ?></th>
+                  <th><?php _e('Value', 'wpnav-links'); ?></th>
+              </tr>
+          </thead>
             <tbody>
                 <tr>
                     <th><?php esc_html_e('WordPress Version', 'wpnav-links'); ?></th>

assets/css/admin.css

@@ -417,9 +417,9 @@
     margin-top: 20px;
     position: relative;
     overflow: hidden;
-  background-image: url(../icons/i-like-food.svg);
+    background-image: url(../images/preview-bg.jpg);
-  background-position: left top;
+    background-position: right;
-  background-size: auto;
+    background-size: cover;
     background-repeat: repeat;
     background-attachment: fixed;
 }

assets/css/external-indicator.css

@@ -7,21 +7,21 @@ a[data-wpnav-external] .wpnav-external-icon {
     font-size: 0.8em;
     margin-left: 3px;
     opacity: 0.6;
-    transition: opacity 0.2s ease;
+    transition: opacity 0.2s;
     vertical-align: super;
     line-height: 1;
-    color: #646970;
+    color: rgb(100, 105, 112);
     text-decoration: none;
 }
 
 a[data-wpnav-external]:hover .wpnav-external-icon {
     opacity: 1;
-    color: #1d2327;
+    color: rgb(29, 35, 39);
 }
 
 a[data-wpnav-external]:focus .wpnav-external-icon {
     opacity: 1;
-    color: #2271b1;
+    color: rgb(34, 113, 177);
 }
 
 .wpnav-external-icon-box::after {
@@ -29,7 +29,7 @@ a[data-wpnav-external]:focus .wpnav-external-icon {
     font-size: 0.7em;
     margin-left: 2px;
     opacity: 0.5;
-    color: #646970;
+    color: rgb(100, 105, 112);
 }
 
 .wpnav-external-icon-arrow::after {
@@ -37,12 +37,12 @@ a[data-wpnav-external]:focus .wpnav-external-icon {
     font-size: 0.8em;
     margin-left: 2px;
     opacity: 0.6;
-    color: #646970;
+    color: rgb(100, 105, 112);
 }
 
 .entry-content a[data-wpnav-external] .wpnav-external-icon,
 .comment-content a[data-wpnav-external] .wpnav-external-icon {
-    color: #2271b1;
+    color: rgb(34, 113, 177);
     opacity: 0.7;
 }
 
@@ -52,13 +52,13 @@ a[data-wpnav-external]:focus .wpnav-external-icon {
 }
 
 .widget a[data-wpnav-external] .wpnav-external-icon {
-    color: #50575e;
+    color: rgb(80, 87, 94);
     opacity: 0.6;
 }
 
 .widget a[data-wpnav-external]:hover .wpnav-external-icon {
     opacity: 1;
-    color: #2271b1;
+    color: rgb(34, 113, 177);
 }
 
 .menu a[data-wpnav-external] .wpnav-external-icon,
@@ -69,13 +69,13 @@ a[data-wpnav-external]:focus .wpnav-external-icon {
 }
 
 .site-footer a[data-wpnav-external] .wpnav-external-icon {
-    color: #8c8f94;
+    color: rgb(140, 143, 148);
     opacity: 0.6;
 }
 
 .site-footer a[data-wpnav-external]:hover .wpnav-external-icon {
     opacity: 1;
-    color: #50575e;
+    color: rgb(80, 87, 94);
 }
 
 .wp-block-button__link[data-wpnav-external] .wpnav-external-icon,
@@ -92,7 +92,7 @@ a[data-wpnav-external]:focus .wpnav-external-icon {
     }
 
     a[data-wpnav-external]:hover .wpnav-external-icon {
-        color: #2271b1;
+        color: rgb(34, 113, 177);
     }
 }
 
@@ -116,7 +116,7 @@ a[data-wpnav-external]:focus .wpnav-external-icon {
 }
 
 a[data-wpnav-external]:focus-visible {
-    outline: 2px solid #2271b1;
+    outline: 2px solid rgb(34, 113, 177);
     outline-offset: 2px;
 }
 

assets/js/admin.js

@@ -164,7 +164,6 @@ jQuery(document).ready(function($) {
         }
     });
 
-    // Enhanced preview functionality
     $('#page_title').on('input', function() {
         $('#preview-page-title').text($(this).val());
     });
@@ -199,7 +198,6 @@ jQuery(document).ready(function($) {
         $('#preview-back-btn').text($(this).val());
     });
 
-    // Show/hide warning message functionality
     $('input[name="show_warning_message"], textarea[name="warning_text"]').on('change input', function() {
         var showWarning = $('input[name="show_warning_message"]').is(':checked');
         var warningText = $('textarea[name="warning_text"]').val().trim();
@@ -224,8 +222,6 @@ jQuery(document).ready(function($) {
             var showSecurityTips = $('input[name="show_security_tips"]').is(':checked');
             var showBackButton = $('input[name="show_back_button"]').is(':checked');
 
-            console.log('Updating preview - Template:', template, 'Color:', colorScheme);
-
             var $preview = $('.preview-container');
             $preview.removeClass('wpnav-color-blue wpnav-color-green wpnav-color-red');
             $preview.addClass('wpnav-color-' + colorScheme);
@@ -279,7 +275,7 @@ jQuery(document).ready(function($) {
                     $header.find('.wpnav-title').css('font-size', '36px');
                     break;
 
-                default: // default
+                default:
                     $container.css({
                         'max-width': '780px',
                         'padding': '40px',

assets/js/redirect.js

@@ -114,12 +114,14 @@
             $link.attr('href', redirectUrl);
             $link.attr('data-wpnav-external', '1');
 
+            if (wpnav_params.show_external_icon) {
                 this.addExternalIndicator($link);
+            }
         },
 
         addExternalIndicator: function($link) {
             if (!$link.find('.wpnav-external-icon').length) {
-                var iconHtml = '<span class="wpnav-external-icon" style="font-size: 0.8em; margin-left: 3px; opacity: 0.6; vertical-align: super; color: #646970; transition: opacity 0.2s ease;">↗</span>';
+                var iconHtml = '<span class="wpnav-external-icon" style="font-size: 0.8em; margin-left: 3px; opacity: 0.6; vertical-align: super; color: rgb(100, 105, 112); transition: opacity 0.2s;">↗</span>';
                 $link.append(iconHtml);
             }
         },
@@ -245,6 +247,7 @@
                 }
             });
 
+            if (wpnav_params.show_external_icon) {
                 $(document).on('mouseenter', 'a[data-wpnav-external]', function() {
                     $(this).find('.wpnav-external-icon').css('opacity', '1');
                 });
@@ -252,6 +255,7 @@
                 $(document).on('mouseleave', 'a[data-wpnav-external]', function() {
                     $(this).find('.wpnav-external-icon').css('opacity', '0.6');
                 });
+            }
         },
 
         optimizeForMobile: function() {

includes/class-public.php

@@ -39,6 +39,7 @@ class WPNAV_Public {
                 'redirect_method' => isset($this->options['url_format']) ? $this->options['url_format'] : 'query',
                 'url_encoding' => 'base64',
                 'permalink_structure' => get_option('permalink_structure') ? true : false,
+                'show_external_icon' => !empty($this->options['show_external_icon']),
                 'whitelist_domains' => $this->get_whitelist_domains(),
                 'strings' => array(
                     'external_link' => __('External link', 'wpnav-links'),
@@ -59,10 +60,6 @@ class WPNAV_Public {
     }
 
     private function setup_content_filters() {
-        if (isset($this->options['intercept_content']) && $this->options['intercept_content']) {
-            add_filter('the_content', array($this, 'process_content'));
-        }
-
         if (isset($this->options['intercept_comments']) && $this->options['intercept_comments']) {
             add_filter('comment_text', array($this, 'process_content'));
         }
@@ -119,7 +116,6 @@ class WPNAV_Public {
                 if ($this->options['open_in_new_tab']) {
                     $link->setAttribute('target', '_blank');
 
-                    // Add screen reader text for accessibility
                     $title = $link->getAttribute('title');
                     if (empty($title)) {
                         $link->setAttribute('title', __('External link (opens in a new window)', 'wpnav-links'));
@@ -236,7 +232,6 @@ class WPNAV_Public {
                         if (wpnav_params.open_new_tab) {
                             $link.attr('target', '_blank');
 
-                            // Add accessibility attributes
                             var currentTitle = $link.attr('title') || '';
                             if (!currentTitle.includes('<?php echo esc_js(__('opens in a new window', 'wpnav-links')); ?>')) {
                                 var newTitle = currentTitle ?
@@ -248,10 +243,21 @@ class WPNAV_Public {
 
                         $link.attr('href', getRedirectUrl(href));
                         $link.attr('data-wpnav-external', '1');
+
+                        if (wpnav_params.show_external_icon) {
+                            addExternalIcon($link);
+                        }
                     }
                 });
             }
 
+            function addExternalIcon($link) {
+                if (!$link.find('.wpnav-external-icon').length) {
+                    var iconHtml = '<span class="wpnav-external-icon" style="font-size: 0.8em; margin-left: 3px; opacity: 0.6; vertical-align: super; color: rgb(100, 105, 112); transition: opacity 0.2s;">↗</span>';
+                    $link.append(iconHtml);
+                }
+            }
+
             function isExternalLink(url) {
                 if (url.indexOf('://') === -1 && url.indexOf('//') !== 0) {
                     return false;
@@ -315,6 +321,16 @@ class WPNAV_Public {
             $(document).ready(function() {
                 processExternalLinks($('a:not([data-wpnav-external])'));
                 processAjaxContent();
+
+                if (wpnav_params.show_external_icon) {
+                    $(document).on('mouseenter', 'a[data-wpnav-external]', function() {
+                        $(this).find('.wpnav-external-icon').css('opacity', '1');
+                    });
+
+                    $(document).on('mouseleave', 'a[data-wpnav-external]', function() {
+                        $(this).find('.wpnav-external-icon').css('opacity', '0.6');
+                    });
+                }
             });
         })(jQuery);
         </script>

lib/plugin-update-checker/Puc/v5/PucFactory.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5;
+
+if ( !class_exists(PucFactory::class, false) ):
+
+	class PucFactory extends \YahnisElsts\PluginUpdateChecker\v5p3\PucFactory {
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Autoloader.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(Autoloader::class, false) ):
+
+	class Autoloader {
+		const DEFAULT_NS_PREFIX = 'YahnisElsts\\PluginUpdateChecker\\';
+
+		private $prefix;
+		private $rootDir;
+		private $libraryDir;
+
+		private $staticMap;
+
+		public function __construct() {
+			$this->rootDir = dirname(__FILE__) . '/';
+
+			$namespaceWithSlash = __NAMESPACE__ . '\\';
+			$this->prefix = $namespaceWithSlash;
+
+			$this->libraryDir = $this->rootDir . '../..';
+			if ( !self::isPhar() ) {
+				$this->libraryDir = realpath($this->libraryDir);
+			}
+			$this->libraryDir = $this->libraryDir . '/';
+
+			//Usually, dependencies like Parsedown are in the global namespace,
+			//but if someone adds a custom namespace to the entire library, they
+			//will be in the same namespace as this class.
+			$isCustomNamespace = (
+				substr($namespaceWithSlash, 0, strlen(self::DEFAULT_NS_PREFIX)) !== self::DEFAULT_NS_PREFIX
+			);
+			$libraryPrefix = $isCustomNamespace ? $namespaceWithSlash : '';
+
+			$this->staticMap = array(
+				$libraryPrefix . 'PucReadmeParser' => 'vendor/PucReadmeParser.php',
+				$libraryPrefix . 'Parsedown'       => 'vendor/Parsedown.php',
+			);
+
+			//Add the generic, major-version-only factory class to the static map.
+			$versionSeparatorPos = strrpos(__NAMESPACE__, '\\v');
+			if ( $versionSeparatorPos !== false ) {
+				$versionSegment = substr(__NAMESPACE__, $versionSeparatorPos + 1);
+				$pointPos = strpos($versionSegment, 'p');
+				if ( ($pointPos !== false) && ($pointPos > 1) ) {
+					$majorVersionSegment = substr($versionSegment, 0, $pointPos);
+					$majorVersionNs = __NAMESPACE__ . '\\' . $majorVersionSegment;
+					$this->staticMap[$majorVersionNs . '\\PucFactory'] =
+						'Puc/' . $majorVersionSegment . '/Factory.php';
+				}
+			}
+
+			spl_autoload_register(array($this, 'autoload'));
+		}
+
+		/**
+		 * Determine if this file is running as part of a Phar archive.
+		 *
+		 * @return bool
+		 */
+		private static function isPhar() {
+			//Check if the current file path starts with "phar://".
+			static $pharProtocol = 'phar://';
+			return (substr(__FILE__, 0, strlen($pharProtocol)) === $pharProtocol);
+		}
+
+		public function autoload($className) {
+			if ( isset($this->staticMap[$className]) && file_exists($this->libraryDir . $this->staticMap[$className]) ) {
+				include($this->libraryDir . $this->staticMap[$className]);
+				return;
+			}
+
+			if ( strpos($className, $this->prefix) === 0 ) {
+				$path = substr($className, strlen($this->prefix));
+				$path = str_replace(array('_', '\\'), '/', $path);
+				$path = $this->rootDir . $path . '.php';
+
+				if ( file_exists($path) ) {
+					include $path;
+				}
+			}
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/DebugBar/Extension.php

@@ -0,0 +1,199 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\PucFactory;
+use YahnisElsts\PluginUpdateChecker\v5p3\UpdateChecker;
+
+if ( !class_exists(Extension::class, false) ):
+
+	class Extension {
+		const RESPONSE_BODY_LENGTH_LIMIT = 4000;
+
+		/** @var UpdateChecker */
+		protected $updateChecker;
+		protected $panelClass = Panel::class;
+
+		public function __construct($updateChecker, $panelClass = null) {
+			$this->updateChecker = $updateChecker;
+			if ( isset($panelClass) ) {
+				$this->panelClass = $panelClass;
+			}
+
+			if ( (strpos($this->panelClass, '\\') === false) ) {
+				$this->panelClass = __NAMESPACE__ . '\\' . $this->panelClass;
+			}
+
+			add_filter('debug_bar_panels', array($this, 'addDebugBarPanel'));
+			add_action('debug_bar_enqueue_scripts', array($this, 'enqueuePanelDependencies'));
+
+			add_action('wp_ajax_puc_v5_debug_check_now', array($this, 'ajaxCheckNow'));
+		}
+
+		/**
+		 * Register the PUC Debug Bar panel.
+		 *
+		 * @param array $panels
+		 * @return array
+		 */
+		public function addDebugBarPanel($panels) {
+			if ( $this->updateChecker->userCanInstallUpdates() ) {
+				$panels[] = new $this->panelClass($this->updateChecker);
+			}
+			return $panels;
+		}
+
+		/**
+		 * Enqueue our Debug Bar scripts and styles.
+		 */
+		public function enqueuePanelDependencies() {
+			wp_enqueue_style(
+				'puc-debug-bar-style-v5',
+				$this->getLibraryUrl("/css/puc-debug-bar.css"),
+				array('debug-bar'),
+				'20221008'
+			);
+
+			wp_enqueue_script(
+				'puc-debug-bar-js-v5',
+				$this->getLibraryUrl("/js/debug-bar.js"),
+				array('jquery'),
+				'20221008'
+			);
+		}
+
+		/**
+		 * Run an update check and output the result. Useful for making sure that
+		 * the update checking process works as expected.
+		 */
+		public function ajaxCheckNow() {
+			//phpcs:ignore WordPress.Security.NonceVerification.Missing -- Nonce is checked in preAjaxRequest().
+			if ( !isset($_POST['uid']) || ($_POST['uid'] !== $this->updateChecker->getUniqueName('uid')) ) {
+				return;
+			}
+			$this->preAjaxRequest();
+			$update = $this->updateChecker->checkForUpdates();
+			if ( $update !== null ) {
+				echo "An update is available:";
+				//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_print_r -- For debugging output.
+				echo '<pre>', esc_html(print_r($update, true)), '</pre>';
+			} else {
+				echo 'No updates found.';
+			}
+
+			$errors = $this->updateChecker->getLastRequestApiErrors();
+			if ( !empty($errors) ) {
+				printf('<p>The update checker encountered %d API error%s.</p>', count($errors), (count($errors) > 1) ? 's' : '');
+
+				foreach (array_values($errors) as $num => $item) {
+					$wpError = $item['error'];
+					/** @var \WP_Error $wpError */
+					printf('<h4>%d) %s</h4>', intval($num + 1), esc_html($wpError->get_error_message()));
+
+					echo '<dl>';
+					printf('<dt>Error code:</dt><dd><code>%s</code></dd>', esc_html($wpError->get_error_code()));
+
+					if ( isset($item['url']) ) {
+						printf('<dt>Requested URL:</dt><dd><code>%s</code></dd>', esc_html($item['url']));
+					}
+
+					if ( isset($item['httpResponse']) ) {
+						if ( is_wp_error($item['httpResponse']) ) {
+							$httpError = $item['httpResponse'];
+							/** @var \WP_Error $httpError */
+							printf(
+								'<dt>WordPress HTTP API error:</dt><dd>%s (<code>%s</code>)</dd>',
+								esc_html($httpError->get_error_message()),
+								esc_html($httpError->get_error_code())
+							);
+						} else {
+							//Status code.
+							printf(
+								'<dt>HTTP status:</dt><dd><code>%d %s</code></dd>',
+								esc_html(wp_remote_retrieve_response_code($item['httpResponse'])),
+								esc_html(wp_remote_retrieve_response_message($item['httpResponse']))
+							);
+
+							//Headers.
+							echo '<dt>Response headers:</dt><dd><pre>';
+							foreach (wp_remote_retrieve_headers($item['httpResponse']) as $name => $value) {
+								printf("%s: %s\n", esc_html($name), esc_html($value));
+							}
+							echo '</pre></dd>';
+
+							//Body.
+							$body = wp_remote_retrieve_body($item['httpResponse']);
+							if ( $body === '' ) {
+								$body = '(Empty response.)';
+							} else if ( strlen($body) > self::RESPONSE_BODY_LENGTH_LIMIT ) {
+								$length = strlen($body);
+								$body = substr($body, 0, self::RESPONSE_BODY_LENGTH_LIMIT)
+									. sprintf("\n(Long string truncated. Total length: %d bytes.)", $length);
+							}
+
+							printf('<dt>Response body:</dt><dd><pre>%s</pre></dd>', esc_html($body));
+						}
+					}
+					echo '<dl>';
+				}
+			}
+
+			exit;
+		}
+
+		/**
+		 * Check access permissions and enable error display (for debugging).
+		 */
+		protected function preAjaxRequest() {
+			if ( !$this->updateChecker->userCanInstallUpdates() ) {
+				die('Access denied');
+			}
+			check_ajax_referer('puc-ajax');
+
+			//phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.runtime_configuration_error_reporting -- Part of a debugging feature.
+			error_reporting(E_ALL);
+			//phpcs:ignore WordPress.PHP.IniSet.display_errors_Blacklisted
+			@ini_set('display_errors', 'On');
+		}
+
+		/**
+		 * Remove hooks that were added by this extension.
+		 */
+		public function removeHooks() {
+			remove_filter('debug_bar_panels', array($this, 'addDebugBarPanel'));
+			remove_action('debug_bar_enqueue_scripts', array($this, 'enqueuePanelDependencies'));
+			remove_action('wp_ajax_puc_v5_debug_check_now', array($this, 'ajaxCheckNow'));
+		}
+
+		/**
+		 * @param string $filePath
+		 * @return string
+		 */
+		private function getLibraryUrl($filePath) {
+			$absolutePath = realpath(dirname(__FILE__) . '/../../../' . ltrim($filePath, '/'));
+
+			//Where is the library located inside the WordPress directory structure?
+			$absolutePath = PucFactory::normalizePath($absolutePath);
+
+			$pluginDir = PucFactory::normalizePath(WP_PLUGIN_DIR);
+			$muPluginDir = PucFactory::normalizePath(WPMU_PLUGIN_DIR);
+			$themeDir = PucFactory::normalizePath(get_theme_root());
+
+			if ( (strpos($absolutePath, $pluginDir) === 0) || (strpos($absolutePath, $muPluginDir) === 0) ) {
+				//It's part of a plugin.
+				return plugins_url(basename($absolutePath), $absolutePath);
+			} else if ( strpos($absolutePath, $themeDir) === 0 ) {
+				//It's part of a theme.
+				$relativePath = substr($absolutePath, strlen($themeDir) + 1);
+				$template = substr($relativePath, 0, strpos($relativePath, '/'));
+				$baseUrl = get_theme_root_uri($template);
+
+				if ( !empty($baseUrl) && $relativePath ) {
+					return $baseUrl . '/' . $relativePath;
+				}
+			}
+
+			return '';
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/DebugBar/Panel.php

@@ -0,0 +1,178 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\UpdateChecker;
+
+if ( !class_exists(Panel::class, false) && class_exists('Debug_Bar_Panel', false) ):
+
+	class Panel extends \Debug_Bar_Panel {
+		/** @var UpdateChecker */
+		protected $updateChecker;
+
+		private $responseBox = '<div class="puc-ajax-response" style="display: none;"></div>';
+
+		public function __construct($updateChecker) {
+			$this->updateChecker = $updateChecker;
+			$title = sprintf(
+				'<span class="puc-debug-menu-link-%s">PUC (%s)</span>',
+				esc_attr($this->updateChecker->getUniqueName('uid')),
+				$this->updateChecker->slug
+			);
+			parent::__construct($title);
+		}
+
+		public function render() {
+			printf(
+				'<div class="puc-debug-bar-panel-v5" id="%1$s" data-slug="%2$s" data-uid="%3$s" data-nonce="%4$s">',
+				esc_attr($this->updateChecker->getUniqueName('debug-bar-panel')),
+				esc_attr($this->updateChecker->slug),
+				esc_attr($this->updateChecker->getUniqueName('uid')),
+				esc_attr(wp_create_nonce('puc-ajax'))
+			);
+
+			$this->displayConfiguration();
+			$this->displayStatus();
+			$this->displayCurrentUpdate();
+
+			echo '</div>';
+		}
+
+		private function displayConfiguration() {
+			echo '<h3>Configuration</h3>';
+			echo '<table class="puc-debug-data">';
+			$this->displayConfigHeader();
+			$this->row('Slug', htmlentities($this->updateChecker->slug));
+			$this->row('DB option', htmlentities($this->updateChecker->optionName));
+
+			$requestInfoButton = $this->getMetadataButton();
+			$this->row('Metadata URL', htmlentities($this->updateChecker->metadataUrl) . ' ' . $requestInfoButton . $this->responseBox);
+
+			$scheduler = $this->updateChecker->scheduler;
+			if ( $scheduler->checkPeriod > 0 ) {
+				$this->row('Automatic checks', 'Every ' . $scheduler->checkPeriod . ' hours');
+			} else {
+				$this->row('Automatic checks', 'Disabled');
+			}
+
+			if ( isset($scheduler->throttleRedundantChecks) ) {
+				if ( $scheduler->throttleRedundantChecks && ($scheduler->checkPeriod > 0) ) {
+					$this->row(
+						'Throttling',
+						sprintf(
+							'Enabled. If an update is already available, check for updates every %1$d hours instead of every %2$d hours.',
+							$scheduler->throttledCheckPeriod,
+							$scheduler->checkPeriod
+						)
+					);
+				} else {
+					$this->row('Throttling', 'Disabled');
+				}
+			}
+
+			$this->updateChecker->onDisplayConfiguration($this);
+
+			echo '</table>';
+		}
+
+		protected function displayConfigHeader() {
+			//Do nothing. This should be implemented in subclasses.
+		}
+
+		protected function getMetadataButton() {
+			return '';
+		}
+
+		private function displayStatus() {
+			echo '<h3>Status</h3>';
+			echo '<table class="puc-debug-data">';
+			$state = $this->updateChecker->getUpdateState();
+			$checkNowButton = '';
+			if ( function_exists('get_submit_button')  ) {
+				$checkNowButton = get_submit_button(
+					'Check Now',
+					'secondary',
+					'puc-check-now-button',
+					false,
+					array('id' => $this->updateChecker->getUniqueName('check-now-button'))
+				);
+			}
+
+			if ( $state->getLastCheck() > 0 ) {
+				$this->row('Last check', $this->formatTimeWithDelta($state->getLastCheck()) . ' ' . $checkNowButton . $this->responseBox);
+			} else {
+				$this->row('Last check', 'Never');
+			}
+
+			$nextCheck = wp_next_scheduled($this->updateChecker->scheduler->getCronHookName());
+			$this->row('Next automatic check', $this->formatTimeWithDelta($nextCheck));
+
+			if ( $state->getCheckedVersion() !== '' ) {
+				$this->row('Checked version', htmlentities($state->getCheckedVersion()));
+				$this->row('Cached update', $state->getUpdate());
+			}
+			$this->row('Update checker class', htmlentities(get_class($this->updateChecker)));
+			echo '</table>';
+		}
+
+		private function displayCurrentUpdate() {
+			$update = $this->updateChecker->getUpdate();
+			if ( $update !== null ) {
+				echo '<h3>An Update Is Available</h3>';
+				echo '<table class="puc-debug-data">';
+				$fields = $this->getUpdateFields();
+				foreach($fields as $field) {
+					if ( property_exists($update, $field) ) {
+						$this->row(
+							ucwords(str_replace('_', ' ', $field)),
+							isset($update->$field) ? htmlentities($update->$field) : null
+						);
+					}
+				}
+				echo '</table>';
+			} else {
+				echo '<h3>No updates currently available</h3>';
+			}
+		}
+
+		protected function getUpdateFields() {
+			return array('version', 'download_url', 'slug',);
+		}
+
+		private function formatTimeWithDelta($unixTime) {
+			if ( empty($unixTime) ) {
+				return 'Never';
+			}
+
+			$delta = time() - $unixTime;
+			$result = human_time_diff(time(), $unixTime);
+			if ( $delta < 0 ) {
+				$result = 'after ' . $result;
+			} else {
+				$result = $result . ' ago';
+			}
+			$result .= ' (' . $this->formatTimestamp($unixTime) . ')';
+			return $result;
+		}
+
+		private function formatTimestamp($unixTime) {
+			return gmdate('Y-m-d H:i:s', $unixTime + (get_option('gmt_offset') * 3600));
+		}
+
+		public function row($name, $value) {
+			if ( is_object($value) || is_array($value) ) {
+				//This is specifically for debugging, so print_r() is fine.
+				//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_print_r
+				$value = '<pre>' . htmlentities(print_r($value, true)) . '</pre>';
+			} else if ($value === null) {
+				$value = '<code>null</code>';
+			}
+			printf(
+				'<tr><th scope="row">%1$s</th> <td>%2$s</td></tr>',
+				esc_html($name),
+				//phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Escaped above.
+				$value
+			);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/DebugBar/PluginExtension.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Plugin\UpdateChecker;
+
+if ( !class_exists(PluginExtension::class, false) ):
+
+	class PluginExtension extends Extension {
+		/** @var UpdateChecker */
+		protected $updateChecker;
+
+		public function __construct($updateChecker) {
+			parent::__construct($updateChecker, PluginPanel::class);
+
+			add_action('wp_ajax_puc_v5_debug_request_info', array($this, 'ajaxRequestInfo'));
+		}
+
+		/**
+		 * Request plugin info and output it.
+		 */
+		public function ajaxRequestInfo() {
+			//phpcs:ignore WordPress.Security.NonceVerification.Missing -- Nonce is checked in preAjaxRequest().
+			if ( !isset($_POST['uid']) || ($_POST['uid'] !== $this->updateChecker->getUniqueName('uid')) ) {
+				return;
+			}
+			$this->preAjaxRequest();
+			$info = $this->updateChecker->requestInfo();
+			if ( $info !== null ) {
+				echo 'Successfully retrieved plugin info from the metadata URL:';
+				//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_print_r -- For debugging output.
+				echo '<pre>', esc_html(print_r($info, true)), '</pre>';
+			} else {
+				echo 'Failed to retrieve plugin info from the metadata URL.';
+			}
+			exit;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/DebugBar/PluginPanel.php

@@ -0,0 +1,41 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Plugin\UpdateChecker;
+
+if ( !class_exists(PluginPanel::class, false) ):
+
+	class PluginPanel extends Panel {
+		/**
+		 * @var UpdateChecker
+		 */
+		protected $updateChecker;
+
+		protected function displayConfigHeader() {
+			$this->row('Plugin file', htmlentities($this->updateChecker->pluginFile));
+			parent::displayConfigHeader();
+		}
+
+		protected function getMetadataButton() {
+			$requestInfoButton = '';
+			if ( function_exists('get_submit_button') ) {
+				$requestInfoButton = get_submit_button(
+					'Request Info',
+					'secondary',
+					'puc-request-info-button',
+					false,
+					array('id' => $this->updateChecker->getUniqueName('request-info-button'))
+				);
+			}
+			return $requestInfoButton;
+		}
+
+		protected function getUpdateFields() {
+			return array_merge(
+				parent::getUpdateFields(),
+				array('homepage', 'upgrade_notice', 'tested',)
+			);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/DebugBar/ThemePanel.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Theme\UpdateChecker;
+
+if ( !class_exists(ThemePanel::class, false) ):
+
+	class ThemePanel extends Panel {
+		/**
+		 * @var UpdateChecker
+		 */
+		protected $updateChecker;
+
+		protected function displayConfigHeader() {
+			$this->row('Theme directory', htmlentities($this->updateChecker->directoryName));
+			parent::displayConfigHeader();
+		}
+
+		protected function getUpdateFields() {
+			return array_merge(parent::getUpdateFields(), array('details_url'));
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/InstalledPackage.php

@@ -0,0 +1,105 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(InstalledPackage::class, false) ):
+
+	/**
+	 * This class represents a currently installed plugin or theme.
+	 *
+	 * Not to be confused with the "package" field in WP update API responses that contains
+	 * the download URL of a the new version.
+	 */
+	abstract class InstalledPackage {
+		/**
+		 * @var UpdateChecker
+		 */
+		protected $updateChecker;
+
+		public function __construct($updateChecker) {
+			$this->updateChecker = $updateChecker;
+		}
+
+		/**
+		 * Get the currently installed version of the plugin or theme.
+		 *
+		 * @return string|null Version number.
+		 */
+		abstract public function getInstalledVersion();
+
+		/**
+		 * Get the full path of the plugin or theme directory (without a trailing slash).
+		 *
+		 * @return string
+		 */
+		abstract public function getAbsoluteDirectoryPath();
+
+		/**
+		 * Check whether a regular file exists in the package's directory.
+		 *
+		 * @param string $relativeFileName File name relative to the package directory.
+		 * @return bool
+		 */
+		public function fileExists($relativeFileName) {
+			return is_file(
+				$this->getAbsoluteDirectoryPath()
+				. DIRECTORY_SEPARATOR
+				. ltrim($relativeFileName, '/\\')
+			);
+		}
+
+		/* -------------------------------------------------------------------
+		 * File header parsing
+		 * -------------------------------------------------------------------
+		 */
+
+		/**
+		 * Parse plugin or theme metadata from the header comment.
+		 *
+		 * This is basically a simplified version of the get_file_data() function from /wp-includes/functions.php.
+		 * It's intended as a utility for subclasses that detect updates by parsing files in a VCS.
+		 *
+		 * @param string|null $content File contents.
+		 * @return string[]
+		 */
+		public function getFileHeader($content) {
+			$content = (string)$content;
+
+			//WordPress only looks at the first 8 KiB of the file, so we do the same.
+			$content = substr($content, 0, 8192);
+			//Normalize line endings.
+			$content = str_replace("\r", "\n", $content);
+
+			$headers = $this->getHeaderNames();
+			$results = array();
+			foreach ($headers as $field => $name) {
+				$success = preg_match('/^[ \t\/*#@]*' . preg_quote($name, '/') . ':(.*)$/mi', $content, $matches);
+
+				if ( ($success === 1) && $matches[1] ) {
+					$value = $matches[1];
+					if ( function_exists('_cleanup_header_comment') ) {
+						$value = _cleanup_header_comment($value);
+					}
+					$results[$field] = $value;
+				} else {
+					$results[$field] = '';
+				}
+			}
+
+			return $results;
+		}
+
+		/**
+		 * @return array Format: ['HeaderKey' => 'Header Name']
+		 */
+		abstract protected function getHeaderNames();
+
+		/**
+		 * Get the value of a specific plugin or theme header.
+		 *
+		 * @param string $headerName
+		 * @return string Either the value of the header, or an empty string if the header doesn't exist.
+		 */
+		abstract public function getHeaderValue($headerName);
+
+	}
+endif;

lib/plugin-update-checker/Puc/v5p3/Metadata.php

@@ -0,0 +1,162 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+use LogicException;
+use stdClass;
+use WP_Error;
+
+if ( !class_exists(Metadata::class, false) ):
+
+	/**
+	 * A base container for holding information about updates and plugin metadata.
+	 *
+	 * @author Janis Elsts
+	 * @copyright 2016
+	 * @access public
+	 */
+	abstract class Metadata {
+		/**
+		 * Additional dynamic properties, usually copied from the API response.
+		 *
+		 * @var array<string,mixed>
+		 */
+		protected $extraProperties = array();
+
+		/**
+		 * Create an instance of this class from a JSON document.
+		 *
+		 * @abstract
+		 * @param string $json
+		 * @return self
+		 */
+		public static function fromJson($json) {
+			throw new LogicException('The ' . __METHOD__ . ' method must be implemented by subclasses');
+		}
+
+		/**
+		 * @param string $json
+		 * @param self $target
+		 * @return bool
+		 */
+		protected static function createFromJson($json, $target) {
+			/** @var \StdClass $apiResponse */
+			$apiResponse = json_decode($json);
+			if ( empty($apiResponse) || !is_object($apiResponse) ){
+				$errorMessage = "Failed to parse update metadata. Try validating your .json file with https://jsonlint.com/";
+				do_action('puc_api_error', new WP_Error('puc-invalid-json', $errorMessage));
+				//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error -- For plugin developers.
+				trigger_error(esc_html($errorMessage), E_USER_NOTICE);
+				return false;
+			}
+
+			$valid = $target->validateMetadata($apiResponse);
+			if ( is_wp_error($valid) ){
+				do_action('puc_api_error', $valid);
+				//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error -- For plugin developers.
+				trigger_error(esc_html($valid->get_error_message()), E_USER_NOTICE);
+				return false;
+			}
+
+			foreach(get_object_vars($apiResponse) as $key => $value){
+				$target->$key = $value;
+			}
+
+			return true;
+		}
+
+		/**
+		 * No validation by default! Subclasses should check that the required fields are present.
+		 *
+		 * @param \StdClass $apiResponse
+		 * @return bool|\WP_Error
+		 */
+		protected function validateMetadata($apiResponse) {
+			return true;
+		}
+
+		/**
+		 * Create a new instance by copying the necessary fields from another object.
+		 *
+		 * @abstract
+		 * @param \StdClass|self $object The source object.
+		 * @return self The new copy.
+		 */
+		public static function fromObject($object) {
+			throw new LogicException('The ' . __METHOD__ . ' method must be implemented by subclasses');
+		}
+
+		/**
+		 * Create an instance of StdClass that can later be converted back to an
+		 * update or info container. Useful for serialization and caching, as it
+		 * avoids the "incomplete object" problem if the cached value is loaded
+		 * before this class.
+		 *
+		 * @return \StdClass
+		 */
+		public function toStdClass() {
+			$object = new stdClass();
+			$this->copyFields($this, $object);
+			return $object;
+		}
+
+		/**
+		 * Transform the metadata into the format used by WordPress core.
+		 *
+		 * @return object
+		 */
+		abstract public function toWpFormat();
+
+		/**
+		 * Copy known fields from one object to another.
+		 *
+		 * @param \StdClass|self $from
+		 * @param \StdClass|self $to
+		 */
+		protected function copyFields($from, $to) {
+			$fields = $this->getFieldNames();
+
+			if ( property_exists($from, 'slug') && !empty($from->slug) ) {
+				//Let plugins add extra fields without having to create subclasses.
+				$fields = apply_filters($this->getPrefixedFilter('retain_fields') . '-' . $from->slug, $fields);
+			}
+
+			foreach ($fields as $field) {
+				if ( property_exists($from, $field) ) {
+					$to->$field = $from->$field;
+				}
+			}
+		}
+
+		/**
+		 * @return string[]
+		 */
+		protected function getFieldNames() {
+			return array();
+		}
+
+		/**
+		 * @param string $tag
+		 * @return string
+		 */
+		protected function getPrefixedFilter($tag) {
+			return 'puc_' . $tag;
+		}
+
+		public function __set($name, $value) {
+			$this->extraProperties[$name] = $value;
+		}
+
+		public function __get($name) {
+			return isset($this->extraProperties[$name]) ? $this->extraProperties[$name] : null;
+		}
+
+		public function __isset($name) {
+			return isset($this->extraProperties[$name]);
+		}
+
+		public function __unset($name) {
+			unset($this->extraProperties[$name]);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/OAuthSignature.php

@@ -0,0 +1,102 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(OAuthSignature::class, false) ):
+
+	/**
+	 * A basic signature generator for zero-legged OAuth 1.0.
+	 */
+	class OAuthSignature {
+		private $consumerKey = '';
+		private $consumerSecret = '';
+
+		public function __construct($consumerKey, $consumerSecret) {
+			$this->consumerKey = $consumerKey;
+			$this->consumerSecret = $consumerSecret;
+		}
+
+		/**
+		 * Sign a URL using OAuth 1.0.
+		 *
+		 * @param string $url The URL to be signed. It may contain query parameters.
+		 * @param string $method HTTP method such as "GET", "POST" and so on.
+		 * @return string The signed URL.
+		 */
+		public function sign($url, $method = 'GET') {
+			$parameters = array();
+
+			//Parse query parameters.
+			$query = wp_parse_url($url, PHP_URL_QUERY);
+			if ( !empty($query) ) {
+				parse_str($query, $parsedParams);
+				if ( is_array($parsedParams) ) {
+					$parameters = $parsedParams;
+				}
+				//Remove the query string from the URL. We'll replace it later.
+				$url = substr($url, 0, strpos($url, '?'));
+			}
+
+			$parameters = array_merge(
+				$parameters,
+				array(
+					'oauth_consumer_key' => $this->consumerKey,
+					'oauth_nonce' => $this->nonce(),
+					'oauth_signature_method' => 'HMAC-SHA1',
+					'oauth_timestamp' => time(),
+					'oauth_version' => '1.0',
+				)
+			);
+			unset($parameters['oauth_signature']);
+
+			//Parameters must be sorted alphabetically before signing.
+			ksort($parameters);
+
+			//The most complicated part of the request - generating the signature.
+			//The string to sign contains the HTTP method, the URL path, and all of
+			//our query parameters. Everything is URL encoded. Then we concatenate
+			//them with ampersands into a single string to hash.
+			$encodedVerb = urlencode($method);
+			$encodedUrl = urlencode($url);
+			$encodedParams = urlencode(http_build_query($parameters, '', '&'));
+
+			$stringToSign = $encodedVerb . '&' . $encodedUrl . '&' . $encodedParams;
+
+			//Since we only have one OAuth token (the consumer secret) we only have
+			//to use it as our HMAC key. However, we still have to append an & to it
+			//as if we were using it with additional tokens.
+			$secret = urlencode($this->consumerSecret) . '&';
+
+			//The signature is a hash of the consumer key and the base string. Note
+			//that we have to get the raw output from hash_hmac and base64 encode
+			//the binary data result.
+			$parameters['oauth_signature'] = base64_encode(hash_hmac('sha1', $stringToSign, $secret, true));
+
+			return ($url . '?' . http_build_query($parameters));
+		}
+
+		/**
+		 * Generate a random nonce.
+		 *
+		 * @return string
+		 */
+		private function nonce() {
+			$mt = microtime();
+
+			$rand = null;
+			if ( is_callable('random_bytes') ) {
+				try {
+					$rand = random_bytes(16);
+				} catch (\Exception $ex) {
+					//Fall back to mt_rand (below).
+				}
+			}
+			if ( $rand === null ) {
+				//phpcs:ignore WordPress.WP.AlternativeFunctions.rand_mt_rand
+				$rand = function_exists('wp_rand') ? wp_rand() : mt_rand();
+			}
+
+			return md5($mt . '_' . $rand);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Plugin/Package.php

@@ -0,0 +1,188 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\InstalledPackage;
+use YahnisElsts\PluginUpdateChecker\v5p3\PucFactory;
+
+if ( !class_exists(Package::class, false) ):
+
+	class Package extends InstalledPackage {
+		/**
+		 * @var UpdateChecker
+		 */
+		protected $updateChecker;
+
+		/**
+		 * @var string Full path of the main plugin file.
+		 */
+		protected $pluginAbsolutePath = '';
+
+		/**
+		 * @var string Plugin basename.
+		 */
+		private $pluginFile;
+
+		/**
+		 * @var string|null
+		 */
+		private $cachedInstalledVersion = null;
+
+		public function __construct($pluginAbsolutePath, $updateChecker) {
+			$this->pluginAbsolutePath = $pluginAbsolutePath;
+			$this->pluginFile = plugin_basename($this->pluginAbsolutePath);
+
+			parent::__construct($updateChecker);
+
+			//Clear the version number cache when something - anything - is upgraded or WP clears the update cache.
+			add_filter('upgrader_post_install', array($this, 'clearCachedVersion'));
+			add_action('delete_site_transient_update_plugins', array($this, 'clearCachedVersion'));
+		}
+
+		public function getInstalledVersion() {
+			if ( isset($this->cachedInstalledVersion) ) {
+				return $this->cachedInstalledVersion;
+			}
+
+			$pluginHeader = $this->getPluginHeader();
+			if ( isset($pluginHeader['Version']) ) {
+				$this->cachedInstalledVersion = $pluginHeader['Version'];
+				return $pluginHeader['Version'];
+			} else {
+				//This can happen if the filename points to something that is not a plugin.
+				$this->updateChecker->triggerError(
+					sprintf(
+						"Cannot read the Version header for '%s'. The filename is incorrect or is not a plugin.",
+						$this->updateChecker->pluginFile
+					),
+					E_USER_WARNING
+				);
+				return null;
+			}
+		}
+
+		/**
+		 * Clear the cached plugin version. This method can be set up as a filter (hook) and will
+		 * return the filter argument unmodified.
+		 *
+		 * @param mixed $filterArgument
+		 * @return mixed
+		 */
+		public function clearCachedVersion($filterArgument = null) {
+			$this->cachedInstalledVersion = null;
+			return $filterArgument;
+		}
+
+		public function getAbsoluteDirectoryPath() {
+			return dirname($this->pluginAbsolutePath);
+		}
+
+		/**
+		 * Get the value of a specific plugin or theme header.
+		 *
+		 * @param string $headerName
+		 * @param string $defaultValue
+		 * @return string Either the value of the header, or $defaultValue if the header doesn't exist or is empty.
+		 */
+		public function getHeaderValue($headerName, $defaultValue = '') {
+			$headers = $this->getPluginHeader();
+			if ( isset($headers[$headerName]) && ($headers[$headerName] !== '') ) {
+				return $headers[$headerName];
+			}
+			return $defaultValue;
+		}
+
+		protected function getHeaderNames() {
+			return array(
+				'Name'              => 'Plugin Name',
+				'PluginURI'         => 'Plugin URI',
+				'Version'           => 'Version',
+				'Description'       => 'Description',
+				'Author'            => 'Author',
+				'AuthorURI'         => 'Author URI',
+				'TextDomain'        => 'Text Domain',
+				'DomainPath'        => 'Domain Path',
+				'Network'           => 'Network',
+
+				//The newest WordPress version that this plugin requires or has been tested with.
+				//We support several different formats for compatibility with other libraries.
+				'Tested WP'         => 'Tested WP',
+				'Requires WP'       => 'Requires WP',
+				'Tested up to'      => 'Tested up to',
+				'Requires at least' => 'Requires at least',
+			);
+		}
+
+		/**
+		 * Get the translated plugin title.
+		 *
+		 * @return string
+		 */
+		public function getPluginTitle() {
+			$title = '';
+			$header = $this->getPluginHeader();
+			if ( $header && !empty($header['Name']) && isset($header['TextDomain']) ) {
+				$title = translate($header['Name'], $header['TextDomain']);
+			}
+			return $title;
+		}
+
+		/**
+		 * Get plugin's metadata from its file header.
+		 *
+		 * @return array
+		 */
+		public function getPluginHeader() {
+			if ( !is_file($this->pluginAbsolutePath) ) {
+				//This can happen if the plugin filename is wrong.
+				$this->updateChecker->triggerError(
+					sprintf(
+						"Can't to read the plugin header for '%s'. The file does not exist.",
+						$this->updateChecker->pluginFile
+					),
+					E_USER_WARNING
+				);
+				return array();
+			}
+
+			if ( !function_exists('get_plugin_data') ) {
+				require_once(ABSPATH . '/wp-admin/includes/plugin.php');
+			}
+			return get_plugin_data($this->pluginAbsolutePath, false, false);
+		}
+
+		public function removeHooks() {
+			remove_filter('upgrader_post_install', array($this, 'clearCachedVersion'));
+			remove_action('delete_site_transient_update_plugins', array($this, 'clearCachedVersion'));
+		}
+
+		/**
+		 * Check if the plugin file is inside the mu-plugins directory.
+		 *
+		 * @return bool
+		 */
+		public function isMuPlugin() {
+			static $cachedResult = null;
+
+			if ( $cachedResult === null ) {
+				if ( !defined('WPMU_PLUGIN_DIR') || !is_string(WPMU_PLUGIN_DIR) ) {
+					$cachedResult = false;
+					return $cachedResult;
+				}
+
+				//Convert both paths to the canonical form before comparison.
+				$muPluginDir = realpath(WPMU_PLUGIN_DIR);
+				$pluginPath  = realpath($this->pluginAbsolutePath);
+				//If realpath() fails, just normalize the syntax instead.
+				if (($muPluginDir === false) || ($pluginPath === false)) {
+					$muPluginDir = PucFactory::normalizePath(WPMU_PLUGIN_DIR);
+					$pluginPath  = PucFactory::normalizePath($this->pluginAbsolutePath);
+				}
+
+				$cachedResult = (strpos($pluginPath, $muPluginDir) === 0);
+			}
+
+			return $cachedResult;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Plugin/PluginInfo.php

@@ -0,0 +1,136 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Metadata;
+
+if ( !class_exists(PluginInfo::class, false) ):
+
+	/**
+	 * A container class for holding and transforming various plugin metadata.
+	 *
+	 * @author Janis Elsts
+	 * @copyright 2016
+	 * @access public
+	 */
+	class PluginInfo extends Metadata {
+		//Most fields map directly to the contents of the plugin's info.json file.
+		//See the relevant docs for a description of their meaning.
+		public $name;
+		public $slug;
+		public $version;
+		public $homepage;
+		public $sections = array();
+		public $download_url;
+
+		public $banners;
+		public $icons = array();
+		public $translations = array();
+
+		public $author;
+		public $author_homepage;
+
+		public $requires;
+		public $tested;
+		public $requires_php;
+		public $upgrade_notice;
+
+		public $rating;
+		public $num_ratings;
+		public $downloaded;
+		public $active_installs;
+		public $last_updated;
+
+		public $id = 0; //The native WP.org API returns numeric plugin IDs, but they're not used for anything.
+
+		public $filename; //Plugin filename relative to the plugins directory.
+
+		/**
+		 * Create a new instance of Plugin Info from JSON-encoded plugin info
+		 * returned by an external update API.
+		 *
+		 * @param string $json Valid JSON string representing plugin info.
+		 * @return self|null New instance of Plugin Info, or NULL on error.
+		 */
+		public static function fromJson($json){
+			$instance = new self();
+
+			if ( !parent::createFromJson($json, $instance) ) {
+				return null;
+			}
+
+			//json_decode decodes assoc. arrays as objects. We want them as arrays.
+			$instance->sections = (array)$instance->sections;
+			$instance->icons = (array)$instance->icons;
+
+			return $instance;
+		}
+
+		/**
+		 * Very, very basic validation.
+		 *
+		 * @param \StdClass $apiResponse
+		 * @return bool|\WP_Error
+		 */
+		protected function validateMetadata($apiResponse) {
+			if (
+				!isset($apiResponse->name, $apiResponse->version)
+				|| empty($apiResponse->name)
+				|| empty($apiResponse->version)
+			) {
+				return new \WP_Error(
+					'puc-invalid-metadata',
+					"The plugin metadata file does not contain the required 'name' and/or 'version' keys."
+				);
+			}
+			return true;
+		}
+
+
+		/**
+		 * Transform plugin info into the format used by the native WordPress.org API
+		 *
+		 * @return object
+		 */
+		public function toWpFormat(){
+			$info = new \stdClass;
+
+			//The custom update API is built so that many fields have the same name and format
+			//as those returned by the native WordPress.org API. These can be assigned directly.
+			$sameFormat = array(
+				'name', 'slug', 'version', 'requires', 'tested', 'rating', 'upgrade_notice',
+				'num_ratings', 'downloaded', 'active_installs', 'homepage', 'last_updated',
+				'requires_php',
+			);
+			foreach($sameFormat as $field){
+				if ( isset($this->$field) ) {
+					$info->$field = $this->$field;
+				} else {
+					$info->$field = null;
+				}
+			}
+
+			//Other fields need to be renamed and/or transformed.
+			$info->download_link = $this->download_url;
+			$info->author = $this->getFormattedAuthor();
+			$info->sections = array_merge(array('description' => ''), $this->sections);
+
+			if ( !empty($this->banners) ) {
+				//WP expects an array with two keys: "high" and "low". Both are optional.
+				//Docs: https://wordpress.org/plugins/about/faq/#banners
+				$info->banners = is_object($this->banners) ? get_object_vars($this->banners) : $this->banners;
+				$info->banners = array_intersect_key($info->banners, array('high' => true, 'low' => true));
+			}
+
+			return $info;
+		}
+
+		protected function getFormattedAuthor() {
+			if ( !empty($this->author_homepage) ){
+				/** @noinspection HtmlUnknownTarget */
+				return sprintf('<a href="%s">%s</a>', $this->author_homepage, $this->author);
+			}
+			return $this->author;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Plugin/Ui.php

@@ -0,0 +1,294 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+
+if ( !class_exists('Ui', false) ):
+	/**
+	 * Additional UI elements for plugins.
+	 */
+	class Ui {
+		private $updateChecker;
+		private $manualCheckErrorTransient = '';
+
+		/**
+		 * @param UpdateChecker $updateChecker
+		 */
+		public function __construct($updateChecker) {
+			$this->updateChecker = $updateChecker;
+			$this->manualCheckErrorTransient = $this->updateChecker->getUniqueName('manual_check_errors');
+
+			add_action('admin_init', array($this, 'onAdminInit'));
+		}
+
+		public function onAdminInit() {
+			if ( $this->updateChecker->userCanInstallUpdates() ) {
+				$this->handleManualCheck();
+
+				add_filter('plugin_row_meta', array($this, 'addViewDetailsLink'), 10, 3);
+				add_filter('plugin_row_meta', array($this, 'addCheckForUpdatesLink'), 10, 2);
+				add_action('all_admin_notices', array($this, 'displayManualCheckResult'));
+			}
+		}
+
+		/**
+		 * Add a "View Details" link to the plugin row in the "Plugins" page. By default,
+		 * the new link will appear before the "Visit plugin site" link (if present).
+		 *
+		 * You can change the link text by using the "puc_view_details_link-$slug" filter.
+		 * Returning an empty string from the filter will disable the link.
+		 *
+		 * You can change the position of the link using the
+		 * "puc_view_details_link_position-$slug" filter.
+		 * Returning 'before' or 'after' will place the link immediately before/after
+		 * the "Visit plugin site" link.
+		 * Returning 'append' places the link after any existing links at the time of the hook.
+		 * Returning 'replace' replaces the "Visit plugin site" link.
+		 * Returning anything else disables the link when there is a "Visit plugin site" link.
+		 *
+		 * If there is no "Visit plugin site" link 'append' is always used!
+		 *
+		 * @param array $pluginMeta Array of meta links.
+		 * @param string $pluginFile
+		 * @param array $pluginData Array of plugin header data.
+		 * @return array
+		 */
+		public function addViewDetailsLink($pluginMeta, $pluginFile, $pluginData = array()) {
+			if ( $this->isMyPluginFile($pluginFile) && !isset($pluginData['slug']) ) {
+				$linkText = apply_filters($this->updateChecker->getUniqueName('view_details_link'), __('View details'));
+				if ( !empty($linkText) ) {
+					$viewDetailsLinkPosition = 'append';
+
+					//Find the "Visit plugin site" link (if present).
+					$visitPluginSiteLinkIndex = count($pluginMeta) - 1;
+					if ( $pluginData['PluginURI'] ) {
+						$escapedPluginUri = esc_url($pluginData['PluginURI']);
+						foreach ($pluginMeta as $linkIndex => $existingLink) {
+							if ( strpos($existingLink, $escapedPluginUri) !== false ) {
+								$visitPluginSiteLinkIndex = $linkIndex;
+								$viewDetailsLinkPosition = apply_filters(
+									$this->updateChecker->getUniqueName('view_details_link_position'),
+									'before'
+								);
+								break;
+							}
+						}
+					}
+
+					$viewDetailsLink = sprintf('<a href="%s" class="thickbox open-plugin-details-modal" aria-label="%s" data-title="%s">%s</a>',
+						esc_url(network_admin_url('plugin-install.php?tab=plugin-information&plugin=' . urlencode($this->updateChecker->slug) .
+							'&TB_iframe=true&width=600&height=550')),
+						esc_attr(sprintf(__('More information about %s'), $pluginData['Name'])),
+						esc_attr($pluginData['Name']),
+						$linkText
+					);
+					switch ($viewDetailsLinkPosition) {
+						case 'before':
+							array_splice($pluginMeta, $visitPluginSiteLinkIndex, 0, $viewDetailsLink);
+							break;
+						case 'after':
+							array_splice($pluginMeta, $visitPluginSiteLinkIndex + 1, 0, $viewDetailsLink);
+							break;
+						case 'replace':
+							$pluginMeta[$visitPluginSiteLinkIndex] = $viewDetailsLink;
+							break;
+						case 'append':
+						default:
+							$pluginMeta[] = $viewDetailsLink;
+							break;
+					}
+				}
+			}
+			return $pluginMeta;
+		}
+
+		/**
+		 * Add a "Check for updates" link to the plugin row in the "Plugins" page. By default,
+		 * the new link will appear after the "Visit plugin site" link if present, otherwise
+		 * after the "View plugin details" link.
+		 *
+		 * You can change the link text by using the "puc_manual_check_link-$slug" filter.
+		 * Returning an empty string from the filter will disable the link.
+		 *
+		 * @param array $pluginMeta Array of meta links.
+		 * @param string $pluginFile
+		 * @return array
+		 */
+		public function addCheckForUpdatesLink($pluginMeta, $pluginFile) {
+			if ( $this->isMyPluginFile($pluginFile) ) {
+				$linkUrl = wp_nonce_url(
+					add_query_arg(
+						array(
+							'puc_check_for_updates' => 1,
+							'puc_slug'              => $this->updateChecker->slug,
+						),
+						self_admin_url('plugins.php')
+					),
+					'puc_check_for_updates'
+				);
+
+				$linkText = apply_filters(
+					$this->updateChecker->getUniqueName('manual_check_link'),
+					__('Check for updates', 'plugin-update-checker')
+				);
+				if ( !empty($linkText) ) {
+					/** @noinspection HtmlUnknownTarget */
+					$pluginMeta[] = sprintf('<a href="%s">%s</a>', esc_attr($linkUrl), $linkText);
+				}
+			}
+			return $pluginMeta;
+		}
+
+		protected function isMyPluginFile($pluginFile) {
+			return ($pluginFile == $this->updateChecker->pluginFile)
+				|| (!empty($this->updateChecker->muPluginFile) && ($pluginFile == $this->updateChecker->muPluginFile));
+		}
+
+		/**
+		 * Check for updates when the user clicks the "Check for updates" link.
+		 *
+		 * @see self::addCheckForUpdatesLink()
+		 *
+		 * @return void
+		 */
+		public function handleManualCheck() {
+			$shouldCheck =
+				isset($_GET['puc_check_for_updates'], $_GET['puc_slug'])
+				&& $_GET['puc_slug'] == $this->updateChecker->slug
+				&& check_admin_referer('puc_check_for_updates');
+
+			if ( $shouldCheck ) {
+				$update = $this->updateChecker->checkForUpdates();
+				$status = ($update === null) ? 'no_update' : 'update_available';
+				$lastRequestApiErrors = $this->updateChecker->getLastRequestApiErrors();
+
+				if ( ($update === null) && !empty($lastRequestApiErrors) ) {
+					//Some errors are not critical. For example, if PUC tries to retrieve the readme.txt
+					//file from GitHub and gets a 404, that's an API error, but it doesn't prevent updates
+					//from working. Maybe the plugin simply doesn't have a readme.
+					//Let's only show important errors.
+					$foundCriticalErrors = false;
+					$questionableErrorCodes = array(
+						'puc-github-http-error',
+						'puc-gitlab-http-error',
+						'puc-bitbucket-http-error',
+					);
+
+					foreach ($lastRequestApiErrors as $item) {
+						$wpError = $item['error'];
+						/** @var \WP_Error $wpError */
+						if ( !in_array($wpError->get_error_code(), $questionableErrorCodes) ) {
+							$foundCriticalErrors = true;
+							break;
+						}
+					}
+
+					if ( $foundCriticalErrors ) {
+						$status = 'error';
+						set_site_transient($this->manualCheckErrorTransient, $lastRequestApiErrors, 60);
+					}
+				}
+
+				wp_redirect(add_query_arg(
+					array(
+						'puc_update_check_result' => $status,
+						'puc_slug'                => $this->updateChecker->slug,
+					),
+					self_admin_url('plugins.php')
+				));
+				exit;
+			}
+		}
+
+		/**
+		 * Display the results of a manual update check.
+		 *
+		 * @see self::handleManualCheck()
+		 *
+		 * You can change the result message by using the "puc_manual_check_message-$slug" filter.
+		 */
+		public function displayManualCheckResult() {
+			//phpcs:disable WordPress.Security.NonceVerification.Recommended -- Just displaying a message.
+			if ( isset($_GET['puc_update_check_result'], $_GET['puc_slug']) && ($_GET['puc_slug'] == $this->updateChecker->slug) ) {
+				$status = sanitize_key($_GET['puc_update_check_result']);
+				$title = $this->updateChecker->getInstalledPackage()->getPluginTitle();
+				$noticeClass = 'updated notice-success';
+				$details = '';
+
+				if ( $status == 'no_update' ) {
+					$message = sprintf(_x('The %s plugin is up to date.', 'the plugin title', 'plugin-update-checker'), $title);
+				} else if ( $status == 'update_available' ) {
+					$message = sprintf(_x('A new version of the %s plugin is available.', 'the plugin title', 'plugin-update-checker'), $title);
+				} else if ( $status === 'error' ) {
+					$message = sprintf(_x('Could not determine if updates are available for %s.', 'the plugin title', 'plugin-update-checker'), $title);
+					$noticeClass = 'error notice-error';
+
+					$details = $this->formatManualCheckErrors(get_site_transient($this->manualCheckErrorTransient));
+					delete_site_transient($this->manualCheckErrorTransient);
+				} else {
+					$message = sprintf(__('Unknown update checker status "%s"', 'plugin-update-checker'), $status);
+					$noticeClass = 'error notice-error';
+				}
+
+				$message = esc_html($message);
+
+				//Plugins can replace the message with their own, including adding HTML.
+				$message = apply_filters(
+					$this->updateChecker->getUniqueName('manual_check_message'),
+					$message,
+					$status
+				);
+
+				printf(
+					'<div class="notice %s is-dismissible"><p>%s</p>%s</div>',
+					esc_attr($noticeClass),
+					//phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Was escaped above, and plugins can add HTML.
+					$message,
+					//phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Contains HTML. Content should already be escaped.
+					$details
+				);
+			}
+			//phpcs:enable
+		}
+
+		/**
+		 * Format the list of errors that were thrown during an update check.
+		 *
+		 * @param array $errors
+		 * @return string
+		 */
+		protected function formatManualCheckErrors($errors) {
+			if ( empty($errors) ) {
+				return '';
+			}
+			$output = '';
+
+			$showAsList = count($errors) > 1;
+			if ( $showAsList ) {
+				$output .= '<ol>';
+				$formatString = '<li>%1$s <code>%2$s</code></li>';
+			} else {
+				$formatString = '<p>%1$s <code>%2$s</code></p>';
+			}
+			foreach ($errors as $item) {
+				$wpError = $item['error'];
+				/** @var \WP_Error $wpError */
+				$output .= sprintf(
+					$formatString,
+					esc_html($wpError->get_error_message()),
+					esc_html($wpError->get_error_code())
+				);
+			}
+			if ( $showAsList ) {
+				$output .= '</ol>';
+			}
+
+			return $output;
+		}
+
+		public function removeHooks() {
+			remove_action('admin_init', array($this, 'onAdminInit'));
+			remove_filter('plugin_row_meta', array($this, 'addViewDetailsLink'), 10);
+			remove_filter('plugin_row_meta', array($this, 'addCheckForUpdatesLink'), 10);
+			remove_action('all_admin_notices', array($this, 'displayManualCheckResult'));
+		}
+	}
+endif;

lib/plugin-update-checker/Puc/v5p3/Plugin/Update.php

@@ -0,0 +1,116 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Update as BaseUpdate;
+
+if ( !class_exists(Update::class, false) ):
+
+	/**
+	 * A simple container class for holding information about an available update.
+	 *
+	 * @author Janis Elsts
+	 * @copyright 2016
+	 * @access public
+	 */
+	class Update extends BaseUpdate {
+		public $id = 0;
+		public $homepage;
+		public $upgrade_notice;
+		public $tested;
+		public $requires_php = false;
+		public $icons = array();
+		public $filename; //Plugin filename relative to the plugins directory.
+
+		protected static $extraFields = array(
+			'id', 'homepage', 'tested', 'requires_php', 'upgrade_notice', 'icons', 'filename',
+		);
+
+		/**
+		 * Create a new instance of PluginUpdate from its JSON-encoded representation.
+		 *
+		 * @param string $json
+		 * @return self|null
+		 */
+		public static function fromJson($json){
+			//Since update-related information is simply a subset of the full plugin info,
+			//we can parse the update JSON as if it was a plugin info string, then copy over
+			//the parts that we care about.
+			$pluginInfo = PluginInfo::fromJson($json);
+			if ( $pluginInfo !== null ) {
+				return self::fromPluginInfo($pluginInfo);
+			} else {
+				return null;
+			}
+		}
+
+		/**
+		 * Create a new instance of PluginUpdate based on an instance of PluginInfo.
+		 * Basically, this just copies a subset of fields from one object to another.
+		 *
+		 * @param PluginInfo $info
+		 * @return static
+		 */
+		public static function fromPluginInfo($info){
+			return static::fromObject($info);
+		}
+
+		/**
+		 * Create a new instance by copying the necessary fields from another object.
+		 *
+		 * @param \StdClass|PluginInfo|self $object The source object.
+		 * @return self The new copy.
+		 */
+		public static function fromObject($object) {
+			$update = new self();
+			$update->copyFields($object, $update);
+			return $update;
+		}
+
+		/**
+		 * @return string[]
+		 */
+		protected function getFieldNames() {
+			return array_merge(parent::getFieldNames(), self::$extraFields);
+		}
+
+		/**
+		 * Transform the update into the format used by WordPress native plugin API.
+		 *
+		 * @return object
+		 */
+		public function toWpFormat() {
+			$update = parent::toWpFormat();
+
+			$update->id = $this->id;
+			$update->url = $this->homepage;
+			$update->tested = $this->tested;
+			$update->requires_php = $this->requires_php;
+			$update->plugin = $this->filename;
+
+			if ( !empty($this->upgrade_notice) ) {
+				$update->upgrade_notice = $this->upgrade_notice;
+			}
+
+			if ( !empty($this->icons) && is_array($this->icons) ) {
+				//This should be an array with up to 4 keys: 'svg', '1x', '2x' and 'default'.
+				//Docs: https://developer.wordpress.org/plugins/wordpress-org/plugin-assets/#plugin-icons
+				$icons = array_intersect_key(
+					$this->icons,
+					array('svg' => true, '1x' => true, '2x' => true, 'default' => true)
+				);
+				if ( !empty($icons) ) {
+					$update->icons = $icons;
+
+					//It appears that the 'default' icon isn't used anywhere in WordPress 4.9,
+					//but lets set it just in case a future release needs it.
+					if ( !isset($update->icons['default']) ) {
+						$update->icons['default'] = current($update->icons);
+					}
+				}
+			}
+
+			return $update;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Plugin/UpdateChecker.php

@@ -0,0 +1,425 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\InstalledPackage;
+use YahnisElsts\PluginUpdateChecker\v5p3\UpdateChecker as BaseUpdateChecker;
+use YahnisElsts\PluginUpdateChecker\v5p3\Scheduler;
+use YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+if ( !class_exists(UpdateChecker::class, false) ):
+
+	/**
+	 * A custom plugin update checker.
+	 *
+	 * @author Janis Elsts
+	 * @copyright 2018
+	 * @access public
+	 */
+	class UpdateChecker extends BaseUpdateChecker {
+		protected $updateTransient = 'update_plugins';
+		protected $translationType = 'plugin';
+
+		public $pluginAbsolutePath = ''; //Full path of the main plugin file.
+		public $pluginFile = '';  //Plugin filename relative to the plugins directory. Many WP APIs use this to identify plugins.
+		public $muPluginFile = ''; //For MU plugins, the plugin filename relative to the mu-plugins directory.
+
+		/**
+		 * @var Package
+		 */
+		protected $package;
+
+		private $extraUi = null;
+
+		/**
+		 * Class constructor.
+		 *
+		 * @param string $metadataUrl The URL of the plugin's metadata file.
+		 * @param string $pluginFile Fully qualified path to the main plugin file.
+		 * @param string $slug The plugin's 'slug'. If not specified, the filename part of $pluginFile sans '.php' will be used as the slug.
+		 * @param integer $checkPeriod How often to check for updates (in hours). Defaults to checking every 12 hours. Set to 0 to disable automatic update checks.
+		 * @param string $optionName Where to store book-keeping info about update checks. Defaults to 'external_updates-$slug'.
+		 * @param string $muPluginFile Optional. The plugin filename relative to the mu-plugins directory.
+		 */
+		public function __construct($metadataUrl, $pluginFile, $slug = '', $checkPeriod = 12, $optionName = '', $muPluginFile = ''){
+			$this->pluginAbsolutePath = $pluginFile;
+			$this->pluginFile = plugin_basename($this->pluginAbsolutePath);
+			$this->muPluginFile = $muPluginFile;
+
+			//If no slug is specified, use the name of the main plugin file as the slug.
+			//For example, 'my-cool-plugin/cool-plugin.php' becomes 'cool-plugin'.
+			if ( empty($slug) ){
+				$slug = basename($this->pluginFile, '.php');
+			}
+
+			//Plugin slugs must be unique.
+			$slugCheckFilter = 'puc_is_slug_in_use-' . $slug;
+			$slugUsedBy = apply_filters($slugCheckFilter, false);
+			if ( $slugUsedBy ) {
+				$this->triggerError(sprintf(
+					'Plugin slug "%s" is already in use by %s. Slugs must be unique.',
+					$slug,
+					$slugUsedBy
+				), E_USER_ERROR);
+			}
+			add_filter($slugCheckFilter, array($this, 'getAbsolutePath'));
+
+			parent::__construct($metadataUrl, dirname($this->pluginFile), $slug, $checkPeriod, $optionName);
+
+			//Backwards compatibility: If the plugin is a mu-plugin but no $muPluginFile is specified, assume
+			//it's the same as $pluginFile given that it's not in a subdirectory (WP only looks in the base dir).
+			if ( (strpbrk($this->pluginFile, '/\\') === false) && $this->isUnknownMuPlugin() ) {
+				$this->muPluginFile = $this->pluginFile;
+			}
+
+			//To prevent a crash during plugin uninstallation, remove updater hooks when the user removes the plugin.
+			//Details: https://github.com/YahnisElsts/plugin-update-checker/issues/138#issuecomment-335590964
+			add_action('uninstall_' . $this->pluginFile, array($this, 'removeHooks'));
+
+			$this->extraUi = new Ui($this);
+		}
+
+		/**
+		 * Create an instance of the scheduler.
+		 *
+		 * @param int $checkPeriod
+		 * @return Scheduler
+		 */
+		protected function createScheduler($checkPeriod) {
+			$scheduler = new Scheduler($this, $checkPeriod, array('load-plugins.php'));
+			register_deactivation_hook($this->pluginFile, array($scheduler, 'removeUpdaterCron'));
+			return $scheduler;
+		}
+
+		/**
+		 * Install the hooks required to run periodic update checks and inject update info
+		 * into WP data structures.
+		 *
+		 * @return void
+		 */
+		protected function installHooks(){
+			//Override requests for plugin information
+			add_filter('plugins_api', array($this, 'injectInfo'), 20, 3);
+
+			parent::installHooks();
+		}
+
+		/**
+		 * Remove update checker hooks.
+		 *
+		 * The intent is to prevent a fatal error that can happen if the plugin has an uninstall
+		 * hook. During uninstallation, WP includes the main plugin file (which creates a PUC instance),
+		 * the uninstall hook runs, WP deletes the plugin files and then updates some transients.
+		 * If PUC hooks are still around at this time, they could throw an error while trying to
+		 * autoload classes from files that no longer exist.
+		 *
+		 * The "site_transient_{$transient}" filter is the main problem here, but let's also remove
+		 * most other PUC hooks to be safe.
+		 *
+		 * @internal
+		 */
+		public function removeHooks() {
+			parent::removeHooks();
+			$this->extraUi->removeHooks();
+			$this->package->removeHooks();
+
+			remove_filter('plugins_api', array($this, 'injectInfo'), 20);
+		}
+
+		/**
+		 * Retrieve plugin info from the configured API endpoint.
+		 *
+		 * @uses wp_remote_get()
+		 *
+		 * @param array $queryArgs Additional query arguments to append to the request. Optional.
+		 * @return PluginInfo
+		 */
+		public function requestInfo($queryArgs = array()) {
+			list($pluginInfo, $result) = $this->requestMetadata(
+				PluginInfo::class,
+				'request_info',
+				$queryArgs
+			);
+
+			if ( $pluginInfo !== null ) {
+				/** @var PluginInfo $pluginInfo */
+				$pluginInfo->filename = $this->pluginFile;
+				$pluginInfo->slug = $this->slug;
+			}
+
+			$pluginInfo = apply_filters($this->getUniqueName('request_info_result'), $pluginInfo, $result);
+			return $pluginInfo;
+		}
+
+		/**
+		 * Retrieve the latest update (if any) from the configured API endpoint.
+		 *
+		 * @uses UpdateChecker::requestInfo()
+		 *
+		 * @return Update|null An instance of Plugin Update, or NULL when no updates are available.
+		 */
+		public function requestUpdate() {
+			//For the sake of simplicity, this function just calls requestInfo()
+			//and transforms the result accordingly.
+			$pluginInfo = $this->requestInfo(array('checking_for_updates' => '1'));
+			if ( $pluginInfo === null ){
+				return null;
+			}
+			$update = Update::fromPluginInfo($pluginInfo);
+
+			$update = $this->filterUpdateResult($update);
+
+			return $update;
+		}
+
+		/**
+		 * Intercept plugins_api() calls that request information about our plugin and
+		 * use the configured API endpoint to satisfy them.
+		 *
+		 * @see plugins_api()
+		 *
+		 * @param mixed $result
+		 * @param string $action
+		 * @param array|object $args
+		 * @return mixed
+		 */
+		public function injectInfo($result, $action = null, $args = null){
+			$relevant = ($action == 'plugin_information') && isset($args->slug) && (
+					($args->slug == $this->slug) || ($args->slug == dirname($this->pluginFile))
+				);
+			if ( !$relevant ) {
+				return $result;
+			}
+
+			$pluginInfo = $this->requestInfo();
+			$this->fixSupportedWordpressVersion($pluginInfo);
+
+			$pluginInfo = apply_filters($this->getUniqueName('pre_inject_info'), $pluginInfo);
+			if ( $pluginInfo ) {
+				return $pluginInfo->toWpFormat();
+			}
+
+			return $result;
+		}
+
+		protected function shouldShowUpdates() {
+			//No update notifications for mu-plugins unless explicitly enabled. The MU plugin file
+			//is usually different from the main plugin file so the update wouldn't show up properly anyway.
+			return !$this->isUnknownMuPlugin();
+		}
+
+		/**
+		 * @param \stdClass|null $updates
+		 * @param \stdClass $updateToAdd
+		 * @return \stdClass
+		 */
+		protected function addUpdateToList($updates, $updateToAdd) {
+			if ( $this->package->isMuPlugin() ) {
+				//WP does not support automatic update installation for mu-plugins, but we can
+				//still display a notice.
+				$updateToAdd->package = null;
+			}
+			return parent::addUpdateToList($updates, $updateToAdd);
+		}
+
+		/**
+		 * @param \stdClass|null $updates
+		 * @return \stdClass|null
+		 */
+		protected function removeUpdateFromList($updates) {
+			$updates = parent::removeUpdateFromList($updates);
+			if ( !empty($this->muPluginFile) && isset($updates, $updates->response) ) {
+				unset($updates->response[$this->muPluginFile]);
+			}
+			return $updates;
+		}
+
+		/**
+		 * For plugins, the update array is indexed by the plugin filename relative to the "plugins"
+		 * directory. Example: "plugin-name/plugin.php".
+		 *
+		 * @return string
+		 */
+		protected function getUpdateListKey() {
+			if ( $this->package->isMuPlugin() ) {
+				return $this->muPluginFile;
+			}
+			return $this->pluginFile;
+		}
+
+		protected function getNoUpdateItemFields() {
+			return array_merge(
+				parent::getNoUpdateItemFields(),
+				array(
+					'id'            => $this->pluginFile,
+					'slug'          => $this->slug,
+					'plugin'        => $this->pluginFile,
+					'icons'         => array(),
+					'banners'       => array(),
+					'banners_rtl'   => array(),
+					'tested'        => '',
+					'compatibility' => new \stdClass(),
+				)
+			);
+		}
+
+		/**
+		 * Alias for isBeingUpgraded().
+		 *
+		 * @deprecated
+		 * @param \WP_Upgrader|null $upgrader The upgrader that's performing the current update.
+		 * @return bool
+		 */
+		public function isPluginBeingUpgraded($upgrader = null) {
+			return $this->isBeingUpgraded($upgrader);
+		}
+
+		/**
+		 * Is there an update being installed for this plugin, right now?
+		 *
+		 * @param \WP_Upgrader|null $upgrader
+		 * @return bool
+		 */
+		public function isBeingUpgraded($upgrader = null) {
+			return $this->upgraderStatus->isPluginBeingUpgraded($this->pluginFile, $upgrader);
+		}
+
+		/**
+		 * Get the details of the currently available update, if any.
+		 *
+		 * If no updates are available, or if the last known update version is below or equal
+		 * to the currently installed version, this method will return NULL.
+		 *
+		 * Uses cached update data. To retrieve update information straight from
+		 * the metadata URL, call requestUpdate() instead.
+		 *
+		 * @return Update|null
+		 */
+		public function getUpdate() {
+			$update = parent::getUpdate();
+			if ( isset($update) ) {
+				/** @var Update $update */
+				$update->filename = $this->pluginFile;
+			}
+			return $update;
+		}
+
+		/**
+		 * Get the translated plugin title.
+		 *
+		 * @deprecated
+		 * @return string
+		 */
+		public function getPluginTitle() {
+			return $this->package->getPluginTitle();
+		}
+
+		/**
+		 * Check if the current user has the required permissions to install updates.
+		 *
+		 * @return bool
+		 */
+		public function userCanInstallUpdates() {
+			return current_user_can('update_plugins');
+		}
+
+		/**
+		 * Check if the plugin file is inside the mu-plugins directory.
+		 *
+		 * @deprecated
+		 * @return bool
+		 */
+		protected function isMuPlugin() {
+			return $this->package->isMuPlugin();
+		}
+
+		/**
+		 * MU plugins are partially supported, but only when we know which file in mu-plugins
+		 * corresponds to this plugin.
+		 *
+		 * @return bool
+		 */
+		protected function isUnknownMuPlugin() {
+			return empty($this->muPluginFile) && $this->package->isMuPlugin();
+		}
+
+		/**
+		 * Get absolute path to the main plugin file.
+		 *
+		 * @return string
+		 */
+		public function getAbsolutePath() {
+			return $this->pluginAbsolutePath;
+		}
+
+		/**
+		 * Register a callback for filtering query arguments.
+		 *
+		 * The callback function should take one argument - an associative array of query arguments.
+		 * It should return a modified array of query arguments.
+		 *
+		 * @uses add_filter() This method is a convenience wrapper for add_filter().
+		 *
+		 * @param callable $callback
+		 * @return void
+		 */
+		public function addQueryArgFilter($callback){
+			$this->addFilter('request_info_query_args', $callback);
+		}
+
+		/**
+		 * Register a callback for filtering arguments passed to wp_remote_get().
+		 *
+		 * The callback function should take one argument - an associative array of arguments -
+		 * and return a modified array or arguments. See the WP documentation on wp_remote_get()
+		 * for details on what arguments are available and how they work.
+		 *
+		 * @uses add_filter() This method is a convenience wrapper for add_filter().
+		 *
+		 * @param callable $callback
+		 * @return void
+		 */
+		public function addHttpRequestArgFilter($callback) {
+			$this->addFilter('request_info_options', $callback);
+		}
+
+		/**
+		 * Register a callback for filtering the plugin info retrieved from the external API.
+		 *
+		 * The callback function should take two arguments. If the plugin info was retrieved
+		 * successfully, the first argument passed will be an instance of  PluginInfo. Otherwise,
+		 * it will be NULL. The second argument will be the corresponding return value of
+		 * wp_remote_get (see WP docs for details).
+		 *
+		 * The callback function should return a new or modified instance of PluginInfo or NULL.
+		 *
+		 * @uses add_filter() This method is a convenience wrapper for add_filter().
+		 *
+		 * @param callable $callback
+		 * @return void
+		 */
+		public function addResultFilter($callback) {
+			$this->addFilter('request_info_result', $callback, 10, 2);
+		}
+
+		protected function createDebugBarExtension() {
+			return new DebugBar\PluginExtension($this);
+		}
+
+		/**
+		 * Create a package instance that represents this plugin or theme.
+		 *
+		 * @return InstalledPackage
+		 */
+		protected function createInstalledPackage() {
+			return new Package($this->pluginAbsolutePath, $this);
+		}
+
+		/**
+		 * @return Package
+		 */
+		public function getInstalledPackage() {
+			return $this->package;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/PucFactory.php

@@ -0,0 +1,362 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+use YahnisElsts\PluginUpdateChecker\v5p3\Theme;
+use YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !class_exists(PucFactory::class, false) ):
+
+	/**
+	 * A factory that builds update checker instances.
+	 *
+	 * When multiple versions of the same class have been loaded (e.g. PluginUpdateChecker 4.0
+	 * and 4.1), this factory will always use the latest available minor version. Register class
+	 * versions by calling {@link PucFactory::addVersion()}.
+	 *
+	 * At the moment it can only build instances of the UpdateChecker class. Other classes are
+	 * intended mainly for internal use and refer directly to specific implementations.
+	 */
+	class PucFactory {
+		protected static $classVersions = array();
+		protected static $sorted = false;
+
+		protected static $myMajorVersion = '';
+		protected static $latestCompatibleVersion = '';
+
+		/**
+		 * A wrapper method for buildUpdateChecker() that reads the metadata URL from the plugin or theme header.
+		 *
+		 * @param string $fullPath Full path to the main plugin file or the theme's style.css.
+		 * @param array $args Optional arguments. Keys should match the argument names of the buildUpdateChecker() method.
+		 * @return Plugin\UpdateChecker|Theme\UpdateChecker|Vcs\BaseChecker
+		 */
+		public static function buildFromHeader($fullPath, $args = array()) {
+			$fullPath = self::normalizePath($fullPath);
+
+			//Set up defaults.
+			$defaults = array(
+				'metadataUrl'  => '',
+				'slug'         => '',
+				'checkPeriod'  => 12,
+				'optionName'   => '',
+				'muPluginFile' => '',
+			);
+			$args = array_merge($defaults, array_intersect_key($args, $defaults));
+			extract($args, EXTR_SKIP);
+
+			//Check for the service URI
+			if ( empty($metadataUrl) ) {
+				$metadataUrl = self::getServiceURI($fullPath);
+			}
+
+			return self::buildUpdateChecker($metadataUrl, $fullPath, $slug, $checkPeriod, $optionName, $muPluginFile);
+		}
+
+		/**
+		 * Create a new instance of the update checker.
+		 *
+		 * This method automatically detects if you're using it for a plugin or a theme and chooses
+		 * the appropriate implementation for your update source (JSON file, GitHub, BitBucket, etc).
+		 *
+		 * @see UpdateChecker::__construct
+		 *
+		 * @param string $metadataUrl The URL of the metadata file, a GitHub repository, or another supported update source.
+		 * @param string $fullPath Full path to the main plugin file or to the theme directory.
+		 * @param string $slug Custom slug. Defaults to the name of the main plugin file or the theme directory.
+		 * @param int $checkPeriod How often to check for updates (in hours).
+		 * @param string $optionName Where to store bookkeeping info about update checks.
+		 * @param string $muPluginFile The plugin filename relative to the mu-plugins directory.
+		 * @return Plugin\UpdateChecker|Theme\UpdateChecker|Vcs\BaseChecker
+		 */
+		public static function buildUpdateChecker($metadataUrl, $fullPath, $slug = '', $checkPeriod = 12, $optionName = '', $muPluginFile = '') {
+			$fullPath = self::normalizePath($fullPath);
+			$id = null;
+
+			//Plugin or theme?
+			$themeDirectory = self::getThemeDirectoryName($fullPath);
+			if ( self::isPluginFile($fullPath) ) {
+				$type = 'Plugin';
+				$id = $fullPath;
+			} else if ( $themeDirectory !== null ) {
+				$type = 'Theme';
+				$id = $themeDirectory;
+			} else {
+				throw new \RuntimeException(sprintf(
+					'The update checker cannot determine if "%s" is a plugin or a theme. ' .
+					'This is a bug. Please contact the PUC developer.',
+					htmlentities($fullPath)
+				));
+			}
+
+			//Which hosting service does the URL point to?
+			$service = self::getVcsService($metadataUrl);
+
+			$apiClass = null;
+			if ( empty($service) ) {
+				//The default is to get update information from a remote JSON file.
+				$checkerClass = $type . '\\UpdateChecker';
+			} else {
+				//You can also use a VCS repository like GitHub.
+				$checkerClass = 'Vcs\\' . $type . 'UpdateChecker';
+				$apiClass = $service . 'Api';
+			}
+
+			$checkerClass = self::getCompatibleClassVersion($checkerClass);
+			if ( $checkerClass === null ) {
+				//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
+				trigger_error(
+					esc_html(sprintf(
+						'PUC %s does not support updates for %ss %s',
+						self::$latestCompatibleVersion,
+						strtolower($type),
+						$service ? ('hosted on ' . $service) : 'using JSON metadata'
+					)),
+					E_USER_ERROR
+				);
+			}
+
+			if ( !isset($apiClass) ) {
+				//Plain old update checker.
+				return new $checkerClass($metadataUrl, $id, $slug, $checkPeriod, $optionName, $muPluginFile);
+			} else {
+				//VCS checker + an API client.
+				$apiClass = self::getCompatibleClassVersion($apiClass);
+				if ( $apiClass === null ) {
+					//phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
+					trigger_error(esc_html(sprintf(
+						'PUC %s does not support %s',
+						self::$latestCompatibleVersion,
+						$service
+					)), E_USER_ERROR);
+				}
+
+				return new $checkerClass(
+					new $apiClass($metadataUrl),
+					$id,
+					$slug,
+					$checkPeriod,
+					$optionName,
+					$muPluginFile
+				);
+			}
+		}
+
+		/**
+		 *
+		 * Normalize a filesystem path. Introduced in WP 3.9.
+		 * Copying here allows use of the class on earlier versions.
+		 * This version adapted from WP 4.8.2 (unchanged since 4.5.3)
+		 *
+		 * @param string $path Path to normalize.
+		 * @return string Normalized path.
+		 */
+		public static function normalizePath($path) {
+			if ( function_exists('wp_normalize_path') ) {
+				return wp_normalize_path($path);
+			}
+			$path = str_replace('\\', '/', $path);
+			$path = preg_replace('|(?<=.)/+|', '/', $path);
+			if ( substr($path, 1, 1) === ':' ) {
+				$path = ucfirst($path);
+			}
+			return $path;
+		}
+
+		/**
+		 * Check if the path points to a plugin file.
+		 *
+		 * @param string $absolutePath Normalized path.
+		 * @return bool
+		 */
+		protected static function isPluginFile($absolutePath) {
+			//Is the file inside the "plugins" or "mu-plugins" directory?
+			$pluginDir = self::normalizePath(WP_PLUGIN_DIR);
+			$muPluginDir = self::normalizePath(WPMU_PLUGIN_DIR);
+			if ( (strpos($absolutePath, $pluginDir) === 0) || (strpos($absolutePath, $muPluginDir) === 0) ) {
+				return true;
+			}
+
+			//Is it a file at all? Caution: is_file() can fail if the parent dir. doesn't have the +x permission set.
+			if ( !is_file($absolutePath) ) {
+				return false;
+			}
+
+			//Does it have a valid plugin header?
+			//This is a last-ditch check for plugins symlinked from outside the WP root.
+			if ( function_exists('get_file_data') ) {
+				$headers = get_file_data($absolutePath, array('Name' => 'Plugin Name'), 'plugin');
+				return !empty($headers['Name']);
+			}
+
+			return false;
+		}
+
+		/**
+		 * Get the name of the theme's directory from a full path to a file inside that directory.
+		 * E.g. "/abc/public_html/wp-content/themes/foo/whatever.php" => "foo".
+		 *
+		 * Note that subdirectories are currently not supported. For example,
+		 * "/xyz/wp-content/themes/my-theme/includes/whatever.php" => NULL.
+		 *
+		 * @param string $absolutePath Normalized path.
+		 * @return string|null Directory name, or NULL if the path doesn't point to a theme.
+		 */
+		protected static function getThemeDirectoryName($absolutePath) {
+			if ( is_file($absolutePath) ) {
+				$absolutePath = dirname($absolutePath);
+			}
+
+			if ( file_exists($absolutePath . '/style.css') ) {
+				return basename($absolutePath);
+			}
+			return null;
+		}
+
+		/**
+		 * Get the service URI from the file header.
+		 *
+		 * @param string $fullPath
+		 * @return string
+		 */
+		private static function getServiceURI($fullPath) {
+			//Look for the URI
+			if ( is_readable($fullPath) ) {
+				$seek = array(
+					'github' => 'GitHub URI',
+					'gitlab' => 'GitLab URI',
+					'bucket' => 'BitBucket URI',
+				);
+				$seek = apply_filters('puc_get_source_uri', $seek);
+				$data = get_file_data($fullPath, $seek);
+				foreach ($data as $key => $uri) {
+					if ( $uri ) {
+						return $uri;
+					}
+				}
+			}
+
+			//URI was not found so throw an error.
+			throw new \RuntimeException(
+				sprintf('Unable to locate URI in header of "%s"', htmlentities($fullPath))
+			);
+		}
+
+		/**
+		 * Get the name of the hosting service that the URL points to.
+		 *
+		 * @param string $metadataUrl
+		 * @return string|null
+		 */
+		private static function getVcsService($metadataUrl) {
+			$service = null;
+
+			//Which hosting service does the URL point to?
+			$host = (string)(wp_parse_url($metadataUrl, PHP_URL_HOST));
+			$path = (string)(wp_parse_url($metadataUrl, PHP_URL_PATH));
+
+			//Check if the path looks like "/user-name/repository".
+			//For GitLab.com it can also be "/user/group1/group2/.../repository".
+			$repoRegex = '@^/?([^/]+?)/([^/#?&]+?)/?$@';
+			if ( $host === 'gitlab.com' ) {
+				$repoRegex = '@^/?(?:[^/#?&]++/){1,20}(?:[^/#?&]++)/?$@';
+			}
+			if ( preg_match($repoRegex, $path) ) {
+				$knownServices = array(
+					'github.com' => 'GitHub',
+					'bitbucket.org' => 'BitBucket',
+					'gitlab.com' => 'GitLab',
+				);
+				if ( isset($knownServices[$host]) ) {
+					$service = $knownServices[$host];
+				}
+			}
+
+			return apply_filters('puc_get_vcs_service', $service, $host, $path, $metadataUrl);
+		}
+
+		/**
+		 * Get the latest version of the specified class that has the same major version number
+		 * as this factory class.
+		 *
+		 * @param string $class Partial class name.
+		 * @return string|null Full class name.
+		 */
+		protected static function getCompatibleClassVersion($class) {
+			if ( isset(self::$classVersions[$class][self::$latestCompatibleVersion]) ) {
+				return self::$classVersions[$class][self::$latestCompatibleVersion];
+			}
+			return null;
+		}
+
+		/**
+		 * Get the specific class name for the latest available version of a class.
+		 *
+		 * @param string $class
+		 * @return null|string
+		 */
+		public static function getLatestClassVersion($class) {
+			if ( !self::$sorted ) {
+				self::sortVersions();
+			}
+
+			if ( isset(self::$classVersions[$class]) ) {
+				return reset(self::$classVersions[$class]);
+			} else {
+				return null;
+			}
+		}
+
+		/**
+		 * Sort available class versions in descending order (i.e. newest first).
+		 */
+		protected static function sortVersions() {
+			foreach ( self::$classVersions as $class => $versions ) {
+				uksort($versions, array(__CLASS__, 'compareVersions'));
+				self::$classVersions[$class] = $versions;
+			}
+			self::$sorted = true;
+		}
+
+		protected static function compareVersions($a, $b) {
+			return -version_compare($a, $b);
+		}
+
+		/**
+		 * Register a version of a class.
+		 *
+		 * @access private This method is only for internal use by the library.
+		 *
+		 * @param string $generalClass Class name without version numbers, e.g. 'PluginUpdateChecker'.
+		 * @param string $versionedClass Actual class name, e.g. 'PluginUpdateChecker_1_2'.
+		 * @param string $version Version number, e.g. '1.2'.
+		 */
+		public static function addVersion($generalClass, $versionedClass, $version) {
+			if ( empty(self::$myMajorVersion) ) {
+				$lastNamespaceSegment = substr(__NAMESPACE__, strrpos(__NAMESPACE__, '\\') + 1);
+				self::$myMajorVersion = substr(ltrim($lastNamespaceSegment, 'v'), 0, 1);
+			}
+
+			//Store the greatest version number that matches our major version.
+			$components = explode('.', $version);
+			if ( $components[0] === self::$myMajorVersion ) {
+
+				if (
+					empty(self::$latestCompatibleVersion)
+					|| version_compare($version, self::$latestCompatibleVersion, '>')
+				) {
+					self::$latestCompatibleVersion = $version;
+				}
+
+			}
+
+			if ( !isset(self::$classVersions[$generalClass]) ) {
+				self::$classVersions[$generalClass] = array();
+			}
+			self::$classVersions[$generalClass][$version] = $versionedClass;
+			self::$sorted = false;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Scheduler.php

@@ -0,0 +1,278 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(Scheduler::class, false) ):
+
+	/**
+	 * The scheduler decides when and how often to check for updates.
+	 * It calls @see UpdateChecker::checkForUpdates() to perform the actual checks.
+	 */
+	class Scheduler {
+		public $checkPeriod = 12; //How often to check for updates (in hours).
+		public $throttleRedundantChecks = false; //Check less often if we already know that an update is available.
+		public $throttledCheckPeriod = 72;
+
+		protected $hourlyCheckHooks = array('load-update.php');
+
+		/**
+		 * @var UpdateChecker
+		 */
+		protected $updateChecker;
+
+		private $cronHook = null;
+
+		/**
+		 * Scheduler constructor.
+		 *
+		 * @param UpdateChecker $updateChecker
+		 * @param int $checkPeriod How often to check for updates (in hours).
+		 * @param array $hourlyHooks
+		 */
+		public function __construct($updateChecker, $checkPeriod, $hourlyHooks = array('load-plugins.php')) {
+			$this->updateChecker = $updateChecker;
+			$this->checkPeriod = $checkPeriod;
+
+			//Set up the periodic update checks
+			$this->cronHook = $this->updateChecker->getUniqueName('cron_check_updates');
+			if ( $this->checkPeriod > 0 ){
+
+				//Trigger the check via Cron.
+				//Try to use one of the default schedules if possible as it's less likely to conflict
+				//with other plugins and their custom schedules.
+				$defaultSchedules = array(
+					1  => 'hourly',
+					12 => 'twicedaily',
+					24 => 'daily',
+				);
+				if ( array_key_exists($this->checkPeriod, $defaultSchedules) ) {
+					$scheduleName = $defaultSchedules[$this->checkPeriod];
+				} else {
+					//Use a custom cron schedule.
+					$scheduleName = 'every' . $this->checkPeriod . 'hours';
+					//phpcs:ignore WordPress.WP.CronInterval.ChangeDetected -- WPCS fails to parse the callback.
+					add_filter('cron_schedules', array($this, '_addCustomSchedule'));
+				}
+
+				if ( !wp_next_scheduled($this->cronHook) && !defined('WP_INSTALLING') ) {
+					//Randomly offset the schedule to help prevent update server traffic spikes. Without this
+					//most checks may happen during times of day when people are most likely to install new plugins.
+					$upperLimit = max($this->checkPeriod * 3600 - 15 * 60, 1);
+					if ( function_exists('wp_rand') ) {
+						$randomOffset = wp_rand(0, $upperLimit);
+					} else {
+						//This constructor may be called before wp_rand() is available.
+						//phpcs:ignore WordPress.WP.AlternativeFunctions.rand_rand
+						$randomOffset = rand(0, $upperLimit);
+					}
+					$firstCheckTime = time() - $randomOffset;
+					$firstCheckTime = apply_filters(
+						$this->updateChecker->getUniqueName('first_check_time'),
+						$firstCheckTime
+					);
+					wp_schedule_event($firstCheckTime, $scheduleName, $this->cronHook);
+				}
+				add_action($this->cronHook, array($this, 'maybeCheckForUpdates'));
+
+				//In case Cron is disabled or unreliable, we also manually trigger
+				//the periodic checks while the user is browsing the Dashboard.
+				add_action( 'admin_init', array($this, 'maybeCheckForUpdates') );
+
+				//Like WordPress itself, we check more often on certain pages.
+				/** @see wp_update_plugins */
+				add_action('load-update-core.php', array($this, 'maybeCheckForUpdates'));
+				//phpcs:ignore Squiz.PHP.CommentedOutCode.Found -- Not actually code, just file names.
+				//"load-update.php" and "load-plugins.php" or "load-themes.php".
+				$this->hourlyCheckHooks = array_merge($this->hourlyCheckHooks, $hourlyHooks);
+				foreach($this->hourlyCheckHooks as $hook) {
+					add_action($hook, array($this, 'maybeCheckForUpdates'));
+				}
+				//This hook fires after a bulk update is complete.
+				add_action('upgrader_process_complete', array($this, 'upgraderProcessComplete'), 11, 2);
+
+			} else {
+				//Periodic checks are disabled.
+				wp_clear_scheduled_hook($this->cronHook);
+			}
+		}
+
+		/**
+		 * Runs upon the WP action upgrader_process_complete.
+		 *
+		 * We look at the parameters to decide whether to call maybeCheckForUpdates() or not.
+		 * We also check if the update checker has been removed by the update.
+		 *
+		 * @param \WP_Upgrader $upgrader  WP_Upgrader instance
+		 * @param array $upgradeInfo extra information about the upgrade
+		 */
+		public function upgraderProcessComplete(
+			/** @noinspection PhpUnusedParameterInspection */
+			$upgrader, $upgradeInfo
+		) {
+			//Cancel all further actions if the current version of PUC has been deleted or overwritten
+			//by a different version during the upgrade. If we try to do anything more in that situation,
+			//we could trigger a fatal error by trying to autoload a deleted class.
+			clearstatcache();
+			if ( !file_exists(__FILE__) ) {
+				$this->removeHooks();
+				$this->updateChecker->removeHooks();
+				return;
+			}
+
+			//Sanity check and limitation to relevant types.
+			if (
+				!is_array($upgradeInfo) || !isset($upgradeInfo['type'], $upgradeInfo['action'])
+				|| 'update' !== $upgradeInfo['action'] || !in_array($upgradeInfo['type'], array('plugin', 'theme'))
+			) {
+				return;
+			}
+
+			//Filter out notifications of upgrades that should have no bearing upon whether or not our
+			//current info is up-to-date.
+			if ( is_a($this->updateChecker, Theme\UpdateChecker::class) ) {
+				if ( 'theme' !== $upgradeInfo['type'] || !isset($upgradeInfo['themes']) ) {
+					return;
+				}
+
+				//Letting too many things going through for checks is not a real problem, so we compare widely.
+				if ( !in_array(
+					strtolower($this->updateChecker->directoryName),
+					array_map('strtolower', $upgradeInfo['themes'])
+				) ) {
+					return;
+				}
+			}
+
+			if ( is_a($this->updateChecker, Plugin\UpdateChecker::class) ) {
+				if ( 'plugin' !== $upgradeInfo['type'] || !isset($upgradeInfo['plugins']) ) {
+					return;
+				}
+
+				//Themes pass in directory names in the information array, but plugins use the relative plugin path.
+				if ( !in_array(
+					strtolower($this->updateChecker->directoryName),
+					array_map('dirname', array_map('strtolower', $upgradeInfo['plugins']))
+				) ) {
+					return;
+				}
+			}
+
+			$this->maybeCheckForUpdates();
+		}
+
+		/**
+		 * Check for updates if the configured check interval has already elapsed.
+		 * Will use a shorter check interval on certain admin pages like "Dashboard -> Updates" or when doing cron.
+		 *
+		 * You can override the default behaviour by using the "puc_check_now-$slug" filter.
+		 * The filter callback will be passed three parameters:
+		 *     - Current decision. TRUE = check updates now, FALSE = don't check now.
+		 *     - Last check time as a Unix timestamp.
+		 *     - Configured check period in hours.
+		 * Return TRUE to check for updates immediately, or FALSE to cancel.
+		 *
+		 * This method is declared public because it's a hook callback. Calling it directly is not recommended.
+		 */
+		public function maybeCheckForUpdates() {
+			if ( empty($this->checkPeriod) ){
+				return;
+			}
+
+			$state = $this->updateChecker->getUpdateState();
+			$shouldCheck = ($state->timeSinceLastCheck() >= $this->getEffectiveCheckPeriod());
+
+			//Let plugin authors substitute their own algorithm.
+			$shouldCheck = apply_filters(
+				$this->updateChecker->getUniqueName('check_now'),
+				$shouldCheck,
+				$state->getLastCheck(),
+				$this->checkPeriod
+			);
+
+			if ( $shouldCheck ) {
+				$this->updateChecker->checkForUpdates();
+			}
+		}
+
+		/**
+		 * Calculate the actual check period based on the current status and environment.
+		 *
+		 * @return int Check period in seconds.
+		 */
+		protected function getEffectiveCheckPeriod() {
+			$currentFilter = current_filter();
+			if ( in_array($currentFilter, array('load-update-core.php', 'upgrader_process_complete')) ) {
+				//Check more often when the user visits "Dashboard -> Updates" or does a bulk update.
+				$period = 60;
+			} else if ( in_array($currentFilter, $this->hourlyCheckHooks) ) {
+				//Also check more often on /wp-admin/update.php and the "Plugins" or "Themes" page.
+				$period = 3600;
+			} else if ( $this->throttleRedundantChecks && ($this->updateChecker->getUpdate() !== null) ) {
+				//Check less frequently if it's already known that an update is available.
+				$period = $this->throttledCheckPeriod * 3600;
+			} else if ( defined('DOING_CRON') && constant('DOING_CRON') ) {
+				//WordPress cron schedules are not exact, so let's do an update check even
+				//if slightly less than $checkPeriod hours have elapsed since the last check.
+				$cronFuzziness = 20 * 60;
+				$period = $this->checkPeriod * 3600 - $cronFuzziness;
+			} else {
+				$period = $this->checkPeriod * 3600;
+			}
+
+			return $period;
+		}
+
+		/**
+		 * Add our custom schedule to the array of Cron schedules used by WP.
+		 *
+		 * @param array $schedules
+		 * @return array
+		 */
+		public function _addCustomSchedule($schedules) {
+			if ( $this->checkPeriod && ($this->checkPeriod > 0) ){
+				$scheduleName = 'every' . $this->checkPeriod . 'hours';
+				$schedules[$scheduleName] = array(
+					'interval' => $this->checkPeriod * 3600,
+					'display' => sprintf('Every %d hours', $this->checkPeriod),
+				);
+			}
+			return $schedules;
+		}
+
+		/**
+		 * Remove the scheduled cron event that the library uses to check for updates.
+		 *
+		 * @return void
+		 */
+		public function removeUpdaterCron() {
+			wp_clear_scheduled_hook($this->cronHook);
+		}
+
+		/**
+		 * Get the name of the update checker's WP-cron hook. Mostly useful for debugging.
+		 *
+		 * @return string
+		 */
+		public function getCronHookName() {
+			return $this->cronHook;
+		}
+
+		/**
+		 * Remove most hooks added by the scheduler.
+		 */
+		public function removeHooks() {
+			remove_filter('cron_schedules', array($this, '_addCustomSchedule'));
+			remove_action('admin_init', array($this, 'maybeCheckForUpdates'));
+			remove_action('load-update-core.php', array($this, 'maybeCheckForUpdates'));
+
+			if ( $this->cronHook !== null ) {
+				remove_action($this->cronHook, array($this, 'maybeCheckForUpdates'));
+			}
+			if ( !empty($this->hourlyCheckHooks) ) {
+				foreach ($this->hourlyCheckHooks as $hook) {
+					remove_action($hook, array($this, 'maybeCheckForUpdates'));
+				}
+			}
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/StateStore.php

@@ -0,0 +1,209 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(StateStore::class, false) ):
+
+	class StateStore {
+		/**
+		 * @var int Last update check timestamp.
+		 */
+		protected $lastCheck = 0;
+
+		/**
+		 * @var string Version number.
+		 */
+		protected $checkedVersion = '';
+
+		/**
+		 * @var Update|null Cached update.
+		 */
+		protected $update = null;
+
+		/**
+		 * @var string Site option name.
+		 */
+		private $optionName = '';
+
+		/**
+		 * @var bool Whether we've already tried to load the state from the database.
+		 */
+		private $isLoaded = false;
+
+		public function __construct($optionName) {
+			$this->optionName = $optionName;
+		}
+
+		/**
+		 * Get time elapsed since the last update check.
+		 *
+		 * If there are no recorded update checks, this method returns a large arbitrary number
+		 * (i.e. time since the Unix epoch).
+		 *
+		 * @return int Elapsed time in seconds.
+		 */
+		public function timeSinceLastCheck() {
+			$this->lazyLoad();
+			return time() - $this->lastCheck;
+		}
+
+		/**
+		 * @return int
+		 */
+		public function getLastCheck() {
+			$this->lazyLoad();
+			return $this->lastCheck;
+		}
+
+		/**
+		 * Set the time of the last update check to the current timestamp.
+		 *
+		 * @return $this
+		 */
+		public function setLastCheckToNow() {
+			$this->lazyLoad();
+			$this->lastCheck = time();
+			return $this;
+		}
+
+		/**
+		 * @return null|Update
+		 */
+		public function getUpdate() {
+			$this->lazyLoad();
+			return $this->update;
+		}
+
+		/**
+		 * @param Update|null $update
+		 * @return $this
+		 */
+		public function setUpdate(Update $update = null) {
+			$this->lazyLoad();
+			$this->update = $update;
+			return $this;
+		}
+
+		/**
+		 * @return string
+		 */
+		public function getCheckedVersion() {
+			$this->lazyLoad();
+			return $this->checkedVersion;
+		}
+
+		/**
+		 * @param string $version
+		 * @return $this
+		 */
+		public function setCheckedVersion($version) {
+			$this->lazyLoad();
+			$this->checkedVersion = strval($version);
+			return $this;
+		}
+
+		/**
+		 * Get translation updates.
+		 *
+		 * @return array
+		 */
+		public function getTranslations() {
+			$this->lazyLoad();
+			if ( isset($this->update, $this->update->translations) ) {
+				return $this->update->translations;
+			}
+			return array();
+		}
+
+		/**
+		 * Set translation updates.
+		 *
+		 * @param array $translationUpdates
+		 */
+		public function setTranslations($translationUpdates) {
+			$this->lazyLoad();
+			if ( isset($this->update) ) {
+				$this->update->translations = $translationUpdates;
+				$this->save();
+			}
+		}
+
+		public function save() {
+			$state = new \stdClass();
+
+			$state->lastCheck = $this->lastCheck;
+			$state->checkedVersion = $this->checkedVersion;
+
+			if ( isset($this->update)) {
+				$state->update = $this->update->toStdClass();
+
+				$updateClass = get_class($this->update);
+				$state->updateClass = $updateClass;
+				$prefix = $this->getLibPrefix();
+				if ( Utils::startsWith($updateClass, $prefix) ) {
+					$state->updateBaseClass = substr($updateClass, strlen($prefix));
+				}
+			}
+
+			update_site_option($this->optionName, $state);
+			$this->isLoaded = true;
+		}
+
+		/**
+		 * @return $this
+		 */
+		public function lazyLoad() {
+			if ( !$this->isLoaded ) {
+				$this->load();
+			}
+			return $this;
+		}
+
+		protected function load() {
+			$this->isLoaded = true;
+
+			$state = get_site_option($this->optionName, null);
+
+			if ( !is_object($state) ) {
+				$this->lastCheck = 0;
+				$this->checkedVersion = '';
+				$this->update = null;
+				return;
+			}
+
+			$this->lastCheck = intval(Utils::get($state, 'lastCheck', 0));
+			$this->checkedVersion = Utils::get($state, 'checkedVersion', '');
+			$this->update = null;
+
+			if ( isset($state->update) ) {
+				//This mess is due to the fact that the want the update class from this version
+				//of the library, not the version that saved the update.
+
+				$updateClass = null;
+				if ( isset($state->updateBaseClass) ) {
+					$updateClass = $this->getLibPrefix() . $state->updateBaseClass;
+				} else if ( isset($state->updateClass) ) {
+					$updateClass = $state->updateClass;
+				}
+
+				$factory = array($updateClass, 'fromObject');
+				if ( ($updateClass !== null) && is_callable($factory) ) {
+					$this->update = call_user_func($factory, $state->update);
+				}
+			}
+		}
+
+		public function delete() {
+			delete_site_option($this->optionName);
+
+			$this->lastCheck = 0;
+			$this->checkedVersion = '';
+			$this->update = null;
+		}
+
+		private function getLibPrefix() {
+			//This assumes that the current class is at the top of the versioned namespace.
+			return __NAMESPACE__ . '\\';
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Theme/Package.php

@@ -0,0 +1,69 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Theme;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\InstalledPackage;
+
+if ( !class_exists(Package::class, false) ):
+
+	class Package extends InstalledPackage {
+		/**
+		 * @var string Theme directory name.
+		 */
+		protected $stylesheet;
+
+		/**
+		 * @var \WP_Theme Theme object.
+		 */
+		protected $theme;
+
+		public function __construct($stylesheet, $updateChecker) {
+			$this->stylesheet = $stylesheet;
+			$this->theme = wp_get_theme($this->stylesheet);
+
+			parent::__construct($updateChecker);
+		}
+
+		public function getInstalledVersion() {
+			return $this->theme->get('Version');
+		}
+
+		public function getAbsoluteDirectoryPath() {
+			if ( method_exists($this->theme, 'get_stylesheet_directory') ) {
+				return $this->theme->get_stylesheet_directory(); //Available since WP 3.4.
+			}
+			return get_theme_root($this->stylesheet) . '/' . $this->stylesheet;
+		}
+
+		/**
+		 * Get the value of a specific plugin or theme header.
+		 *
+		 * @param string $headerName
+		 * @param string $defaultValue
+		 * @return string Either the value of the header, or $defaultValue if the header doesn't exist or is empty.
+		 */
+		public function getHeaderValue($headerName, $defaultValue = '') {
+			$value = $this->theme->get($headerName);
+			if ( ($headerName === false) || ($headerName === '') ) {
+				return $defaultValue;
+			}
+			return $value;
+		}
+
+		protected function getHeaderNames() {
+			return array(
+				'Name'        => 'Theme Name',
+				'ThemeURI'    => 'Theme URI',
+				'Description' => 'Description',
+				'Author'      => 'Author',
+				'AuthorURI'   => 'Author URI',
+				'Version'     => 'Version',
+				'Template'    => 'Template',
+				'Status'      => 'Status',
+				'Tags'        => 'Tags',
+				'TextDomain'  => 'Text Domain',
+				'DomainPath'  => 'Domain Path',
+			);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Theme/Update.php

@@ -0,0 +1,88 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Theme;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Update as BaseUpdate;
+
+if ( !class_exists(Update::class, false) ):
+
+	class Update extends BaseUpdate {
+		public $details_url = '';
+
+		protected static $extraFields = array('details_url');
+
+		/**
+		 * Transform the metadata into the format used by WordPress core.
+		 * Note the inconsistency: WP stores plugin updates as objects and theme updates as arrays.
+		 *
+		 * @return array
+		 */
+		public function toWpFormat() {
+			$update = array(
+				'theme' => $this->slug,
+				'new_version' => $this->version,
+				'url' => $this->details_url,
+			);
+
+			if ( !empty($this->download_url) ) {
+				$update['package'] = $this->download_url;
+			}
+
+			return $update;
+		}
+
+		/**
+		 * Create a new instance of Theme_Update from its JSON-encoded representation.
+		 *
+		 * @param string $json Valid JSON string representing a theme information object.
+		 * @return self New instance of ThemeUpdate, or NULL on error.
+		 */
+		public static function fromJson($json) {
+			$instance = new self();
+			if ( !parent::createFromJson($json, $instance) ) {
+				return null;
+			}
+			return $instance;
+		}
+
+		/**
+		 * Create a new instance by copying the necessary fields from another object.
+		 *
+		 * @param \StdClass|self $object The source object.
+		 * @return self The new copy.
+		 */
+		public static function fromObject($object) {
+			$update = new self();
+			$update->copyFields($object, $update);
+			return $update;
+		}
+
+		/**
+		 * Basic validation.
+		 *
+		 * @param \StdClass $apiResponse
+		 * @return bool|\WP_Error
+		 */
+		protected function validateMetadata($apiResponse) {
+			$required = array('version', 'details_url');
+			foreach($required as $key) {
+				if ( !isset($apiResponse->$key) || empty($apiResponse->$key) ) {
+					return new \WP_Error(
+						'tuc-invalid-metadata',
+						sprintf('The theme metadata is missing the required "%s" key.', $key)
+					);
+				}
+			}
+			return true;
+		}
+
+		protected function getFieldNames() {
+			return array_merge(parent::getFieldNames(), self::$extraFields);
+		}
+
+		protected function getPrefixedFilter($tag) {
+			return parent::getPrefixedFilter($tag) . '_theme';
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Theme/UpdateChecker.php

@@ -0,0 +1,159 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Theme;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\UpdateChecker as BaseUpdateChecker;
+use YahnisElsts\PluginUpdateChecker\v5p3\InstalledPackage;
+use YahnisElsts\PluginUpdateChecker\v5p3\Scheduler;
+use YahnisElsts\PluginUpdateChecker\v5p3\DebugBar;
+
+if ( !class_exists(UpdateChecker::class, false) ):
+
+	class UpdateChecker extends BaseUpdateChecker {
+		protected $filterSuffix = 'theme';
+		protected $updateTransient = 'update_themes';
+		protected $translationType = 'theme';
+
+		/**
+		 * @var string Theme directory name.
+		 */
+		protected $stylesheet;
+
+		public function __construct($metadataUrl, $stylesheet = null, $customSlug = null, $checkPeriod = 12, $optionName = '') {
+			if ( $stylesheet === null ) {
+				$stylesheet = get_stylesheet();
+			}
+			$this->stylesheet = $stylesheet;
+
+			parent::__construct(
+				$metadataUrl,
+				$stylesheet,
+				$customSlug ? $customSlug : $stylesheet,
+				$checkPeriod,
+				$optionName
+			);
+		}
+
+		/**
+		 * For themes, the update array is indexed by theme directory name.
+		 *
+		 * @return string
+		 */
+		protected function getUpdateListKey() {
+			return $this->directoryName;
+		}
+
+		/**
+		 * Retrieve the latest update (if any) from the configured API endpoint.
+		 *
+		 * @return Update|null An instance of Update, or NULL when no updates are available.
+		 */
+		public function requestUpdate() {
+			list($themeUpdate, $result) = $this->requestMetadata(Update::class, 'request_update');
+
+			if ( $themeUpdate !== null ) {
+				/** @var Update $themeUpdate */
+				$themeUpdate->slug = $this->slug;
+			}
+
+			$themeUpdate = $this->filterUpdateResult($themeUpdate, $result);
+			return $themeUpdate;
+		}
+
+		protected function getNoUpdateItemFields() {
+			return array_merge(
+				parent::getNoUpdateItemFields(),
+				array(
+					'theme'        => $this->directoryName,
+					'requires'     => '',
+				)
+			);
+		}
+
+		public function userCanInstallUpdates() {
+			return current_user_can('update_themes');
+		}
+
+		/**
+		 * Create an instance of the scheduler.
+		 *
+		 * @param int $checkPeriod
+		 * @return Scheduler
+		 */
+		protected function createScheduler($checkPeriod) {
+			return new Scheduler($this, $checkPeriod, array('load-themes.php'));
+		}
+
+		/**
+		 * Is there an update being installed right now for this theme?
+		 *
+		 * @param \WP_Upgrader|null $upgrader The upgrader that's performing the current update.
+		 * @return bool
+		 */
+		public function isBeingUpgraded($upgrader = null) {
+			return $this->upgraderStatus->isThemeBeingUpgraded($this->stylesheet, $upgrader);
+		}
+
+		protected function createDebugBarExtension() {
+			return new DebugBar\Extension($this, DebugBar\ThemePanel::class);
+		}
+
+		/**
+		 * Register a callback for filtering query arguments.
+		 *
+		 * The callback function should take one argument - an associative array of query arguments.
+		 * It should return a modified array of query arguments.
+		 *
+		 * @param callable $callback
+		 * @return void
+		 */
+		public function addQueryArgFilter($callback){
+			$this->addFilter('request_update_query_args', $callback);
+		}
+
+		/**
+		 * Register a callback for filtering arguments passed to wp_remote_get().
+		 *
+		 * The callback function should take one argument - an associative array of arguments -
+		 * and return a modified array or arguments. See the WP documentation on wp_remote_get()
+		 * for details on what arguments are available and how they work.
+		 *
+		 * @uses add_filter() This method is a convenience wrapper for add_filter().
+		 *
+		 * @param callable $callback
+		 * @return void
+		 */
+		public function addHttpRequestArgFilter($callback) {
+			$this->addFilter('request_update_options', $callback);
+		}
+
+		/**
+		 * Register a callback for filtering theme updates retrieved from the external API.
+		 *
+		 * The callback function should take two arguments. If the theme update was retrieved
+		 * successfully, the first argument passed will be an instance of Theme_Update. Otherwise,
+		 * it will be NULL. The second argument will be the corresponding return value of
+		 * wp_remote_get (see WP docs for details).
+		 *
+		 * The callback function should return a new or modified instance of Theme_Update or NULL.
+		 *
+		 * @uses add_filter() This method is a convenience wrapper for add_filter().
+		 *
+		 * @param callable $callback
+		 * @return void
+		 */
+		public function addResultFilter($callback) {
+			$this->addFilter('request_update_result', $callback, 10, 2);
+		}
+
+		/**
+		 * Create a package instance that represents this plugin or theme.
+		 *
+		 * @return InstalledPackage
+		 */
+		protected function createInstalledPackage() {
+			return new Package($this->stylesheet, $this);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Update.php

@@ -0,0 +1,38 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+use stdClass;
+
+if ( !class_exists(Update::class, false) ):
+
+	/**
+	 * A simple container class for holding information about an available update.
+	 *
+	 * @author Janis Elsts
+	 * @access public
+	 */
+	abstract class Update extends Metadata {
+		public $slug;
+		public $version;
+		public $download_url;
+		public $translations = array();
+
+		/**
+		 * @return string[]
+		 */
+		protected function getFieldNames() {
+			return array('slug', 'version', 'download_url', 'translations');
+		}
+
+		public function toWpFormat() {
+			$update = new stdClass();
+
+			$update->slug = $this->slug;
+			$update->new_version = $this->version;
+			$update->package = $this->download_url;
+
+			return $update;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/UpgraderStatus.php

@@ -0,0 +1,200 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(UpgraderStatus::class, false) ):
+
+	/**
+	 * A utility class that helps figure out which plugin or theme WordPress is upgrading.
+	 *
+	 * It may seem strange to have a separate class just for that, but the task is surprisingly complicated.
+	 * Core classes like Plugin_Upgrader don't expose the plugin file name during an in-progress update (AFAICT).
+	 * This class uses a few workarounds and heuristics to get the file name.
+	 */
+	class UpgraderStatus {
+		private $currentType = null; //This must be either "plugin" or "theme".
+		private $currentId = null;   //Plugin basename or theme directory name.
+
+		public function __construct() {
+			//Keep track of which plugin/theme WordPress is currently upgrading.
+			add_filter('upgrader_pre_install', array($this, 'setUpgradedThing'), 10, 2);
+			add_filter('upgrader_package_options', array($this, 'setUpgradedPluginFromOptions'), 10, 1);
+			add_filter('upgrader_post_install', array($this, 'clearUpgradedThing'), 10, 1);
+			add_action('upgrader_process_complete', array($this, 'clearUpgradedThing'), 10, 1);
+		}
+
+		/**
+		 * Is there and update being installed RIGHT NOW, for a specific plugin?
+		 *
+		 * Caution: This method is unreliable. WordPress doesn't make it easy to figure out what it is upgrading,
+		 * and upgrader implementations are liable to change without notice.
+		 *
+		 * @param string $pluginFile The plugin to check.
+		 * @param \WP_Upgrader|null $upgrader The upgrader that's performing the current update.
+		 * @return bool True if the plugin identified by $pluginFile is being upgraded.
+		 */
+		public function isPluginBeingUpgraded($pluginFile, $upgrader = null) {
+			return $this->isBeingUpgraded('plugin', $pluginFile, $upgrader);
+		}
+
+		/**
+		 * Is there an update being installed for a specific theme?
+		 *
+		 * @param string $stylesheet Theme directory name.
+		 * @param \WP_Upgrader|null $upgrader The upgrader that's performing the current update.
+		 * @return bool
+		 */
+		public function isThemeBeingUpgraded($stylesheet, $upgrader = null) {
+			return $this->isBeingUpgraded('theme', $stylesheet, $upgrader);
+		}
+
+		/**
+		 * Check if a specific theme or plugin is being upgraded.
+		 *
+		 * @param string $type
+		 * @param string $id
+		 * @param \Plugin_Upgrader|\WP_Upgrader|null $upgrader
+		 * @return bool
+		 */
+		protected function isBeingUpgraded($type, $id, $upgrader = null) {
+			if ( isset($upgrader) ) {
+				list($currentType, $currentId) = $this->getThingBeingUpgradedBy($upgrader);
+				if ( $currentType !== null ) {
+					$this->currentType = $currentType;
+					$this->currentId = $currentId;
+				}
+			}
+			return ($this->currentType === $type) && ($this->currentId === $id);
+		}
+
+		/**
+		 * Figure out which theme or plugin is being upgraded by a WP_Upgrader instance.
+		 *
+		 * Returns an array with two items. The first item is the type of the thing that's being
+		 * upgraded: "plugin" or "theme". The second item is either the plugin basename or
+		 * the theme directory name. If we can't determine what the upgrader is doing, both items
+		 * will be NULL.
+		 *
+		 * Examples:
+		 *      ['plugin', 'plugin-dir-name/plugin.php']
+		 *      ['theme', 'theme-dir-name']
+		 *
+		 * @param \Plugin_Upgrader|\WP_Upgrader $upgrader
+		 * @return array
+		 */
+		private function getThingBeingUpgradedBy($upgrader) {
+			if ( !isset($upgrader, $upgrader->skin) ) {
+				return array(null, null);
+			}
+
+			//Figure out which plugin or theme is being upgraded.
+			$pluginFile = null;
+			$themeDirectoryName = null;
+
+			$skin = $upgrader->skin;
+			if ( isset($skin->theme_info) && ($skin->theme_info instanceof \WP_Theme) ) {
+				$themeDirectoryName = $skin->theme_info->get_stylesheet();
+			} elseif ( $skin instanceof \Plugin_Upgrader_Skin ) {
+				if ( isset($skin->plugin) && is_string($skin->plugin) && ($skin->plugin !== '') ) {
+					$pluginFile = $skin->plugin;
+				}
+			} elseif ( $skin instanceof \Theme_Upgrader_Skin ) {
+				if ( isset($skin->theme) && is_string($skin->theme) && ($skin->theme !== '') ) {
+					$themeDirectoryName = $skin->theme;
+				}
+			} elseif ( isset($skin->plugin_info) && is_array($skin->plugin_info) ) {
+				//This case is tricky because Bulk_Plugin_Upgrader_Skin (etc) doesn't actually store the plugin
+				//filename anywhere. Instead, it has the plugin headers in $plugin_info. So the best we can
+				//do is compare those headers to the headers of installed plugins.
+				$pluginFile = $this->identifyPluginByHeaders($skin->plugin_info);
+			}
+
+			if ( $pluginFile !== null ) {
+				return array('plugin', $pluginFile);
+			} elseif ( $themeDirectoryName !== null ) {
+				return array('theme', $themeDirectoryName);
+			}
+			return array(null, null);
+		}
+
+		/**
+		 * Identify an installed plugin based on its headers.
+		 *
+		 * @param array $searchHeaders The plugin file header to look for.
+		 * @return string|null Plugin basename ("foo/bar.php"), or NULL if we can't identify the plugin.
+		 */
+		private function identifyPluginByHeaders($searchHeaders) {
+			if ( !function_exists('get_plugins') ){
+				require_once( ABSPATH . '/wp-admin/includes/plugin.php' );
+			}
+
+			$installedPlugins = get_plugins();
+			$matches = array();
+			foreach($installedPlugins as $pluginBasename => $headers) {
+				$diff1 = array_diff_assoc($headers, $searchHeaders);
+				$diff2 = array_diff_assoc($searchHeaders, $headers);
+				if ( empty($diff1) && empty($diff2) ) {
+					$matches[] = $pluginBasename;
+				}
+			}
+
+			//It's possible (though very unlikely) that there could be two plugins with identical
+			//headers. In that case, we can't unambiguously identify the plugin that's being upgraded.
+			if ( count($matches) !== 1 ) {
+				return null;
+			}
+
+			return reset($matches);
+		}
+
+		/**
+		 * @access private
+		 *
+		 * @param mixed $input
+		 * @param array $hookExtra
+		 * @return mixed Returns $input unaltered.
+		 */
+		public function setUpgradedThing($input, $hookExtra) {
+			if ( !empty($hookExtra['plugin']) && is_string($hookExtra['plugin']) ) {
+				$this->currentId = $hookExtra['plugin'];
+				$this->currentType = 'plugin';
+			} elseif ( !empty($hookExtra['theme']) && is_string($hookExtra['theme']) ) {
+				$this->currentId = $hookExtra['theme'];
+				$this->currentType = 'theme';
+			} else {
+				$this->currentType = null;
+				$this->currentId = null;
+			}
+			return $input;
+		}
+
+		/**
+		 * @access private
+		 *
+		 * @param array $options
+		 * @return array
+		 */
+		public function setUpgradedPluginFromOptions($options) {
+			if ( isset($options['hook_extra']['plugin']) && is_string($options['hook_extra']['plugin']) ) {
+				$this->currentType = 'plugin';
+				$this->currentId = $options['hook_extra']['plugin'];
+			} else {
+				$this->currentType = null;
+				$this->currentId = null;
+			}
+			return $options;
+		}
+
+		/**
+		 * @access private
+		 *
+		 * @param mixed $input
+		 * @return mixed Returns $input unaltered.
+		 */
+		public function clearUpgradedThing($input = null) {
+			$this->currentId = null;
+			$this->currentType = null;
+			return $input;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Utils.php

@@ -0,0 +1,70 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3;
+
+if ( !class_exists(Utils::class, false) ):
+
+	class Utils {
+		/**
+		 * Get a value from a nested array or object based on a path.
+		 *
+		 * @param array|object|null $collection Get an entry from this array.
+		 * @param array|string $path A list of array keys in hierarchy order, or a string path like "foo.bar.baz".
+		 * @param mixed $default The value to return if the specified path is not found.
+		 * @param string $separator Path element separator. Only applies to string paths.
+		 * @return mixed
+		 */
+		public static function get($collection, $path, $default = null, $separator = '.') {
+			if ( is_string($path) ) {
+				$path = explode($separator, $path);
+			}
+
+			//Follow the $path into $input as far as possible.
+			$currentValue = $collection;
+			foreach ($path as $node) {
+				if ( is_array($currentValue) && isset($currentValue[$node]) ) {
+					$currentValue = $currentValue[$node];
+				} else if ( is_object($currentValue) && isset($currentValue->$node) ) {
+					$currentValue = $currentValue->$node;
+				} else {
+					return $default;
+				}
+			}
+
+			return $currentValue;
+		}
+
+		/**
+		 * Get the first array element that is not empty.
+		 *
+		 * @param array $values
+		 * @param mixed|null $default Returns this value if there are no non-empty elements.
+		 * @return mixed|null
+		 */
+		public static function findNotEmpty($values, $default = null) {
+			if ( empty($values) ) {
+				return $default;
+			}
+
+			foreach ($values as $value) {
+				if ( !empty($value) ) {
+					return $value;
+				}
+			}
+
+			return $default;
+		}
+
+		/**
+		 * Check if the input string starts with the specified prefix.
+		 *
+		 * @param string $input
+		 * @param string $prefix
+		 * @return bool
+		 */
+		public static function startsWith($input, $prefix) {
+			$length = strlen($prefix);
+			return (substr($input, 0, $length) === $prefix);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/Api.php

@@ -0,0 +1,379 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+use Parsedown;
+use PucReadmeParser;
+
+if ( !class_exists(Api::class, false) ):
+
+	abstract class Api {
+		const STRATEGY_LATEST_RELEASE = 'latest_release';
+		const STRATEGY_LATEST_TAG = 'latest_tag';
+		const STRATEGY_STABLE_TAG = 'stable_tag';
+		const STRATEGY_BRANCH = 'branch';
+
+		/**
+		 * Consider all releases regardless of their version number or prerelease/upcoming
+		 * release status.
+		 */
+		const RELEASE_FILTER_ALL = 3;
+
+		/**
+		 * Exclude releases that have the "prerelease" or "upcoming release" flag.
+		 *
+		 * This does *not* look for prerelease keywords like "beta" in the version number.
+		 * It only uses the data provided by the API. For example, on GitHub, you can
+		 * manually mark a release as a prerelease.
+		 */
+		const RELEASE_FILTER_SKIP_PRERELEASE = 1;
+
+		/**
+		 * If there are no release assets or none of them match the configured filter,
+		 * fall back to the automatically generated source code archive.
+		 */
+		const PREFER_RELEASE_ASSETS = 1;
+		/**
+		 * Skip releases that don't have any matching release assets.
+		 */
+		const REQUIRE_RELEASE_ASSETS = 2;
+
+		protected $tagNameProperty = 'name';
+		protected $slug = '';
+
+		/**
+		 * @var string
+		 */
+		protected $repositoryUrl = '';
+
+		/**
+		 * @var mixed Authentication details for private repositories. Format depends on service.
+		 */
+		protected $credentials = null;
+
+		/**
+		 * @var string The filter tag that's used to filter options passed to wp_remote_get.
+		 * For example, "puc_request_info_options-slug" or "puc_request_update_options_theme-slug".
+		 */
+		protected $httpFilterName = '';
+
+		/**
+		 * @var string The filter applied to the list of update detection strategies that
+		 * are used to find the latest version.
+		 */
+		protected $strategyFilterName = '';
+
+		/**
+		 * @var string|null
+		 */
+		protected $localDirectory = null;
+
+		/**
+		 * Api constructor.
+		 *
+		 * @param string $repositoryUrl
+		 * @param array|string|null $credentials
+		 */
+		public function __construct($repositoryUrl, $credentials = null) {
+			$this->repositoryUrl = $repositoryUrl;
+			$this->setAuthentication($credentials);
+		}
+
+		/**
+		 * @return string
+		 */
+		public function getRepositoryUrl() {
+			return $this->repositoryUrl;
+		}
+
+		/**
+		 * Figure out which reference (i.e. tag or branch) contains the latest version.
+		 *
+		 * @param string $configBranch Start looking in this branch.
+		 * @return null|Reference
+		 */
+		public function chooseReference($configBranch) {
+			$strategies = $this->getUpdateDetectionStrategies($configBranch);
+
+			if ( !empty($this->strategyFilterName) ) {
+				$strategies = apply_filters(
+					$this->strategyFilterName,
+					$strategies,
+					$this->slug
+				);
+			}
+
+			foreach ($strategies as $strategy) {
+				$reference = call_user_func($strategy);
+				if ( !empty($reference) ) {
+					return $reference;
+				}
+			}
+			return null;
+		}
+
+		/**
+		 * Get an ordered list of strategies that can be used to find the latest version.
+		 *
+		 * The update checker will try each strategy in order until one of them
+		 * returns a valid reference.
+		 *
+		 * @param string $configBranch
+		 * @return array<callable> Array of callables that return Vcs_Reference objects.
+		 */
+		abstract protected function getUpdateDetectionStrategies($configBranch);
+
+		/**
+		 * Get the readme.txt file from the remote repository and parse it
+		 * according to the plugin readme standard.
+		 *
+		 * @param string $ref Tag or branch name.
+		 * @return array Parsed readme.
+		 */
+		public function getRemoteReadme($ref = 'master') {
+			$fileContents = $this->getRemoteFile($this->getLocalReadmeName(), $ref);
+			if ( empty($fileContents) ) {
+				return array();
+			}
+
+			$parser = new PucReadmeParser();
+			return $parser->parse_readme_contents($fileContents);
+		}
+
+		/**
+		 * Get the case-sensitive name of the local readme.txt file.
+		 *
+		 * In most cases it should just be called "readme.txt", but some plugins call it "README.txt",
+		 * "README.TXT", or even "Readme.txt". Most VCS are case-sensitive so we need to know the correct
+		 * capitalization.
+		 *
+		 * Defaults to "readme.txt" (all lowercase).
+		 *
+		 * @return string
+		 */
+		public function getLocalReadmeName() {
+			static $fileName = null;
+			if ( $fileName !== null ) {
+				return $fileName;
+			}
+
+			$fileName = 'readme.txt';
+			if ( isset($this->localDirectory) ) {
+				$files = scandir($this->localDirectory);
+				if ( !empty($files) ) {
+					foreach ($files as $possibleFileName) {
+						if ( strcasecmp($possibleFileName, 'readme.txt') === 0 ) {
+							$fileName = $possibleFileName;
+							break;
+						}
+					}
+				}
+			}
+			return $fileName;
+		}
+
+		/**
+		 * Get a branch.
+		 *
+		 * @param string $branchName
+		 * @return Reference|null
+		 */
+		abstract public function getBranch($branchName);
+
+		/**
+		 * Get a specific tag.
+		 *
+		 * @param string $tagName
+		 * @return Reference|null
+		 */
+		abstract public function getTag($tagName);
+
+		/**
+		 * Get the tag that looks like the highest version number.
+		 * (Implementations should skip pre-release versions if possible.)
+		 *
+		 * @return Reference|null
+		 */
+		abstract public function getLatestTag();
+
+		/**
+		 * Check if a tag name string looks like a version number.
+		 *
+		 * @param string $name
+		 * @return bool
+		 */
+		protected function looksLikeVersion($name) {
+			//Tag names may be prefixed with "v", e.g. "v1.2.3".
+			$name = ltrim($name, 'v');
+
+			//The version string must start with a number.
+			if ( !is_numeric(substr($name, 0, 1)) ) {
+				return false;
+			}
+
+			//The goal is to accept any SemVer-compatible or "PHP-standardized" version number.
+			return (preg_match('@^(\d{1,5}?)(\.\d{1,10}?){0,4}?($|[abrdp+_\-]|\s)@i', $name) === 1);
+		}
+
+		/**
+		 * Check if a tag appears to be named like a version number.
+		 *
+		 * @param \stdClass $tag
+		 * @return bool
+		 */
+		protected function isVersionTag($tag) {
+			$property = $this->tagNameProperty;
+			return isset($tag->$property) && $this->looksLikeVersion($tag->$property);
+		}
+
+		/**
+		 * Sort a list of tags as if they were version numbers.
+		 * Tags that don't look like version number will be removed.
+		 *
+		 * @param \stdClass[] $tags Array of tag objects.
+		 * @return \stdClass[] Filtered array of tags sorted in descending order.
+		 */
+		protected function sortTagsByVersion($tags) {
+			//Keep only those tags that look like version numbers.
+			$versionTags = array_filter($tags, array($this, 'isVersionTag'));
+			//Sort them in descending order.
+			usort($versionTags, array($this, 'compareTagNames'));
+
+			return $versionTags;
+		}
+
+		/**
+		 * Compare two tags as if they were version number.
+		 *
+		 * @param \stdClass $tag1 Tag object.
+		 * @param \stdClass $tag2 Another tag object.
+		 * @return int
+		 */
+		protected function compareTagNames($tag1, $tag2) {
+			$property = $this->tagNameProperty;
+			if ( !isset($tag1->$property) ) {
+				return 1;
+			}
+			if ( !isset($tag2->$property) ) {
+				return -1;
+			}
+			return -version_compare(ltrim($tag1->$property, 'v'), ltrim($tag2->$property, 'v'));
+		}
+
+		/**
+		 * Get the contents of a file from a specific branch or tag.
+		 *
+		 * @param string $path File name.
+		 * @param string $ref
+		 * @return null|string Either the contents of the file, or null if the file doesn't exist or there's an error.
+		 */
+		abstract public function getRemoteFile($path, $ref = 'master');
+
+		/**
+		 * Get the timestamp of the latest commit that changed the specified branch or tag.
+		 *
+		 * @param string $ref Reference name (e.g. branch or tag).
+		 * @return string|null
+		 */
+		abstract public function getLatestCommitTime($ref);
+
+		/**
+		 * Get the contents of the changelog file from the repository.
+		 *
+		 * @param string $ref
+		 * @param string $localDirectory Full path to the local plugin or theme directory.
+		 * @return null|string The HTML contents of the changelog.
+		 */
+		public function getRemoteChangelog($ref, $localDirectory) {
+			$filename = $this->findChangelogName($localDirectory);
+			if ( empty($filename) ) {
+				return null;
+			}
+
+			$changelog = $this->getRemoteFile($filename, $ref);
+			if ( $changelog === null ) {
+				return null;
+			}
+
+			return Parsedown::instance()->text($changelog);
+		}
+
+		/**
+		 * Guess the name of the changelog file.
+		 *
+		 * @param string $directory
+		 * @return string|null
+		 */
+		protected function findChangelogName($directory = null) {
+			if ( !isset($directory) ) {
+				$directory = $this->localDirectory;
+			}
+			if ( empty($directory) || !is_dir($directory) || ($directory === '.') ) {
+				return null;
+			}
+
+			$possibleNames = array('CHANGES.md', 'CHANGELOG.md', 'changes.md', 'changelog.md');
+			$files = scandir($directory);
+			$foundNames = array_intersect($possibleNames, $files);
+
+			if ( !empty($foundNames) ) {
+				return reset($foundNames);
+			}
+			return null;
+		}
+
+		/**
+		 * Set authentication credentials.
+		 *
+		 * @param $credentials
+		 */
+		public function setAuthentication($credentials) {
+			$this->credentials = $credentials;
+		}
+
+		public function isAuthenticationEnabled() {
+			return !empty($this->credentials);
+		}
+
+		/**
+		 * @param string $url
+		 * @return string
+		 */
+		public function signDownloadUrl($url) {
+			return $url;
+		}
+
+		/**
+		 * @param string $filterName
+		 */
+		public function setHttpFilterName($filterName) {
+			$this->httpFilterName = $filterName;
+		}
+
+		/**
+		 * @param string $filterName
+		 */
+		public function setStrategyFilterName($filterName) {
+			$this->strategyFilterName = $filterName;
+		}
+
+		/**
+		 * @param string $directory
+		 */
+		public function setLocalDirectory($directory) {
+			if ( empty($directory) || !is_dir($directory) || ($directory === '.') ) {
+				$this->localDirectory = null;
+			} else {
+				$this->localDirectory = $directory;
+			}
+		}
+
+		/**
+		 * @param string $slug
+		 */
+		public function setSlug($slug) {
+			$this->slug = $slug;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/BaseChecker.php

@@ -0,0 +1,29 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !interface_exists(BaseChecker::class, false) ):
+
+	interface BaseChecker {
+		/**
+		 * Set the repository branch to use for updates. Defaults to 'master'.
+		 *
+		 * @param string $branch
+		 * @return $this
+		 */
+		public function setBranch($branch);
+
+		/**
+		 * Set authentication credentials.
+		 *
+		 * @param array|string $credentials
+		 * @return $this
+		 */
+		public function setAuthentication($credentials);
+
+		/**
+		 * @return Api
+		 */
+		public function getVcsApi();
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/BitBucketApi.php

@@ -0,0 +1,272 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\OAuthSignature;
+use YahnisElsts\PluginUpdateChecker\v5p3\Utils;
+
+if ( !class_exists(BitBucketApi::class, false) ):
+
+	class BitBucketApi extends Api {
+		/**
+		 * @var OAuthSignature
+		 */
+		private $oauth = null;
+
+		/**
+		 * @var string
+		 */
+		private $username;
+
+		/**
+		 * @var string
+		 */
+		private $repository;
+
+		public function __construct($repositoryUrl, $credentials = array()) {
+			$path = wp_parse_url($repositoryUrl, PHP_URL_PATH);
+			if ( preg_match('@^/?(?P<username>[^/]+?)/(?P<repository>[^/#?&]+?)/?$@', $path, $matches) ) {
+				$this->username = $matches['username'];
+				$this->repository = $matches['repository'];
+			} else {
+				throw new \InvalidArgumentException('Invalid BitBucket repository URL: "' . $repositoryUrl . '"');
+			}
+
+			parent::__construct($repositoryUrl, $credentials);
+		}
+
+		protected function getUpdateDetectionStrategies($configBranch) {
+			$strategies = array(
+				self::STRATEGY_STABLE_TAG => function () use ($configBranch) {
+					return $this->getStableTag($configBranch);
+				},
+			);
+
+			if ( ($configBranch === 'master' || $configBranch === 'main') ) {
+				$strategies[self::STRATEGY_LATEST_TAG] = array($this, 'getLatestTag');
+			}
+
+			$strategies[self::STRATEGY_BRANCH] = function () use ($configBranch) {
+				return $this->getBranch($configBranch);
+			};
+			return $strategies;
+		}
+
+		public function getBranch($branchName) {
+			$branch = $this->api('/refs/branches/' . $branchName);
+			if ( is_wp_error($branch) || empty($branch) ) {
+				return null;
+			}
+
+			//The "/src/{stuff}/{path}" endpoint doesn't seem to handle branch names that contain slashes.
+			//If we don't encode the slash, we get a 404. If we encode it as "%2F", we get a 401.
+			//To avoid issues, if the branch name is not URL-safe, let's use the commit hash instead.
+			$ref = $branch->name;
+			if ((urlencode($ref) !== $ref) && isset($branch->target->hash)) {
+				$ref = $branch->target->hash;
+			}
+
+			return new Reference(array(
+				'name' => $ref,
+				'updated' => $branch->target->date,
+				'downloadUrl' => $this->getDownloadUrl($branch->name),
+			));
+		}
+
+		/**
+		 * Get a specific tag.
+		 *
+		 * @param string $tagName
+		 * @return Reference|null
+		 */
+		public function getTag($tagName) {
+			$tag = $this->api('/refs/tags/' . $tagName);
+			if ( is_wp_error($tag) || empty($tag) ) {
+				return null;
+			}
+
+			return new Reference(array(
+				'name' => $tag->name,
+				'version' => ltrim($tag->name, 'v'),
+				'updated' => $tag->target->date,
+				'downloadUrl' => $this->getDownloadUrl($tag->name),
+			));
+		}
+
+		/**
+		 * Get the tag that looks like the highest version number.
+		 *
+		 * @return Reference|null
+		 */
+		public function getLatestTag() {
+			$tags = $this->api('/refs/tags?sort=-target.date');
+			if ( !isset($tags, $tags->values) || !is_array($tags->values) ) {
+				return null;
+			}
+
+			//Filter and sort the list of tags.
+			$versionTags = $this->sortTagsByVersion($tags->values);
+
+			//Return the first result.
+			if ( !empty($versionTags) ) {
+				$tag = $versionTags[0];
+				return new Reference(array(
+					'name' => $tag->name,
+					'version' => ltrim($tag->name, 'v'),
+					'updated' => $tag->target->date,
+					'downloadUrl' => $this->getDownloadUrl($tag->name),
+				));
+			}
+			return null;
+		}
+
+		/**
+		 * Get the tag/ref specified by the "Stable tag" header in the readme.txt of a given branch.
+		 *
+		 * @param string $branch
+		 * @return null|Reference
+		 */
+		protected function getStableTag($branch) {
+			$remoteReadme = $this->getRemoteReadme($branch);
+			if ( !empty($remoteReadme['stable_tag']) ) {
+				$tag = $remoteReadme['stable_tag'];
+
+				//You can explicitly opt out of using tags by setting "Stable tag" to
+				//"trunk" or the name of the current branch.
+				if ( ($tag === $branch) || ($tag === 'trunk') ) {
+					return $this->getBranch($branch);
+				}
+
+				return $this->getTag($tag);
+			}
+
+			return null;
+		}
+
+		/**
+		 * @param string $ref
+		 * @return string
+		 */
+		protected function getDownloadUrl($ref) {
+			return sprintf(
+				'https://bitbucket.org/%s/%s/get/%s.zip',
+				$this->username,
+				$this->repository,
+				$ref
+			);
+		}
+
+		/**
+		 * Get the contents of a file from a specific branch or tag.
+		 *
+		 * @param string $path File name.
+		 * @param string $ref
+		 * @return null|string Either the contents of the file, or null if the file doesn't exist or there's an error.
+		 */
+		public function getRemoteFile($path, $ref = 'master') {
+			$response = $this->api('src/' . $ref . '/' . ltrim($path));
+			if ( is_wp_error($response) || !is_string($response) ) {
+				return null;
+			}
+			return $response;
+		}
+
+		/**
+		 * Get the timestamp of the latest commit that changed the specified branch or tag.
+		 *
+		 * @param string $ref Reference name (e.g. branch or tag).
+		 * @return string|null
+		 */
+		public function getLatestCommitTime($ref) {
+			$response = $this->api('commits/' . $ref);
+			if ( isset($response->values, $response->values[0], $response->values[0]->date) ) {
+				return $response->values[0]->date;
+			}
+			return null;
+		}
+
+		/**
+		 * Perform a BitBucket API 2.0 request.
+		 *
+		 * @param string $url
+		 * @param string $version
+		 * @return mixed|\WP_Error
+		 */
+		public function api($url, $version = '2.0') {
+			$url = ltrim($url, '/');
+			$isSrcResource = Utils::startsWith($url, 'src/');
+
+			$url = implode('/', array(
+				'https://api.bitbucket.org',
+				$version,
+				'repositories',
+				$this->username,
+				$this->repository,
+				$url
+			));
+			$baseUrl = $url;
+
+			if ( $this->oauth ) {
+				$url = $this->oauth->sign($url,'GET');
+			}
+
+			$options = array('timeout' => wp_doing_cron() ? 10 : 3);
+			if ( !empty($this->httpFilterName) ) {
+				$options = apply_filters($this->httpFilterName, $options);
+			}
+			$response = wp_remote_get($url, $options);
+			if ( is_wp_error($response) ) {
+				do_action('puc_api_error', $response, null, $url, $this->slug);
+				return $response;
+			}
+
+			$code = wp_remote_retrieve_response_code($response);
+			$body = wp_remote_retrieve_body($response);
+			if ( $code === 200 ) {
+				if ( $isSrcResource ) {
+					//Most responses are JSON-encoded, but src resources just
+					//return raw file contents.
+					$document = $body;
+				} else {
+					$document = json_decode($body);
+				}
+				return $document;
+			}
+
+			$error = new \WP_Error(
+				'puc-bitbucket-http-error',
+				sprintf('BitBucket API error. Base URL: "%s",  HTTP status code: %d.', $baseUrl, $code)
+			);
+			do_action('puc_api_error', $error, $response, $url, $this->slug);
+
+			return $error;
+		}
+
+		/**
+		 * @param array $credentials
+		 */
+		public function setAuthentication($credentials) {
+			parent::setAuthentication($credentials);
+
+			if ( !empty($credentials) && !empty($credentials['consumer_key']) ) {
+				$this->oauth = new OAuthSignature(
+					$credentials['consumer_key'],
+					$credentials['consumer_secret']
+				);
+			} else {
+				$this->oauth = null;
+			}
+		}
+
+		public function signDownloadUrl($url) {
+			//Add authentication data to download URLs. Since OAuth signatures incorporate
+			//timestamps, we have to do this immediately before inserting the update. Otherwise,
+			//authentication could fail due to a stale timestamp.
+			if ( $this->oauth ) {
+				$url = $this->oauth->sign($url);
+			}
+			return $url;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/GitHubApi.php

@@ -0,0 +1,467 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+use Parsedown;
+
+if ( !class_exists(GitHubApi::class, false) ):
+
+	class GitHubApi extends Api {
+		use ReleaseAssetSupport;
+		use ReleaseFilteringFeature;
+
+		/**
+		 * @var string GitHub username.
+		 */
+		protected $userName;
+		/**
+		 * @var string GitHub repository name.
+		 */
+		protected $repositoryName;
+
+		/**
+		 * @var string Either a fully qualified repository URL, or just "user/repo-name".
+		 */
+		protected $repositoryUrl;
+
+		/**
+		 * @var string GitHub authentication token. Optional.
+		 */
+		protected $accessToken;
+
+		/**
+		 * @var bool
+		 */
+		private $downloadFilterAdded = false;
+
+		public function __construct($repositoryUrl, $accessToken = null) {
+			$path = wp_parse_url($repositoryUrl, PHP_URL_PATH);
+			if ( preg_match('@^/?(?P<username>[^/]+?)/(?P<repository>[^/#?&]+?)/?$@', $path, $matches) ) {
+				$this->userName = $matches['username'];
+				$this->repositoryName = $matches['repository'];
+			} else {
+				throw new \InvalidArgumentException('Invalid GitHub repository URL: "' . $repositoryUrl . '"');
+			}
+
+			parent::__construct($repositoryUrl, $accessToken);
+		}
+
+		/**
+		 * Get the latest release from GitHub.
+		 *
+		 * @return Reference|null
+		 */
+		public function getLatestRelease() {
+			//The "latest release" endpoint returns one release and always skips pre-releases,
+			//so we can only use it if that's compatible with the current filter settings.
+			if (
+				$this->shouldSkipPreReleases()
+				&& (
+					($this->releaseFilterMaxReleases === 1) || !$this->hasCustomReleaseFilter()
+				)
+			) {
+				//Just get the latest release.
+				$release = $this->api('/repos/:user/:repo/releases/latest');
+				if ( is_wp_error($release) || !is_object($release) || !isset($release->tag_name) ) {
+					return null;
+				}
+				$foundReleases = array($release);
+			} else {
+				//Get a list of the most recent releases.
+				$foundReleases = $this->api(
+					'/repos/:user/:repo/releases',
+					array('per_page' => $this->releaseFilterMaxReleases)
+				);
+				if ( is_wp_error($foundReleases) || !is_array($foundReleases) ) {
+					return null;
+				}
+			}
+
+			foreach ($foundReleases as $release) {
+				//Always skip drafts.
+				if ( isset($release->draft) && !empty($release->draft) ) {
+					continue;
+				}
+
+				//Skip pre-releases unless specifically included.
+				if (
+					$this->shouldSkipPreReleases()
+					&& isset($release->prerelease)
+					&& !empty($release->prerelease)
+				) {
+					continue;
+				}
+
+				$versionNumber = ltrim($release->tag_name, 'v'); //Remove the "v" prefix from "v1.2.3".
+
+				//Custom release filtering.
+				if ( !$this->matchesCustomReleaseFilter($versionNumber, $release) ) {
+					continue;
+				}
+
+				$reference = new Reference(array(
+					'name'        => $release->tag_name,
+					'version'     => $versionNumber,
+					'downloadUrl' => $release->zipball_url,
+					'updated'     => $release->created_at,
+					'apiResponse' => $release,
+				));
+
+				if ( isset($release->assets[0]) ) {
+					$reference->downloadCount = $release->assets[0]->download_count;
+				}
+
+				if ( $this->releaseAssetsEnabled ) {
+					//Use the first release asset that matches the specified regular expression.
+					if ( isset($release->assets, $release->assets[0]) ) {
+						$matchingAssets = array_values(array_filter($release->assets, array($this, 'matchesAssetFilter')));
+					} else {
+						$matchingAssets = array();
+					}
+
+					if ( !empty($matchingAssets) ) {
+						if ( $this->isAuthenticationEnabled() ) {
+							/**
+							 * Keep in mind that we'll need to add an "Accept" header to download this asset.
+							 *
+							 * @see setUpdateDownloadHeaders()
+							 */
+							$reference->downloadUrl = $matchingAssets[0]->url;
+						} else {
+							//It seems that browser_download_url only works for public repositories.
+							//Using an access_token doesn't help. Maybe OAuth would work?
+							$reference->downloadUrl = $matchingAssets[0]->browser_download_url;
+						}
+
+						$reference->downloadCount = $matchingAssets[0]->download_count;
+					} else if ( $this->releaseAssetPreference === Api::REQUIRE_RELEASE_ASSETS ) {
+						//None of the assets match the filter, and we're not allowed
+						//to fall back to the auto-generated source ZIP.
+						return null;
+					}
+				}
+
+				if ( !empty($release->body) ) {
+					$reference->changelog = Parsedown::instance()->text($release->body);
+				}
+
+				return $reference;
+			}
+
+			return null;
+		}
+
+		/**
+		 * Get the tag that looks like the highest version number.
+		 *
+		 * @return Reference|null
+		 */
+		public function getLatestTag() {
+			$tags = $this->api('/repos/:user/:repo/tags');
+
+			if ( is_wp_error($tags) || !is_array($tags) ) {
+				return null;
+			}
+
+			$versionTags = $this->sortTagsByVersion($tags);
+			if ( empty($versionTags) ) {
+				return null;
+			}
+
+			$tag = $versionTags[0];
+			return new Reference(array(
+				'name'        => $tag->name,
+				'version'     => ltrim($tag->name, 'v'),
+				'downloadUrl' => $tag->zipball_url,
+				'apiResponse' => $tag,
+			));
+		}
+
+		/**
+		 * Get a branch by name.
+		 *
+		 * @param string $branchName
+		 * @return null|Reference
+		 */
+		public function getBranch($branchName) {
+			$branch = $this->api('/repos/:user/:repo/branches/' . $branchName);
+			if ( is_wp_error($branch) || empty($branch) ) {
+				return null;
+			}
+
+			$reference = new Reference(array(
+				'name'        => $branch->name,
+				'downloadUrl' => $this->buildArchiveDownloadUrl($branch->name),
+				'apiResponse' => $branch,
+			));
+
+			if ( isset($branch->commit, $branch->commit->commit, $branch->commit->commit->author->date) ) {
+				$reference->updated = $branch->commit->commit->author->date;
+			}
+
+			return $reference;
+		}
+
+		/**
+		 * Get the latest commit that changed the specified file.
+		 *
+		 * @param string $filename
+		 * @param string $ref Reference name (e.g. branch or tag).
+		 * @return \StdClass|null
+		 */
+		public function getLatestCommit($filename, $ref = 'master') {
+			$commits = $this->api(
+				'/repos/:user/:repo/commits',
+				array(
+					'path' => $filename,
+					'sha'  => $ref,
+				)
+			);
+			if ( !is_wp_error($commits) && isset($commits[0]) ) {
+				return $commits[0];
+			}
+			return null;
+		}
+
+		/**
+		 * Get the timestamp of the latest commit that changed the specified branch or tag.
+		 *
+		 * @param string $ref Reference name (e.g. branch or tag).
+		 * @return string|null
+		 */
+		public function getLatestCommitTime($ref) {
+			$commits = $this->api('/repos/:user/:repo/commits', array('sha' => $ref));
+			if ( !is_wp_error($commits) && isset($commits[0]) ) {
+				return $commits[0]->commit->author->date;
+			}
+			return null;
+		}
+
+		/**
+		 * Perform a GitHub API request.
+		 *
+		 * @param string $url
+		 * @param array $queryParams
+		 * @return mixed|\WP_Error
+		 */
+		protected function api($url, $queryParams = array()) {
+			$baseUrl = $url;
+			$url = $this->buildApiUrl($url, $queryParams);
+
+			$options = array('timeout' => wp_doing_cron() ? 10 : 3);
+			if ( $this->isAuthenticationEnabled() ) {
+				$options['headers'] = array('Authorization' => $this->getAuthorizationHeader());
+			}
+
+			if ( !empty($this->httpFilterName) ) {
+				$options = apply_filters($this->httpFilterName, $options);
+			}
+			$response = wp_remote_get($url, $options);
+			if ( is_wp_error($response) ) {
+				do_action('puc_api_error', $response, null, $url, $this->slug);
+				return $response;
+			}
+
+			$code = wp_remote_retrieve_response_code($response);
+			$body = wp_remote_retrieve_body($response);
+			if ( $code === 200 ) {
+				$document = json_decode($body);
+				return $document;
+			}
+
+			$error = new \WP_Error(
+				'puc-github-http-error',
+				sprintf('GitHub API error. Base URL: "%s",  HTTP status code: %d.', $baseUrl, $code)
+			);
+			do_action('puc_api_error', $error, $response, $url, $this->slug);
+
+			return $error;
+		}
+
+		/**
+		 * Build a fully qualified URL for an API request.
+		 *
+		 * @param string $url
+		 * @param array $queryParams
+		 * @return string
+		 */
+		protected function buildApiUrl($url, $queryParams) {
+			$variables = array(
+				'user' => $this->userName,
+				'repo' => $this->repositoryName,
+			);
+			foreach ($variables as $name => $value) {
+				$url = str_replace('/:' . $name, '/' . urlencode($value), $url);
+			}
+			$url = 'https://api.github.com' . $url;
+
+			if ( !empty($queryParams) ) {
+				$url = add_query_arg($queryParams, $url);
+			}
+
+			return $url;
+		}
+
+		/**
+		 * Get the contents of a file from a specific branch or tag.
+		 *
+		 * @param string $path File name.
+		 * @param string $ref
+		 * @return null|string Either the contents of the file, or null if the file doesn't exist or there's an error.
+		 */
+		public function getRemoteFile($path, $ref = 'master') {
+			$apiUrl = '/repos/:user/:repo/contents/' . $path;
+			$response = $this->api($apiUrl, array('ref' => $ref));
+
+			if ( is_wp_error($response) || !isset($response->content) || ($response->encoding !== 'base64') ) {
+				return null;
+			}
+			return base64_decode($response->content);
+		}
+
+		/**
+		 * Generate a URL to download a ZIP archive of the specified branch/tag/etc.
+		 *
+		 * @param string $ref
+		 * @return string
+		 */
+		public function buildArchiveDownloadUrl($ref = 'master') {
+			$url = sprintf(
+				'https://api.github.com/repos/%1$s/%2$s/zipball/%3$s',
+				urlencode($this->userName),
+				urlencode($this->repositoryName),
+				urlencode($ref)
+			);
+			return $url;
+		}
+
+		/**
+		 * Get a specific tag.
+		 *
+		 * @param string $tagName
+		 * @return void
+		 */
+		public function getTag($tagName) {
+			//The current GitHub update checker doesn't use getTag, so I didn't bother to implement it.
+			throw new \LogicException('The ' . __METHOD__ . ' method is not implemented and should not be used.');
+		}
+
+		public function setAuthentication($credentials) {
+			parent::setAuthentication($credentials);
+			$this->accessToken = is_string($credentials) ? $credentials : null;
+
+			//Optimization: Instead of filtering all HTTP requests, let's do it only when
+			//WordPress is about to download an update.
+			add_filter('upgrader_pre_download', array($this, 'addHttpRequestFilter'), 10, 1); //WP 3.7+
+		}
+
+		protected function getUpdateDetectionStrategies($configBranch) {
+			$strategies = array();
+
+			if ( $configBranch === 'master' || $configBranch === 'main') {
+				//Use the latest release.
+				$strategies[self::STRATEGY_LATEST_RELEASE] = array($this, 'getLatestRelease');
+				//Failing that, use the tag with the highest version number.
+				$strategies[self::STRATEGY_LATEST_TAG] = array($this, 'getLatestTag');
+			}
+
+			//Alternatively, just use the branch itself.
+			$strategies[self::STRATEGY_BRANCH] = function () use ($configBranch) {
+				return $this->getBranch($configBranch);
+			};
+
+			return $strategies;
+		}
+
+		/**
+		 * Get the unchanging part of a release asset URL. Used to identify download attempts.
+		 *
+		 * @return string
+		 */
+		protected function getAssetApiBaseUrl() {
+			return sprintf(
+				'//api.github.com/repos/%1$s/%2$s/releases/assets/',
+				$this->userName,
+				$this->repositoryName
+			);
+		}
+
+		protected function getFilterableAssetName($releaseAsset) {
+			if ( isset($releaseAsset->name) ) {
+				return $releaseAsset->name;
+			}
+			return null;
+		}
+
+		/**
+		 * @param bool $result
+		 * @return bool
+		 * @internal
+		 */
+		public function addHttpRequestFilter($result) {
+			if ( !$this->downloadFilterAdded && $this->isAuthenticationEnabled() ) {
+				//phpcs:ignore WordPressVIPMinimum.Hooks.RestrictedHooks.http_request_args -- The callback doesn't change the timeout.
+				add_filter('http_request_args', array($this, 'setUpdateDownloadHeaders'), 10, 2);
+				add_action('requests-requests.before_redirect', array($this, 'removeAuthHeaderFromRedirects'), 10, 4);
+				$this->downloadFilterAdded = true;
+			}
+			return $result;
+		}
+
+		/**
+		 * Set the HTTP headers that are necessary to download updates from private repositories.
+		 *
+		 * See GitHub docs:
+		 *
+		 * @link https://developer.github.com/v3/repos/releases/#get-a-single-release-asset
+		 * @link https://developer.github.com/v3/auth/#basic-authentication
+		 *
+		 * @internal
+		 * @param array $requestArgs
+		 * @param string $url
+		 * @return array
+		 */
+		public function setUpdateDownloadHeaders($requestArgs, $url = '') {
+			//Is WordPress trying to download one of our release assets?
+			if ( $this->releaseAssetsEnabled && (strpos($url, $this->getAssetApiBaseUrl()) !== false) ) {
+				$requestArgs['headers']['Accept'] = 'application/octet-stream';
+			}
+			//Use Basic authentication, but only if the download is from our repository.
+			$repoApiBaseUrl = $this->buildApiUrl('/repos/:user/:repo/', array());
+			if ( $this->isAuthenticationEnabled() && (strpos($url, $repoApiBaseUrl)) === 0 ) {
+				$requestArgs['headers']['Authorization'] = $this->getAuthorizationHeader();
+			}
+			return $requestArgs;
+		}
+
+		/**
+		 * When following a redirect, the Requests library will automatically forward
+		 * the authorization header to other hosts. We don't want that because it breaks
+		 * AWS downloads and can leak authorization information.
+		 *
+		 * @param string $location
+		 * @param array $headers
+		 * @internal
+		 */
+		public function removeAuthHeaderFromRedirects(&$location, &$headers) {
+			$repoApiBaseUrl = $this->buildApiUrl('/repos/:user/:repo/', array());
+			if ( strpos($location, $repoApiBaseUrl) === 0 ) {
+				return; //This request is going to GitHub, so it's fine.
+			}
+			//Remove the header.
+			if ( isset($headers['Authorization']) ) {
+				unset($headers['Authorization']);
+			}
+		}
+
+		/**
+		 * Generate the value of the "Authorization" header.
+		 *
+		 * @return string
+		 */
+		protected function getAuthorizationHeader() {
+			return 'Basic ' . base64_encode($this->userName . ':' . $this->accessToken);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/GitLabApi.php

@@ -0,0 +1,414 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !class_exists(GitLabApi::class, false) ):
+
+	class GitLabApi extends Api {
+		use ReleaseAssetSupport;
+		use ReleaseFilteringFeature;
+
+		/**
+		 * @var string GitLab username.
+		 */
+		protected $userName;
+
+		/**
+		 * @var string GitLab server host.
+		 */
+		protected $repositoryHost;
+
+		/**
+		 * @var string Protocol used by this GitLab server: "http" or "https".
+		 */
+		protected $repositoryProtocol = 'https';
+
+		/**
+		 * @var string GitLab repository name.
+		 */
+		protected $repositoryName;
+
+		/**
+		 * @var string GitLab authentication token. Optional.
+		 */
+		protected $accessToken;
+
+		/**
+		 * @deprecated
+		 * @var bool No longer used.
+		 */
+		protected $releasePackageEnabled = false;
+
+		public function __construct($repositoryUrl, $accessToken = null, $subgroup = null) {
+			//Parse the repository host to support custom hosts.
+			$port = wp_parse_url($repositoryUrl, PHP_URL_PORT);
+			if ( !empty($port) ) {
+				$port = ':' . $port;
+			}
+			$this->repositoryHost = wp_parse_url($repositoryUrl, PHP_URL_HOST) . $port;
+
+			if ( $this->repositoryHost !== 'gitlab.com' ) {
+				$this->repositoryProtocol = wp_parse_url($repositoryUrl, PHP_URL_SCHEME);
+			}
+
+			//Find the repository information
+			$path = wp_parse_url($repositoryUrl, PHP_URL_PATH);
+			if ( preg_match('@^/?(?P<username>[^/]+?)/(?P<repository>[^/#?&]+?)/?$@', $path, $matches) ) {
+				$this->userName = $matches['username'];
+				$this->repositoryName = $matches['repository'];
+			} elseif ( ($this->repositoryHost === 'gitlab.com') ) {
+				//This is probably a repository in a subgroup, e.g. "/organization/category/repo".
+				$parts = explode('/', trim($path, '/'));
+				if ( count($parts) < 3 ) {
+					throw new \InvalidArgumentException('Invalid GitLab.com repository URL: "' . $repositoryUrl . '"');
+				}
+				$lastPart = array_pop($parts);
+				$this->userName = implode('/', $parts);
+				$this->repositoryName = $lastPart;
+			} else {
+				//There could be subgroups in the URL:  gitlab.domain.com/group/subgroup/subgroup2/repository
+				if ( $subgroup !== null ) {
+					$path = str_replace(trailingslashit($subgroup), '', $path);
+				}
+
+				//This is not a traditional url, it could be gitlab is in a deeper subdirectory.
+				//Get the path segments.
+				$segments = explode('/', untrailingslashit(ltrim($path, '/')));
+
+				//We need at least /user-name/repository-name/
+				if ( count($segments) < 2 ) {
+					throw new \InvalidArgumentException('Invalid GitLab repository URL: "' . $repositoryUrl . '"');
+				}
+
+				//Get the username and repository name.
+				$usernameRepo = array_splice($segments, -2, 2);
+				$this->userName = $usernameRepo[0];
+				$this->repositoryName = $usernameRepo[1];
+
+				//Append the remaining segments to the host if there are segments left.
+				if ( count($segments) > 0 ) {
+					$this->repositoryHost = trailingslashit($this->repositoryHost) . implode('/', $segments);
+				}
+
+				//Add subgroups to username.
+				if ( $subgroup !== null ) {
+					$this->userName = $usernameRepo[0] . '/' . untrailingslashit($subgroup);
+				}
+			}
+
+			parent::__construct($repositoryUrl, $accessToken);
+		}
+
+		/**
+		 * Get the latest release from GitLab.
+		 *
+		 * @return Reference|null
+		 */
+		public function getLatestRelease() {
+			$releases = $this->api('/:id/releases', array('per_page' => $this->releaseFilterMaxReleases));
+			if ( is_wp_error($releases) || empty($releases) || !is_array($releases) ) {
+				return null;
+			}
+
+			foreach ($releases as $release) {
+				if (
+					//Skip invalid/unsupported releases.
+					!is_object($release)
+					|| !isset($release->tag_name)
+					//Skip upcoming releases.
+					|| (
+						!empty($release->upcoming_release)
+						&& $this->shouldSkipPreReleases()
+					)
+				) {
+					continue;
+				}
+
+				$versionNumber = ltrim($release->tag_name, 'v'); //Remove the "v" prefix from "v1.2.3".
+
+				//Apply custom filters.
+				if ( !$this->matchesCustomReleaseFilter($versionNumber, $release) ) {
+					continue;
+				}
+
+				$downloadUrl = $this->findReleaseDownloadUrl($release);
+				if ( empty($downloadUrl) ) {
+					//The latest release doesn't have valid download URL.
+					return null;
+				}
+
+				if ( !empty($this->accessToken) ) {
+					$downloadUrl = add_query_arg('private_token', $this->accessToken, $downloadUrl);
+				}
+
+				return new Reference(array(
+					'name'        => $release->tag_name,
+					'version'     => $versionNumber,
+					'downloadUrl' => $downloadUrl,
+					'updated'     => $release->released_at,
+					'apiResponse' => $release,
+				));
+			}
+
+			return null;
+		}
+
+		/**
+		 * @param object $release
+		 * @return string|null
+		 */
+		protected function findReleaseDownloadUrl($release) {
+			if ( $this->releaseAssetsEnabled ) {
+				if ( isset($release->assets, $release->assets->links) ) {
+					//Use the first asset link where the URL matches the filter.
+					foreach ($release->assets->links as $link) {
+						if ( $this->matchesAssetFilter($link) ) {
+							return $link->url;
+						}
+					}
+				}
+
+				if ( $this->releaseAssetPreference === Api::REQUIRE_RELEASE_ASSETS ) {
+					//Falling back to source archives is not allowed, so give up.
+					return null;
+				}
+			}
+
+			//Use the first source code archive that's in ZIP format.
+			foreach ($release->assets->sources as $source) {
+				if ( isset($source->format) && ($source->format === 'zip') ) {
+					return $source->url;
+				}
+			}
+
+			return null;
+		}
+
+		/**
+		 * Get the tag that looks like the highest version number.
+		 *
+		 * @return Reference|null
+		 */
+		public function getLatestTag() {
+			$tags = $this->api('/:id/repository/tags');
+			if ( is_wp_error($tags) || empty($tags) || !is_array($tags) ) {
+				return null;
+			}
+
+			$versionTags = $this->sortTagsByVersion($tags);
+			if ( empty($versionTags) ) {
+				return null;
+			}
+
+			$tag = $versionTags[0];
+			return new Reference(array(
+				'name'        => $tag->name,
+				'version'     => ltrim($tag->name, 'v'),
+				'downloadUrl' => $this->buildArchiveDownloadUrl($tag->name),
+				'apiResponse' => $tag,
+			));
+		}
+
+		/**
+		 * Get a branch by name.
+		 *
+		 * @param string $branchName
+		 * @return null|Reference
+		 */
+		public function getBranch($branchName) {
+			$branch = $this->api('/:id/repository/branches/' . $branchName);
+			if ( is_wp_error($branch) || empty($branch) ) {
+				return null;
+			}
+
+			$reference = new Reference(array(
+				'name'        => $branch->name,
+				'downloadUrl' => $this->buildArchiveDownloadUrl($branch->name),
+				'apiResponse' => $branch,
+			));
+
+			if ( isset($branch->commit, $branch->commit->committed_date) ) {
+				$reference->updated = $branch->commit->committed_date;
+			}
+
+			return $reference;
+		}
+
+		/**
+		 * Get the timestamp of the latest commit that changed the specified branch or tag.
+		 *
+		 * @param string $ref Reference name (e.g. branch or tag).
+		 * @return string|null
+		 */
+		public function getLatestCommitTime($ref) {
+			$commits = $this->api('/:id/repository/commits/', array('ref_name' => $ref));
+			if ( is_wp_error($commits) || !is_array($commits) || !isset($commits[0]) ) {
+				return null;
+			}
+
+			return $commits[0]->committed_date;
+		}
+
+		/**
+		 * Perform a GitLab API request.
+		 *
+		 * @param string $url
+		 * @param array $queryParams
+		 * @return mixed|\WP_Error
+		 */
+		protected function api($url, $queryParams = array()) {
+			$baseUrl = $url;
+			$url = $this->buildApiUrl($url, $queryParams);
+
+			$options = array('timeout' => wp_doing_cron() ? 10 : 3);
+			if ( !empty($this->httpFilterName) ) {
+				$options = apply_filters($this->httpFilterName, $options);
+			}
+
+			$response = wp_remote_get($url, $options);
+			if ( is_wp_error($response) ) {
+				do_action('puc_api_error', $response, null, $url, $this->slug);
+				return $response;
+			}
+
+			$code = wp_remote_retrieve_response_code($response);
+			$body = wp_remote_retrieve_body($response);
+			if ( $code === 200 ) {
+				return json_decode($body);
+			}
+
+			$error = new \WP_Error(
+				'puc-gitlab-http-error',
+				sprintf('GitLab API error. URL: "%s",  HTTP status code: %d.', $baseUrl, $code)
+			);
+			do_action('puc_api_error', $error, $response, $url, $this->slug);
+
+			return $error;
+		}
+
+		/**
+		 * Build a fully qualified URL for an API request.
+		 *
+		 * @param string $url
+		 * @param array $queryParams
+		 * @return string
+		 */
+		protected function buildApiUrl($url, $queryParams) {
+			$variables = array(
+				'user' => $this->userName,
+				'repo' => $this->repositoryName,
+				'id'   => $this->userName . '/' . $this->repositoryName,
+			);
+
+			foreach ($variables as $name => $value) {
+				$url = str_replace("/:{$name}", '/' . urlencode($value), $url);
+			}
+
+			$url = substr($url, 1);
+			$url = sprintf('%1$s://%2$s/api/v4/projects/%3$s', $this->repositoryProtocol, $this->repositoryHost, $url);
+
+			if ( !empty($this->accessToken) ) {
+				$queryParams['private_token'] = $this->accessToken;
+			}
+
+			if ( !empty($queryParams) ) {
+				$url = add_query_arg($queryParams, $url);
+			}
+
+			return $url;
+		}
+
+		/**
+		 * Get the contents of a file from a specific branch or tag.
+		 *
+		 * @param string $path File name.
+		 * @param string $ref
+		 * @return null|string Either the contents of the file, or null if the file doesn't exist or there's an error.
+		 */
+		public function getRemoteFile($path, $ref = 'master') {
+			$response = $this->api('/:id/repository/files/' . $path, array('ref' => $ref));
+			if ( is_wp_error($response) || !isset($response->content) || $response->encoding !== 'base64' ) {
+				return null;
+			}
+
+			return base64_decode($response->content);
+		}
+
+		/**
+		 * Generate a URL to download a ZIP archive of the specified branch/tag/etc.
+		 *
+		 * @param string $ref
+		 * @return string
+		 */
+		public function buildArchiveDownloadUrl($ref = 'master') {
+			$url = sprintf(
+				'%1$s://%2$s/api/v4/projects/%3$s/repository/archive.zip',
+				$this->repositoryProtocol,
+				$this->repositoryHost,
+				urlencode($this->userName . '/' . $this->repositoryName)
+			);
+			$url = add_query_arg('sha', urlencode($ref), $url);
+
+			if ( !empty($this->accessToken) ) {
+				$url = add_query_arg('private_token', $this->accessToken, $url);
+			}
+
+			return $url;
+		}
+
+		/**
+		 * Get a specific tag.
+		 *
+		 * @param string $tagName
+		 * @return void
+		 */
+		public function getTag($tagName) {
+			throw new \LogicException('The ' . __METHOD__ . ' method is not implemented and should not be used.');
+		}
+
+		protected function getUpdateDetectionStrategies($configBranch) {
+			$strategies = array();
+
+			if ( ($configBranch === 'main') || ($configBranch === 'master') ) {
+				$strategies[self::STRATEGY_LATEST_RELEASE] = array($this, 'getLatestRelease');
+				$strategies[self::STRATEGY_LATEST_TAG] = array($this, 'getLatestTag');
+			}
+
+			$strategies[self::STRATEGY_BRANCH] = function () use ($configBranch) {
+				return $this->getBranch($configBranch);
+			};
+
+			return $strategies;
+		}
+
+		public function setAuthentication($credentials) {
+			parent::setAuthentication($credentials);
+			$this->accessToken = is_string($credentials) ? $credentials : null;
+		}
+
+		/**
+		 * Use release assets that link to GitLab generic packages (e.g. .zip files)
+		 * instead of automatically generated source archives.
+		 *
+		 * This is included for backwards compatibility with older versions of PUC.
+		 *
+		 * @return void
+		 * @deprecated   Use enableReleaseAssets() instead.
+		 * @noinspection PhpUnused -- Public API
+		 */
+		public function enableReleasePackages() {
+			$this->enableReleaseAssets(
+			/** @lang RegExp */ '/\.zip($|[?&#])/i',
+				Api::REQUIRE_RELEASE_ASSETS
+			);
+		}
+
+		protected function getFilterableAssetName($releaseAsset) {
+			if ( isset($releaseAsset->url) ) {
+				return $releaseAsset->url;
+			}
+			return null;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/PluginUpdateChecker.php

@@ -0,0 +1,275 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Plugin;
+
+if ( !class_exists(PluginUpdateChecker::class, false) ):
+
+	class PluginUpdateChecker extends Plugin\UpdateChecker implements BaseChecker {
+		use VcsCheckerMethods;
+
+		/**
+		 * PluginUpdateChecker constructor.
+		 *
+		 * @param Api $api
+		 * @param string $pluginFile
+		 * @param string $slug
+		 * @param int $checkPeriod
+		 * @param string $optionName
+		 * @param string $muPluginFile
+		 */
+		public function __construct($api, $pluginFile, $slug = '', $checkPeriod = 12, $optionName = '', $muPluginFile = '') {
+			$this->api = $api;
+
+			parent::__construct($api->getRepositoryUrl(), $pluginFile, $slug, $checkPeriod, $optionName, $muPluginFile);
+
+			$this->api->setHttpFilterName($this->getUniqueName('request_info_options'));
+			$this->api->setStrategyFilterName($this->getUniqueName('vcs_update_detection_strategies'));
+			$this->api->setSlug($this->slug);
+		}
+
+		public function requestInfo($unusedParameter = null) {
+			//We have to make several remote API requests to gather all the necessary info
+			//which can take a while on slow networks.
+			if ( function_exists('set_time_limit') ) {
+				@set_time_limit(60);
+			}
+
+			$api = $this->api;
+			$api->setLocalDirectory($this->package->getAbsoluteDirectoryPath());
+
+			$info = new Plugin\PluginInfo();
+			$info->filename = $this->pluginFile;
+			$info->slug = $this->slug;
+
+			$this->setInfoFromHeader($this->package->getPluginHeader(), $info);
+			$this->setIconsFromLocalAssets($info);
+			$this->setBannersFromLocalAssets($info);
+
+			//Pick a branch or tag.
+			$updateSource = $api->chooseReference($this->branch);
+			if ( $updateSource ) {
+				$ref = $updateSource->name;
+				$info->version = $updateSource->version;
+				$info->last_updated = $updateSource->updated;
+				$info->download_url = $updateSource->downloadUrl;
+
+				if ( !empty($updateSource->changelog) ) {
+					$info->sections['changelog'] = $updateSource->changelog;
+				}
+				if ( isset($updateSource->downloadCount) ) {
+					$info->downloaded = $updateSource->downloadCount;
+				}
+			} else {
+				//There's probably a network problem or an authentication error.
+				do_action(
+					'puc_api_error',
+					new \WP_Error(
+						'puc-no-update-source',
+						'Could not retrieve version information from the repository. '
+						. 'This usually means that the update checker either can\'t connect '
+						. 'to the repository or it\'s configured incorrectly.'
+					),
+					null, null, $this->slug
+				);
+				return null;
+			}
+
+			//Get headers from the main plugin file in this branch/tag. Its "Version" header and other metadata
+			//are what the WordPress install will actually see after upgrading, so they take precedence over releases/tags.
+			$mainPluginFile = basename($this->pluginFile);
+			$remotePlugin = $api->getRemoteFile($mainPluginFile, $ref);
+			if ( !empty($remotePlugin) ) {
+				$remoteHeader = $this->package->getFileHeader($remotePlugin);
+				$this->setInfoFromHeader($remoteHeader, $info);
+			}
+
+			//Sanity check: Reject updates that don't have a version number.
+			//This can happen when we're using a branch, and we either fail to retrieve the main plugin
+			//file or the file doesn't have a "Version" header.
+			if ( empty($info->version) ) {
+				do_action(
+					'puc_api_error',
+					new \WP_Error(
+						'puc-no-plugin-version',
+						'Could not find the version number in the repository.'
+					),
+					null, null, $this->slug
+				);
+				return null;
+			}
+
+			//Try parsing readme.txt. If it's formatted according to WordPress.org standards, it will contain
+			//a lot of useful information like the required/tested WP version, changelog, and so on.
+			if ( $this->readmeTxtExistsLocally() ) {
+				$this->setInfoFromRemoteReadme($ref, $info);
+			}
+
+			//The changelog might be in a separate file.
+			if ( empty($info->sections['changelog']) ) {
+				$info->sections['changelog'] = $api->getRemoteChangelog($ref, $this->package->getAbsoluteDirectoryPath());
+				if ( empty($info->sections['changelog']) ) {
+					$info->sections['changelog'] = __('There is no changelog available.', 'plugin-update-checker');
+				}
+			}
+
+			if ( empty($info->last_updated) ) {
+				//Fetch the latest commit that changed the tag or branch and use it as the "last_updated" date.
+				$latestCommitTime = $api->getLatestCommitTime($ref);
+				if ( $latestCommitTime !== null ) {
+					$info->last_updated = $latestCommitTime;
+				}
+			}
+
+			$info = apply_filters($this->getUniqueName('request_info_result'), $info, null);
+			return $info;
+		}
+
+		/**
+		 * Check if the currently installed version has a readme.txt file.
+		 *
+		 * @return bool
+		 */
+		protected function readmeTxtExistsLocally() {
+			return $this->package->fileExists($this->api->getLocalReadmeName());
+		}
+
+		/**
+		 * Copy plugin metadata from a file header to a Plugin Info object.
+		 *
+		 * @param array $fileHeader
+		 * @param Plugin\PluginInfo $pluginInfo
+		 */
+		protected function setInfoFromHeader($fileHeader, $pluginInfo) {
+			$headerToPropertyMap = array(
+				'Version' => 'version',
+				'Name' => 'name',
+				'PluginURI' => 'homepage',
+				'Author' => 'author',
+				'AuthorName' => 'author',
+				'AuthorURI' => 'author_homepage',
+
+				'Requires WP' => 'requires',
+				'Tested WP' => 'tested',
+				'Requires at least' => 'requires',
+				'Tested up to' => 'tested',
+
+				'Requires PHP' => 'requires_php',
+			);
+			foreach ($headerToPropertyMap as $headerName => $property) {
+				if ( isset($fileHeader[$headerName]) && !empty($fileHeader[$headerName]) ) {
+					$pluginInfo->$property = $fileHeader[$headerName];
+				}
+			}
+
+			if ( !empty($fileHeader['Description']) ) {
+				$pluginInfo->sections['description'] = $fileHeader['Description'];
+			}
+		}
+
+		/**
+		 * Copy plugin metadata from the remote readme.txt file.
+		 *
+		 * @param string $ref GitHub tag or branch where to look for the readme.
+		 * @param Plugin\PluginInfo $pluginInfo
+		 */
+		protected function setInfoFromRemoteReadme($ref, $pluginInfo) {
+			$readme = $this->api->getRemoteReadme($ref);
+			if ( empty($readme) ) {
+				return;
+			}
+
+			if ( isset($readme['sections']) ) {
+				$pluginInfo->sections = array_merge($pluginInfo->sections, $readme['sections']);
+			}
+			if ( !empty($readme['tested_up_to']) ) {
+				$pluginInfo->tested = $readme['tested_up_to'];
+			}
+			if ( !empty($readme['requires_at_least']) ) {
+				$pluginInfo->requires = $readme['requires_at_least'];
+			}
+			if ( !empty($readme['requires_php']) ) {
+				$pluginInfo->requires_php = $readme['requires_php'];
+			}
+
+			if ( isset($readme['upgrade_notice'], $readme['upgrade_notice'][$pluginInfo->version]) ) {
+				$pluginInfo->upgrade_notice = $readme['upgrade_notice'][$pluginInfo->version];
+			}
+		}
+
+		/**
+		 * Add icons from the currently installed version to a Plugin Info object.
+		 *
+		 * The icons should be in a subdirectory named "assets". Supported image formats
+		 * and file names are described here:
+		 * @link https://developer.wordpress.org/plugins/wordpress-org/plugin-assets/#plugin-icons
+		 *
+		 * @param Plugin\PluginInfo $pluginInfo
+		 */
+		protected function setIconsFromLocalAssets($pluginInfo) {
+			$icons = $this->getLocalAssetUrls(array(
+				'icon.svg'         => 'svg',
+				'icon-256x256.png' => '2x',
+				'icon-256x256.jpg' => '2x',
+				'icon-128x128.png' => '1x',
+				'icon-128x128.jpg' => '1x',
+			));
+
+			if ( !empty($icons) ) {
+				//The "default" key seems to be used only as last-resort fallback in WP core (5.8/5.9),
+				//but we'll set it anyway in case some code somewhere needs it.
+				reset($icons);
+				$firstKey = key($icons);
+				$icons['default'] = $icons[$firstKey];
+
+				$pluginInfo->icons = $icons;
+			}
+		}
+
+		/**
+		 * Add banners from the currently installed version to a Plugin Info object.
+		 *
+		 * The banners should be in a subdirectory named "assets". Supported image formats
+		 * and file names are described here:
+		 * @link https://developer.wordpress.org/plugins/wordpress-org/plugin-assets/#plugin-headers
+		 *
+		 * @param Plugin\PluginInfo $pluginInfo
+		 */
+		protected function setBannersFromLocalAssets($pluginInfo) {
+			$banners = $this->getLocalAssetUrls(array(
+				'banner-772x250.png' => 'high',
+				'banner-772x250.jpg' => 'high',
+				'banner-1544x500.png' => 'low',
+				'banner-1544x500.jpg' => 'low',
+			));
+
+			if ( !empty($banners) ) {
+				$pluginInfo->banners = $banners;
+			}
+		}
+
+		/**
+		 * @param array<string, string> $filesToKeys
+		 * @return array<string, string>
+		 */
+		protected function getLocalAssetUrls($filesToKeys) {
+			$assetDirectory = $this->package->getAbsoluteDirectoryPath() . DIRECTORY_SEPARATOR . 'assets';
+			if ( !is_dir($assetDirectory) ) {
+				return array();
+			}
+			$assetBaseUrl = trailingslashit(plugins_url('', $assetDirectory . '/imaginary.file'));
+
+			$foundAssets = array();
+			foreach ($filesToKeys as $fileName => $key) {
+				$fullBannerPath = $assetDirectory . DIRECTORY_SEPARATOR . $fileName;
+				if ( !isset($icons[$key]) && is_file($fullBannerPath) ) {
+					$foundAssets[$key] = $assetBaseUrl . $fileName;
+				}
+			}
+
+			return $foundAssets;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/Reference.php

@@ -0,0 +1,51 @@
+<?php
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !class_exists(Reference::class, false) ):
+
+	/**
+	 * This class represents a VCS branch or tag. It's intended as a read only, short-lived container
+	 * that only exists to provide a limited degree of type checking.
+	 *
+	 * @property string $name
+	 * @property string|null version
+	 * @property string $downloadUrl
+	 * @property string $updated
+	 *
+	 * @property string|null $changelog
+	 * @property int|null $downloadCount
+	 */
+	class Reference {
+		private $properties = array();
+
+		public function __construct($properties = array()) {
+			$this->properties = $properties;
+		}
+
+		/**
+		 * @param string $name
+		 * @return mixed|null
+		 */
+		public function __get($name) {
+			return array_key_exists($name, $this->properties) ? $this->properties[$name] : null;
+		}
+
+		/**
+		 * @param string $name
+		 * @param mixed $value
+		 */
+		public function __set($name, $value) {
+			$this->properties[$name] = $value;
+		}
+
+		/**
+		 * @param string $name
+		 * @return bool
+		 */
+		public function __isset($name) {
+			return isset($this->properties[$name]);
+		}
+
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/ReleaseAssetSupport.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !trait_exists(ReleaseAssetSupport::class, false) ) :
+
+	trait ReleaseAssetSupport {
+		/**
+		 * @var bool Whether to download release assets instead of the auto-generated
+		 *           source code archives.
+		 */
+		protected $releaseAssetsEnabled = false;
+
+		/**
+		 * @var string|null Regular expression that's used to filter release assets
+		 *                  by file name or URL. Optional.
+		 */
+		protected $assetFilterRegex = null;
+
+		/**
+		 * How to handle releases that don't have any matching release assets.
+		 *
+		 * @var int
+		 */
+		protected $releaseAssetPreference = Api::PREFER_RELEASE_ASSETS;
+
+		/**
+		 * Enable updating via release assets.
+		 *
+		 * If the latest release contains no usable assets, the update checker
+		 * will fall back to using the automatically generated ZIP archive.
+		 *
+		 * @param string|null $nameRegex Optional. Use only those assets where
+		 *                               the file name or URL matches this regex.
+		 * @param int $preference Optional. How to handle releases that don't have
+		 *                        any matching release assets.
+		 */
+		public function enableReleaseAssets($nameRegex = null, $preference = Api::PREFER_RELEASE_ASSETS) {
+			$this->releaseAssetsEnabled = true;
+			$this->assetFilterRegex = $nameRegex;
+			$this->releaseAssetPreference = $preference;
+		}
+
+		/**
+		 * Disable release assets.
+		 *
+		 * @return void
+		 * @noinspection PhpUnused -- Public API
+		 */
+		public function disableReleaseAssets() {
+			$this->releaseAssetsEnabled = false;
+			$this->assetFilterRegex = null;
+		}
+
+		/**
+		 * Does the specified asset match the name regex?
+		 *
+		 * @param mixed $releaseAsset Data type and structure depend on the host/API.
+		 * @return bool
+		 */
+		protected function matchesAssetFilter($releaseAsset) {
+			if ( $this->assetFilterRegex === null ) {
+				//The default is to accept all assets.
+				return true;
+			}
+
+			$name = $this->getFilterableAssetName($releaseAsset);
+			if ( !is_string($name) ) {
+				return false;
+			}
+			return (bool)preg_match($this->assetFilterRegex, $releaseAsset->name);
+		}
+
+		/**
+		 * Get the part of asset data that will be checked against the filter regex.
+		 *
+		 * @param mixed $releaseAsset
+		 * @return string|null
+		 */
+		abstract protected function getFilterableAssetName($releaseAsset);
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/ReleaseFilteringFeature.php

@@ -0,0 +1,108 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !trait_exists(ReleaseFilteringFeature::class, false) ) :
+
+	trait ReleaseFilteringFeature {
+		/**
+		 * @var callable|null
+		 */
+		protected $releaseFilterCallback = null;
+		/**
+		 * @var int
+		 */
+		protected $releaseFilterMaxReleases = 1;
+		/**
+		 * @var string One of the Api::RELEASE_FILTER_* constants.
+		 */
+		protected $releaseFilterByType = Api::RELEASE_FILTER_SKIP_PRERELEASE;
+
+		/**
+		 * Set a custom release filter.
+		 *
+		 * Setting a new filter will override the old filter, if any.
+		 *
+		 * @param callable $callback A callback that accepts a version number and a release
+		 *                           object, and returns a boolean.
+		 * @param int $releaseTypes  One of the Api::RELEASE_FILTER_* constants.
+		 * @param int $maxReleases   Optional. The maximum number of recent releases to examine
+		 *                           when trying to find a release that matches the filter. 1 to 100.
+		 * @return $this
+		 */
+		public function setReleaseFilter(
+			$callback,
+			$releaseTypes = Api::RELEASE_FILTER_SKIP_PRERELEASE,
+			$maxReleases = 20
+		) {
+			if ( $maxReleases > 100 ) {
+				throw new \InvalidArgumentException(sprintf(
+					'The max number of releases is too high (%d). It must be 100 or less.',
+					$maxReleases
+				));
+			} else if ( $maxReleases < 1 ) {
+				throw new \InvalidArgumentException(sprintf(
+					'The max number of releases is too low (%d). It must be at least 1.',
+					$maxReleases
+				));
+			}
+
+			$this->releaseFilterCallback = $callback;
+			$this->releaseFilterByType = $releaseTypes;
+			$this->releaseFilterMaxReleases = $maxReleases;
+			return $this;
+		}
+
+		/**
+		 * Filter releases by their version number.
+		 *
+		 * @param string $regex A regular expression. The release version number must match this regex.
+		 * @param int $releaseTypes
+		 * @param int $maxReleasesToExamine
+		 * @return $this
+		 * @noinspection PhpUnused -- Public API
+		 */
+		public function setReleaseVersionFilter(
+			$regex,
+			$releaseTypes = Api::RELEASE_FILTER_SKIP_PRERELEASE,
+			$maxReleasesToExamine = 20
+		) {
+			return $this->setReleaseFilter(
+				function ($versionNumber) use ($regex) {
+					return (preg_match($regex, $versionNumber) === 1);
+				},
+				$releaseTypes,
+				$maxReleasesToExamine
+			);
+		}
+
+		/**
+		 * @param string $versionNumber The detected release version number.
+		 * @param object $releaseObject Varies depending on the host/API.
+		 * @return bool
+		 */
+		protected function matchesCustomReleaseFilter($versionNumber, $releaseObject) {
+			if ( !is_callable($this->releaseFilterCallback) ) {
+				return true; //No custom filter.
+			}
+			return call_user_func($this->releaseFilterCallback, $versionNumber, $releaseObject);
+		}
+
+		/**
+		 * @return bool
+		 */
+		protected function shouldSkipPreReleases() {
+			//Maybe this could be a bitfield in the future, if we need to support
+			//more release types.
+			return ($this->releaseFilterByType !== Api::RELEASE_FILTER_ALL);
+		}
+
+		/**
+		 * @return bool
+		 */
+		protected function hasCustomReleaseFilter() {
+			return isset($this->releaseFilterCallback) && is_callable($this->releaseFilterCallback);
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/ThemeUpdateChecker.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+use YahnisElsts\PluginUpdateChecker\v5p3\Theme;
+use YahnisElsts\PluginUpdateChecker\v5p3\Utils;
+
+if ( !class_exists(ThemeUpdateChecker::class, false) ):
+
+	class ThemeUpdateChecker extends Theme\UpdateChecker implements BaseChecker {
+		use VcsCheckerMethods;
+
+		/**
+		 * ThemeUpdateChecker constructor.
+		 *
+		 * @param Api $api
+		 * @param null $stylesheet
+		 * @param null $customSlug
+		 * @param int $checkPeriod
+		 * @param string $optionName
+		 */
+		public function __construct($api, $stylesheet = null, $customSlug = null, $checkPeriod = 12, $optionName = '') {
+			$this->api = $api;
+
+			parent::__construct($api->getRepositoryUrl(), $stylesheet, $customSlug, $checkPeriod, $optionName);
+
+			$this->api->setHttpFilterName($this->getUniqueName('request_update_options'));
+			$this->api->setStrategyFilterName($this->getUniqueName('vcs_update_detection_strategies'));
+			$this->api->setSlug($this->slug);
+		}
+
+		public function requestUpdate() {
+			$api = $this->api;
+			$api->setLocalDirectory($this->package->getAbsoluteDirectoryPath());
+
+			$update = new Theme\Update();
+			$update->slug = $this->slug;
+
+			//Figure out which reference (tag or branch) we'll use to get the latest version of the theme.
+			$updateSource = $api->chooseReference($this->branch);
+			if ( $updateSource ) {
+				$ref = $updateSource->name;
+				$update->download_url = $updateSource->downloadUrl;
+			} else {
+				do_action(
+					'puc_api_error',
+					new \WP_Error(
+						'puc-no-update-source',
+						'Could not retrieve version information from the repository. '
+						. 'This usually means that the update checker either can\'t connect '
+						. 'to the repository or it\'s configured incorrectly.'
+					),
+					null, null, $this->slug
+				);
+				$ref = $this->branch;
+			}
+
+			//Get headers from the main stylesheet in this branch/tag. Its "Version" header and other metadata
+			//are what the WordPress install will actually see after upgrading, so they take precedence over releases/tags.
+			$remoteHeader = $this->package->getFileHeader($api->getRemoteFile('style.css', $ref));
+			$update->version = Utils::findNotEmpty(array(
+				$remoteHeader['Version'],
+				Utils::get($updateSource, 'version'),
+			));
+
+			//The details URL defaults to the Theme URI header or the repository URL.
+			$update->details_url = Utils::findNotEmpty(array(
+				$remoteHeader['ThemeURI'],
+				$this->package->getHeaderValue('ThemeURI'),
+				$this->metadataUrl,
+			));
+
+			if ( empty($update->version) ) {
+				//It looks like we didn't find a valid update after all.
+				$update = null;
+			}
+
+			$update = $this->filterUpdateResult($update);
+			return $update;
+		}
+	}
+
+endif;

lib/plugin-update-checker/Puc/v5p3/Vcs/VcsCheckerMethods.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace YahnisElsts\PluginUpdateChecker\v5p3\Vcs;
+
+if ( !trait_exists(VcsCheckerMethods::class, false) ) :
+
+	trait VcsCheckerMethods {
+		/**
+		 * @var string The branch where to look for updates. Defaults to "master".
+		 */
+		protected $branch = 'master';
+
+		/**
+		 * @var Api Repository API client.
+		 */
+		protected $api = null;
+
+		public function setBranch($branch) {
+			$this->branch = $branch;
+			return $this;
+		}
+
+		/**
+		 * Set authentication credentials.
+		 *
+		 * @param array|string $credentials
+		 * @return $this
+		 */
+		public function setAuthentication($credentials) {
+			$this->api->setAuthentication($credentials);
+			return $this;
+		}
+
+		/**
+		 * @return Api
+		 */
+		public function getVcsApi() {
+			return $this->api;
+		}
+
+		public function getUpdate() {
+			$update = parent::getUpdate();
+
+			if ( isset($update) && !empty($update->download_url) ) {
+				$update->download_url = $this->api->signDownloadUrl($update->download_url);
+			}
+
+			return $update;
+		}
+
+		public function onDisplayConfiguration($panel) {
+			parent::onDisplayConfiguration($panel);
+			$panel->row('Branch', $this->branch);
+			$panel->row('Authentication enabled', $this->api->isAuthenticationEnabled() ? 'Yes' : 'No');
+			$panel->row('API client', get_class($this->api));
+		}
+	}
+
+endif;

lib/plugin-update-checker/README.md

@@ -0,0 +1,372 @@
+Plugin Update Checker
+=====================
+
+This is a custom update checker library for WordPress plugins and themes. It lets you add automatic update notifications and one-click upgrades to your commercial plugins, private themes, and so on. All you need to do is put your plugin/theme details in a JSON file, place the file on your server, and pass the URL to the library. The library periodically checks the URL to see if there's a new version available and displays an update notification to the user if necessary.
+
+From the users' perspective, it works just like with plugins and themes hosted on WordPress.org. The update checker uses the default upgrade UI that is familiar to most WordPress users.
+
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+**Table of Contents**
+
+- [Getting Started](#getting-started)
+  - [Self-hosted Plugins and Themes](#self-hosted-plugins-and-themes)
+    - [How to Release an Update](#how-to-release-an-update)
+    - [Notes](#notes)
+  - [GitHub Integration](#github-integration)
+    - [How to Release an Update](#how-to-release-an-update-1)
+    - [Notes](#notes-1)
+  - [BitBucket Integration](#bitbucket-integration)
+    - [How to Release an Update](#how-to-release-an-update-2)
+  - [GitLab Integration](#gitlab-integration)
+    - [How to Release a GitLab Update](#how-to-release-a-gitlab-update)
+- [Migrating from 4.x](#migrating-from-4x)
+- [License Management](#license-management)
+- [Resources](#resources)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+
+Getting Started
+---------------
+
+*Note:* In each of the below examples, part of the instructions are to create an instance of the update checker class. It's recommended to do this either during the `plugins_loaded` action or outside of any hooks. If you do it only during an `admin_*` action, then updates will not be visible to a wide variety of WordPress maanagement tools; they will only be visible to logged-in users on dashboard pages.
+
+### Self-hosted Plugins and Themes
+
+1. Download [the latest release](https://github.com/YahnisElsts/plugin-update-checker/releases/latest) and copy the `plugin-update-checker` directory to your plugin or theme.
+2. Go to the `examples` subdirectory and open the .json file that fits your project type. Replace the placeholder data with your plugin/theme details. 
+	- Plugin example:
+	
+		```json
+		{
+			"name" : "Plugin Name",
+			"version" : "2.0",
+			"download_url" : "https://example.com/plugin-name-2.0.zip",
+			"sections" : {
+				"description" : "Plugin description here. You can use HTML."
+			}
+		}
+		```
+		
+        This is a minimal example that leaves out optional fields. See [this table](https://docs.google.com/spreadsheets/d/1eOBbW7Go2qEQXReOOCdidMTf_tDYRq4JfegcO1CBPIs/edit?usp=sharing) for a full list of supported fields and their descriptions.
+	- Theme example:
+	
+		```json
+		{
+			"version": "2.0",
+			"details_url": "https://example.com/version-2.0-details.html",
+			"download_url": "https://example.com/example-theme-2.0.zip"
+		}
+		```
+		
+		This is actually a complete example that shows all theme-related fields. `version` and `download_url` should be self-explanatory. The `details_url` key specifies the page that the user will see if they click the "View version 1.2.3 details" link in an update notification.  
+3. Upload the JSON file to a publicly accessible location.
+4. Add the following code to the main plugin file or to the `functions.php` file:
+
+	```php
+	require 'path/to/plugin-update-checker/plugin-update-checker.php';
+	use YahnisElsts\PluginUpdateChecker\v5\PucFactory;
+ 
+	$myUpdateChecker = PucFactory::buildUpdateChecker(
+		'https://example.com/path/to/details.json',
+		__FILE__, //Full path to the main plugin file or functions.php.
+		'unique-plugin-or-theme-slug'
+	);
+	```
+	Note: If you're using the Composer autoloader, you don't need to explicitly `require` the library.
+
+#### How to Release an Update
+
+Change the `version` number in the JSON file and make sure that `download_url` points to the latest version. Update the other fields if necessary. Tip: You can use [wp-update-server](https://github.com/YahnisElsts/wp-update-server) to automate this process.
+
+By default, the library will check the specified URL for changes every 12 hours. You can force it to check immediately by clicking the "Check for updates" link on the "Plugins" page (it's next to the "Visit plugin site" link). Themes don't have that link, but you can also trigger an update check like this:
+ 
+ 1. Install [Debug Bar](https://srd.wordpress.org/plugins/debug-bar/).
+ 2. Click the "Debug" menu in the Admin Bar (a.k.a Toolbar).
+ 3. Open the "PUC (your-slug)" panel. 
+ 4. Click the "Check Now" button.  
+
+#### Notes
+- The second argument passed to `buildUpdateChecker` must be the absolute path to the main plugin file or any file in the theme directory. If you followed the "getting started" instructions, you can just use the `__FILE__` constant.
+- The third argument - i.e. the slug - is optional but recommended. In most cases, the slug should be the same as the name of your plugin directory. For example, if your plugin lives in `/wp-content/plugins/my-plugin`, set the slug to `my-plugin`. If the slug is omitted, the update checker will use the name of the main plugin file as the slug (e.g. `my-cool-plugin.php` &rarr; `my-cool-plugin`). This can lead to conflicts if your plugin has a generic file name like `plugin.php`. 
+	
+	This doesn't affect themes because PUC uses the theme directory name as the default slug. Still, if you're planning to use the slug in your own code - e.g. to filter updates or override update checker behaviour - it can be a good idea to set it explicitly. 
+
+### GitHub Integration
+
+1. Download [the latest release](https://github.com/YahnisElsts/plugin-update-checker/releases/latest) and copy the `plugin-update-checker` directory to your plugin or theme.
+2. Add the following code to the main plugin file or `functions.php`:
+
+	```php
+	require 'plugin-update-checker/plugin-update-checker.php';
+	use YahnisElsts\PluginUpdateChecker\v5\PucFactory;
+ 
+	$myUpdateChecker = PucFactory::buildUpdateChecker(
+		'https://github.com/user-name/repo-name/',
+		__FILE__,
+		'unique-plugin-or-theme-slug'
+	);
+	
+	//Set the branch that contains the stable release.
+	$myUpdateChecker->setBranch('stable-branch-name');
+
+	//Optional: If you're using a private repository, specify the access token like this:
+	$myUpdateChecker->setAuthentication('your-token-here');
+	```
+3. Plugins only: Add a `readme.txt` file formatted according to the [WordPress.org plugin readme standard](https://wordpress.org/plugins/readme.txt) to your repository. The contents of this file will be shown when the user clicks the "View version 1.2.3 details" link.
+
+#### How to Release an Update
+
+This library supports a couple of different ways to release updates on GitHub. Pick the one that best fits your workflow.
+
+- **GitHub releases** 
+	
+	Create a new release using the "Releases" feature on GitHub. The tag name and release title don't matter. The description is optional, but if you do provide one, it will be displayed when the user clicks the "View version x.y.z details" link on the "Plugins" page. Note that PUC ignores releases marked as "This is a pre-release".
+	
+	If you want to use release assets, call the `enableReleaseAssets()` method after creating the update checker instance:
+	```php
+	$myUpdateChecker->getVcsApi()->enableReleaseAssets();
+	```
+	
+- **Tags** 
+	
+	To release version 1.2.3, create a new Git tag named `v1.2.3` or `1.2.3`. That's it.
+	
+	PUC doesn't require strict adherence to [SemVer](https://semver.org/). These are all valid tag names: `v1.2.3`, `v1.2-foo`, `1.2.3_rc1-ABC`, `1.2.3.4.5`. However, be warned that it's not smart enough to filter out alpha/beta/RC versions. If that's a problem, you might want to use GitHub releases or branches instead.
+	
+- **Stable branch** 
+	
+	Point the update checker at a stable, production-ready branch: 
+	 ```php
+	 $updateChecker->setBranch('branch-name');
+	 ```
+	 PUC will periodically check the `Version` header in the main plugin file or `style.css` and display a notification if it's greater than the installed version.
+	 
+	 Caveat: If you set the branch to `master` (the default), the update checker will look for recent releases and tags first. It'll only use the `master` branch if it doesn't find anything else suitable.
+
+#### Notes
+
+The library will pull update details from the following parts of a release/tag/branch:
+
+- Version number
+	- The "Version" plugin header.
+	- The latest GitHub release or tag name.
+- Changelog
+	- The "Changelog" section of `readme.txt`.
+	- One of the following files:
+		CHANGES.md, CHANGELOG.md, changes.md, changelog.md
+	- GitHub release notes.
+- Required and tested WordPress versions
+	- The "Requires at least" and "Tested up to" fields in `readme.txt`.
+	- The following plugin headers:
+		`Required WP`, `Tested WP`, `Requires at least`, `Tested up to`
+- "Last updated" timestamp
+	- The creation timestamp of the latest GitHub release.
+	- The latest commit in the selected tag or branch.
+- Number of downloads
+	- The `download_count` statistic of the latest release.
+	- If you're not using GitHub releases, there will be no download stats.
+- Other plugin details - author, homepage URL, description
+	- The "Description" section of `readme.txt`.
+	- Remote plugin headers (i.e. the latest version on GitHub).
+	- Local plugin headers (i.e. the currently installed version).
+- Ratings, banners, screenshots
+	- Not supported.
+	
+### BitBucket Integration
+
+1. Download [the latest release](https://github.com/YahnisElsts/plugin-update-checker/releases/latest) and copy the `plugin-update-checker` directory to your plugin or theme.
+2. Add the following code to the main plugin file or `functions.php`:
+
+	```php
+	require 'plugin-update-checker/plugin-update-checker.php';
+	use YahnisElsts\PluginUpdateChecker\v5\PucFactory;
+ 
+	$myUpdateChecker = PucFactory::buildUpdateChecker(
+		'https://bitbucket.org/user-name/repo-name',
+		__FILE__,
+		'unique-plugin-or-theme-slug'
+	);
+
+	//Optional: If you're using a private repository, create an OAuth consumer
+	//and set the authentication credentials like this:
+	//Note: For now you need to check "This is a private consumer" when
+	//creating the consumer to work around #134:
+	// https://github.com/YahnisElsts/plugin-update-checker/issues/134
+	$myUpdateChecker->setAuthentication(array(
+		'consumer_key' => '...',
+		'consumer_secret' => '...',
+	));
+
+	//Optional: Set the branch that contains the stable release.
+	$myUpdateChecker->setBranch('stable-branch-name');
+	```
+3. Optional: Add a `readme.txt` file formatted according to the [WordPress.org plugin readme standard](https://wordpress.org/plugins/readme.txt) to your repository. For plugins, the contents of this file will be shown when the user clicks the "View version 1.2.3 details" link.
+
+#### How to Release an Update
+
+BitBucket doesn't have an equivalent to GitHub's releases, so the process is slightly different. You can use any of the following approaches: 
+
+- **`Stable tag` header** 
+	
+	This is the recommended approach if you're using tags to mark each version. Add a `readme.txt` file formatted according to the [WordPress.org plugin readme standard](https://wordpress.org/plugins/readme.txt) to your repository. Set the "stable tag" header to the tag that represents the latest release. Example:
+	```text
+	Stable tag: v1.2.3
+	```
+	The tag doesn't have to start with a "v" or follow any particular format. You can use any name you like as long as it's a valid Git tag.
+	
+	Tip: If you explicitly set a stable branch, the update checker will look for a `readme.txt` in that branch. Otherwise it will only look at the `master` branch.
+	
+- **Tags** 
+	
+	You can skip the "stable tag" bit and just create a new Git tag named `v1.2.3` or `1.2.3`. The update checker will look at the most recent tags and pick the one that looks like the highest version number.
+	
+	PUC doesn't require strict adherence to [SemVer](https://semver.org/). These are all valid tag names: `v1.2.3`, `v1.2-foo`, `1.2.3_rc1-ABC`, `1.2.3.4.5`. However, be warned that it's not smart enough to filter out alpha/beta/RC versions.
+	
+- **Stable branch** 
+	
+	Point the update checker at a stable, production-ready branch: 
+	 ```php
+	 $updateChecker->setBranch('branch-name');
+	 ```
+	 PUC will periodically check the `Version` header in the main plugin file or `style.css` and display a notification if it's greater than the installed version. Caveat: If you set the branch to `master`, the update checker will still look for tags first.
+
+### GitLab Integration
+
+1. Download [the latest release](https://github.com/YahnisElsts/plugin-update-checker/releases/latest) and copy the `plugin-update-checker` directory to your plugin or theme.
+2. Add the following code to the main plugin file or `functions.php` and define how you want to check for updates from Gitlab (refer to: [Gitlab: How to Release an Update](#how-to-release-a-gitlab-update)):
+
+	```php
+	require 'plugin-update-checker/plugin-update-checker.php';
+	use YahnisElsts\PluginUpdateChecker\v5\PucFactory;
+
+	$myUpdateChecker = PucFactory::buildUpdateChecker(
+		'https://gitlab.com/user-name/repo-name/',
+		__FILE__,
+		'unique-plugin-or-theme-slug'
+	);
+
+	//Optional: If you're using a private repository, specify the access token like this:
+	$myUpdateChecker->setAuthentication('your-token-here');
+	```
+
+	Alternatively, if you're using a self-hosted GitLab instance, initialize the update checker like this:
+	```php
+	use YahnisElsts\PluginUpdateChecker\v5p3\Vcs\PluginUpdateChecker;
+	use YahnisElsts\PluginUpdateChecker\v5p3\Vcs\GitLabApi;
+	
+	$myUpdateChecker = new PluginUpdateChecker(
+		new GitLabApi('https://myserver.com/user-name/repo-name/'),
+		__FILE__,
+		'unique-plugin-or-theme-slug'
+	);
+	//Optional: Add setAuthentication(...) and setBranch(...) as shown above.  
+	```
+	If you're using a self-hosted GitLab instance and [subgroups or nested groups](https://docs.gitlab.com/ce/user/group/subgroups/index.html), you have to tell the update checker which parts of the URL are subgroups:
+	```php
+	use YahnisElsts\PluginUpdateChecker\v5p3\Vcs\PluginUpdateChecker;
+	use YahnisElsts\PluginUpdateChecker\v5p3\Vcs\GitLabApi;
+   
+	$myUpdateChecker = new PluginUpdateChecker(
+		new GitLabApi(
+			'https://myserver.com/group-name/subgroup-level1/subgroup-level2/subgroup-level3/repo-name/', 
+			null, 
+			'subgroup-level1/subgroup-level2/subgroup-level3'
+		),
+		__FILE__,
+		'unique-plugin-or-theme-slug'
+	);
+	```
+
+3. Plugins only: Add a `readme.txt` file formatted according to the [WordPress.org plugin readme standard](https://wordpress.org/plugins/readme.txt) to your repository. The contents of this file will be shown when the user clicks the "View version 1.2.3 details" link.
+
+#### How to Release a GitLab Update
+
+A GitLab repository can be checked for updates in 3 different ways.
+
+- **GitLab releases**
+	
+	Create a new release using the "Releases" feature on GitLab. The tag name should match the version number. You can add a `v` prefix to the tag, like `v1.2.3`. Releases that are marked as ["Upcoming Release"](https://docs.gitlab.com/ee/user/project/releases/index.html#upcoming-releases) will be automatically ignored.
+	
+	If you want to use custom release assets, call the `enableReleaseAssets()` method after creating the update checker instance:
+	```php
+	$myUpdateChecker->getVcsApi()->enableReleaseAssets();
+	```
+	
+	By default, PUC will use the first available asset link, regardless of type. You can pass a regular expression to `enableReleaseAssets()` to make it pick the first link where the URL matches the regex. For example:
+	```php
+	$myUpdateChecker->getVcsApi()->enableReleaseAssets('/\.zip($|[?&#])/i');
+	```
+	
+	**Tip:** You can use a Gitlab CI/CD Pipeline to automatically generate your update on release using a Generic Package. For more information about generic packages, refer to the following links:
+		- [Gitlab CI/CD Release Documentation](https://docs.gitlab.com/ee/user/project/releases/#create-release-from-gitlab-ci)
+		- [Gitlab Release Assets as Generic Package Documentation](https://gitlab.com/gitlab-org/release-cli/-/tree/master/docs/examples/release-assets-as-generic-package/)
+		- [Example .gitlab-ci.yml file using Release Generic Packages for generating a update package from the Sensei-LMS wordpress plugin](https://gist.github.com/timwiel/9dfd3526c768efad4973254085e065ce)
+
+- **Tags**
+
+	To release version 1.2.3, create a new Git tag named `v1.2.3` or `1.2.3`. The update checker will look at recent tags and use the one that looks like the highest version number.
+	
+	PUC doesn't require strict adherence to [SemVer](https://semver.org/). However, be warned that it's not smart enough to filter out alpha/beta/RC versions. If that's a problem, you might want to use GitLab branches instead.
+
+- **Stable branch**
+
+	Point the update checker at any stable, production-ready branch:
+	```php
+	$myUpdateChecker->setBranch('stable-branch-name');
+	```
+	PUC will periodically check the `Version` header in the main plugin file or `style.css` and display a notification if it's greater than the installed version. Caveat: Even if you set the branch to `main` (the default) or `master` (the historical default), the update checker will still look for recent releases and tags first.
+
+Migrating from 4.x
+------------------
+
+Older versions of the library didn't use namespaces. Code that was written for those versions will need to be updated to work with the current version. At a minimum, you'll need to change the factory class name. 
+
+Old code:
+```php
+$myUpdateChecker = Puc_v4_Factory::buildUpdateChecker(
+	'https://example.com/info.json',
+	__FILE__,
+	'my-slug'
+);
+```
+
+New code:
+```php
+use YahnisElsts\PluginUpdateChecker\v5\PucFactory;
+
+$myUpdateChecker = PucFactory::buildUpdateChecker(
+	'https://example.com/info.json',
+	__FILE__,
+	'my-slug'
+);
+```
+
+Other classes have also been renamed, usually by simply removing the `Puc_vXpY_` prefix and converting `Category_Thing` to `Category\Thing`. Here's a table of the most commonly used classes and their new names:
+
+| Old class name                      | New class name                                                 |
+|-------------------------------------|----------------------------------------------------------------|
+| `Puc_v4_Factory`                    | `YahnisElsts\PluginUpdateChecker\v5\PucFactory`                |
+| `Puc_v4p13_Factory`                 | `YahnisElsts\PluginUpdateChecker\v5p3\PucFactory`              |
+| `Puc_v4p13_Plugin_UpdateChecker`    | `YahnisElsts\PluginUpdateChecker\v5p3\Plugin\UpdateChecker`    |
+| `Puc_v4p13_Theme_UpdateChecker`     | `YahnisElsts\PluginUpdateChecker\v5p3\Theme\UpdateChecker`     |
+| `Puc_v4p13_Vcs_PluginUpdateChecker` | `YahnisElsts\PluginUpdateChecker\v5p3\Vcs\PluginUpdateChecker` |
+| `Puc_v4p13_Vcs_ThemeUpdateChecker`  | `YahnisElsts\PluginUpdateChecker\v5p3\Vcs\ThemeUpdateChecker`  |
+| `Puc_v4p13_Vcs_GitHubApi`           | `YahnisElsts\PluginUpdateChecker\v5p3\Vcs\GitHubApi`           |
+| `Puc_v4p13_Vcs_GitLabApi`           | `YahnisElsts\PluginUpdateChecker\v5p3\Vcs\GitLabApi`           |
+| `Puc_v4p13_Vcs_BitBucketApi`        | `YahnisElsts\PluginUpdateChecker\v5p3\Vcs\BitBucketApi`        |
+
+License Management
+------------------
+
+Currently, the update checker doesn't have any built-in license management features. It only provides some hooks that you can use to, for example, append license keys to update requests (`$updateChecker->addQueryArgFilter()`). If you're looking for ways to manage and verify licenses, please post your feedback in [this issue](https://github.com/YahnisElsts/plugin-update-checker/issues/222).
+
+Resources
+---------
+
+- [This blog post](https://w-shadow.com/blog/2010/09/02/automatic-updates-for-any-plugin/) has more information about the update checker API. *Slightly out of date.*
+- [Debug Bar](https://wordpress.org/plugins/debug-bar/) - useful for testing and debugging the update checker.
+- [Update format reference](https://docs.google.com/spreadsheets/d/1eOBbW7Go2qEQXReOOCdidMTf_tDYRq4JfegcO1CBPIs/edit?usp=sharing) - describes all fields supported by the JSON-based update information format used by the update checker. Only covers plugins. Themes use a similar but more limited format.
+- [Securing download links](https://w-shadow.com/blog/2013/03/19/plugin-updates-securing-download-links/) - a general overview.
+- [A GUI for entering download credentials](https://open-tools.net/documentation/tutorial-automatic-updates.html#wordpress)
+- [Theme Update Checker](https://w-shadow.com/blog/2011/06/02/automatic-updates-for-commercial-themes/) - an older, theme-only variant of this update checker.

lib/plugin-update-checker/composer.json

@@ -0,0 +1,23 @@
+{
+	"name": "yahnis-elsts/plugin-update-checker",
+	"type": "library",
+	"description": "A custom update checker for WordPress plugins and themes. Useful if you can't host your plugin in the official WP repository but still want it to support automatic updates.",
+	"keywords": ["wordpress", "plugin updates", "automatic updates", "theme updates"],
+	"homepage": "https://github.com/YahnisElsts/plugin-update-checker/",
+	"license": "MIT",
+	"authors": [
+		{
+			"name": "Yahnis Elsts",
+			"email": "whiteshadow@w-shadow.com",
+			"homepage": "https://w-shadow.com/",
+			"role": "Developer"
+		}
+	],
+	"require": {
+		"php": ">=5.6.20",
+		"ext-json": "*"
+	},
+	"autoload": {
+		"files": ["load-v5p3.php"]
+	}
+}

lib/plugin-update-checker/css/puc-debug-bar.css

@@ -0,0 +1,70 @@
+.puc-debug-bar-panel-v5 pre {
+	margin-top: 0;
+}
+
+/* Style the debug data table to match "widefat" table style used by WordPress. */
+table.puc-debug-data {
+    width: 100%;
+    clear: both;
+    margin: 0;
+
+    border-spacing: 0;
+    background-color: #f9f9f9;
+
+    border-radius: 3px;
+    border: 1px solid #dfdfdf;
+    border-collapse: separate;
+}
+
+table.puc-debug-data * {
+    word-wrap: break-word;
+}
+
+table.puc-debug-data th {
+	width: 11em;
+    padding: 7px 7px 8px;
+    text-align: left;
+
+    font-family: "Georgia", "Times New Roman", "Bitstream Charter", "Times", serif;
+    font-weight: 400;
+    font-size: 14px;
+    line-height: 1.3em;
+    text-shadow: rgba(255, 255, 255, 0.804) 0 1px 0;
+}
+
+table.puc-debug-data td, table.puc-debug-data th {
+    border-width: 1px 0;
+    border-style: solid;
+
+    border-top-color: #fff;
+    border-bottom-color: #dfdfdf;
+
+    text-transform: none;
+}
+
+table.puc-debug-data td {
+    color: #555;
+    font-size: 12px;
+    padding: 4px 7px 2px;
+    vertical-align: top;
+}
+
+.puc-ajax-response {
+	border: 1px solid #dfdfdf;
+	border-radius: 3px;
+	padding: 0.5em;
+	margin: 5px 0;
+	background-color: white;
+}
+
+.puc-ajax-nonce {
+	display: none;
+}
+
+.puc-ajax-response dt {
+	margin: 0;
+}
+
+.puc-ajax-response dd {
+	margin: 0 0 1em;
+}

lib/plugin-update-checker/examples/plugin.json

@@ -0,0 +1,52 @@
+{
+	"name": "My Example Plugin",
+	"version": "2.0",
+	"download_url": "http://example.com/updates/example-plugin.zip",
+
+	"homepage": "http://example.com/",
+	"requires": "4.5",
+	"tested": "4.8",
+	"last_updated": "2017-01-01 16:17:00",
+	"upgrade_notice": "Here's why you should upgrade...",
+
+	"author": "Janis Elsts",
+	"author_homepage": "http://example.com/",
+
+	"sections": {
+		"description": "(Required) Plugin description. Basic HTML can be used in all sections.",
+		"installation": "(Recommended) Installation instructions.",
+		"changelog": "(Recommended) Changelog. <p>This section will be displayed by default when the user clicks 'View version x.y.z details'.</p>",
+		"custom_section": "This is a custom section labeled 'Custom Section'."
+	},
+	
+	"icons" : {
+		"1x" : "http://w-shadow.com/files/external-update-example/assets/icon-128x128.png",
+		"2x" : "http://w-shadow.com/files/external-update-example/assets/icon-256x256.png"
+    },
+
+	"banners": {
+		"low": "http://w-shadow.com/files/external-update-example/assets/banner-772x250.png",
+		"high": "http://w-shadow.com/files/external-update-example/assets/banner-1544x500.png"
+	},
+
+	"translations": [
+		{
+			"language": "fr_FR",
+			"version": "4.0",
+			"updated": "2016-04-22 23:22:42",
+			"package": "http://example.com/updates/translations/french-language-pack.zip"
+		},
+		{
+			"language": "de_DE",
+			"version": "5.0",
+			"updated": "2016-04-22 23:22:42",
+			"package": "http://example.com/updates/translations/german-language-pack.zip"
+		}
+	],
+
+	"rating": 90,
+	"num_ratings": 123,
+
+	"downloaded": 1234,
+	"active_installs": 12345
+}

lib/plugin-update-checker/examples/theme.json

@@ -0,0 +1,5 @@
+{
+	"version": "2.0",
+	"details_url": "http://example.com/version-2.0-details.html",
+	"download_url": "http://example.com/example-theme-2.0.zip"
+}

lib/plugin-update-checker/js/debug-bar.js

@@ -0,0 +1,54 @@
+jQuery(function($) {
+
+	function runAjaxAction(button, action) {
+		button = $(button);
+		var panel = button.closest('.puc-debug-bar-panel-v5');
+		var responseBox = button.closest('td').find('.puc-ajax-response');
+
+		responseBox.text('Processing...').show();
+		$.post(
+			ajaxurl,
+			{
+				action  : action,
+				uid     : panel.data('uid'),
+				_wpnonce: panel.data('nonce')
+			},
+			function(data) {
+				//The response contains HTML that should already be escaped in server-side code.
+				//phpcs:ignore WordPressVIPMinimum.JS.HTMLExecutingFunctions.html
+				responseBox.html(data);
+			},
+			'html'
+		);
+	}
+
+	$('.puc-debug-bar-panel-v5 input[name="puc-check-now-button"]').on('click', function() {
+		runAjaxAction(this, 'puc_v5_debug_check_now');
+		return false;
+	});
+
+	$('.puc-debug-bar-panel-v5 input[name="puc-request-info-button"]').on('click', function() {
+		runAjaxAction(this, 'puc_v5_debug_request_info');
+		return false;
+	});
+
+
+	// Debug Bar uses the panel class name as part of its link and container IDs. This means we can
+	// end up with multiple identical IDs if more than one plugin uses the update checker library.
+	// Fix it by replacing the class name with the plugin slug.
+	var panels = $('#debug-menu-targets').find('.puc-debug-bar-panel-v5');
+	panels.each(function() {
+		var panel = $(this);
+		var uid = panel.data('uid');
+		var target = panel.closest('.debug-menu-target');
+
+		//Change the panel wrapper ID.
+		target.attr('id', 'debug-menu-target-puc-' + uid);
+
+		//Change the menu link ID as well and point it at the new target ID.
+		$('#debug-bar-menu').find('.puc-debug-menu-link-' + uid)
+			.closest('.debug-menu-link')
+			.attr('id', 'debug-menu-link-puc-' + uid)
+			.attr('href', '#' + target.attr('id'));
+	});
+});

lib/plugin-update-checker/languages/plugin-update-checker-ca.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2019-09-25 18:15+0200\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: ca\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprova si hi ha actualitzacions"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "L’extensió %s està actualitzada."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nova versió de l’extensió %s està disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No s’ha pogut determinar si hi ha actualitzacions per a %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estat del comprovador d’actualitzacions desconegut \"%s\""
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hi ha cap registre de canvis disponible."

lib/plugin-update-checker/languages/plugin-update-checker-cs_CZ.po

@@ -0,0 +1,45 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2017-05-20 10:53+0300\n"
+"PO-Revision-Date: 2017-07-05 15:39+0000\n"
+"Last-Translator: Vojtěch Sajdl <vojtech@sajdl.com>\n"
+"Language-Team: Czech (Czech Republic)\n"
+"Language: cs-CZ\n"
+"Plural-Forms: nplurals=2; plural=(n != 1)\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Loco-Source-Locale: cs_CZ\n"
+"X-Generator: Loco - https://localise.biz/\n"
+"X-Poedit-Basepath: ..\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"X-Poedit-SearchPath-0: .\n"
+"X-Loco-Parser: loco_parse_po"
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:358
+msgid "Check for updates"
+msgstr "Zkontrolovat aktualizace"
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:405
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "Plugin %s je aktuální."
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:407
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Nová verze pluginu %s je dostupná."
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:409
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Neznámý status kontroly aktualizací \"%s\""
+
+#: Puc/v4p1/Vcs/PluginUpdateChecker.php:83
+msgid "There is no changelog available."
+msgstr "Changelog není dostupný."

lib/plugin-update-checker/languages/plugin-update-checker-da_DK.po

@@ -0,0 +1,42 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-05-20 10:53+0300\n"
+"PO-Revision-Date: 2017-10-17 11:07+0200\n"
+"Last-Translator: Mikk3lRo\n"
+"Language-Team: Mikk3lRo\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.0.4\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Language: da_DK\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:358
+msgid "Check for updates"
+msgstr "Undersøg for opdateringer"
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:405
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "Plugin'et %s er allerede opdateret."
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:407
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "En ny version af plugin'et %s er tilgængelig."
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:409
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Ukendt opdateringsstatus: \"%s\""
+
+#: Puc/v4p1/Vcs/PluginUpdateChecker.php:83
+msgid "There is no changelog available."
+msgstr "Der er ingen ændringslog tilgængelig."

lib/plugin-update-checker/languages/plugin-update-checker-de_DE.po

@@ -0,0 +1,38 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2016-06-29 20:21+0100\n"
+"PO-Revision-Date: 2016-06-29 20:23+0100\n"
+"Last-Translator: Igor Lückel <info@igorlueckel.de>\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 1.8.1\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e\n"
+"Language: de_DE\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: github-checker.php:137
+msgid "There is no changelog available."
+msgstr "Es ist keine Liste von Programmänderungen verfügbar."
+
+#: plugin-update-checker.php:852
+msgid "Check for updates"
+msgstr "Nach Update suchen"
+
+#: plugin-update-checker.php:896
+msgid "This plugin is up to date."
+msgstr "Das Plugin ist aktuell."
+
+#: plugin-update-checker.php:898
+msgid "A new version of this plugin is available."
+msgstr "Es ist eine neue Version für das Plugin verfügbar."
+
+#: plugin-update-checker.php:900
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Unbekannter Update Status \"%s\""

lib/plugin-update-checker/languages/plugin-update-checker-es_AR.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:13-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_CL.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:14-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_CO.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:14-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_CR.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:14-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_DO.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:14-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_ES.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 14:56-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_GT.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:14-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_HN.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:14-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_MX.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 14:57-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_PE.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:15-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_PR.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:15-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_UY.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 15:15-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-es_VE.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2020-03-21 14:57-0400\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.3\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: \n"
+"Language: es_ES\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Comprobar si hay actualizaciones"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "El plugin %s está actualizado."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nueva versión del %s plugin está disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "No se pudo determinar si hay actualizaciones disponibles para %s."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Estado del comprobador de actualización desconocido «%s»"
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "No hay un registro de cambios disponible."

lib/plugin-update-checker/languages/plugin-update-checker-fa_IR.po

@@ -0,0 +1,38 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2016-02-17 14:21+0100\n"
+"PO-Revision-Date: 2016-10-28 14:30+0330\n"
+"Last-Translator: studio RVOLA <hello@rvola.com>\n"
+"Language-Team: Pro Style <info@prostyle.ir>\n"
+"Language: fa_IR\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 1.8.8\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n > 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: github-checker.php:120
+msgid "There is no changelog available."
+msgstr "شرحی برای تغییرات  یافت نشد"
+
+#: plugin-update-checker.php:637
+msgid "Check for updates"
+msgstr "بررسی برای بروزرسانی "
+
+#: plugin-update-checker.php:681
+msgid "This plugin is up to date."
+msgstr "شما از آخرین نسخه استفاده میکنید . به‌روز باشید"
+
+#: plugin-update-checker.php:683
+msgid "A new version of this plugin is available."
+msgstr "نسخه جدیدی برای افزونه ارائه شده است ."
+
+#: plugin-update-checker.php:685
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "وضعیت ناشناخته برای بروزرسانی \"%s\""

lib/plugin-update-checker/languages/plugin-update-checker-fr_CA.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-11-24 17:02+0200\n"
+"PO-Revision-Date: 2018-02-12 10:32-0500\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.0.4\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n > 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: Eric Gagnon <eric.gagnon@banq.qc.ca>\n"
+"Language: fr_CA\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:395
+msgid "Check for updates"
+msgstr "Vérifier les mises à jour"
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:548
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "L’extension %s est à jour."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:550
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Une nouvelle version de l’extension %s est disponible."
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:552
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "Impossible de déterminer si une mise à jour est disponible pour \"%s\""
+
+#: Puc/v4p3/Plugin/UpdateChecker.php:558
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Un problème inconnu est survenu \"%s\""
+
+#: Puc/v4p3/Vcs/PluginUpdateChecker.php:95
+msgid "There is no changelog available."
+msgstr "Il n’y a aucun journal de mise à jour disponible."

lib/plugin-update-checker/languages/plugin-update-checker-fr_FR.po

@@ -0,0 +1,42 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2017-07-07 14:53+0200\n"
+"PO-Revision-Date: 2017-07-07 14:54+0200\n"
+"Language-Team: studio RVOLA <http://www.rvola.com>\n"
+"Language: fr_FR\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.0.2\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n > 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: Nicolas GEHIN\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:358
+msgid "Check for updates"
+msgstr "Vérifier les mises à jour"
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:405
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "L’extension %s est à jour."
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:407
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Une nouvelle version de l’extension %s est disponible."
+
+#: Puc/v4p1/Plugin/UpdateChecker.php:409
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Un problème inconnu est survenu \"%s\""
+
+#: Puc/v4p1/Vcs/PluginUpdateChecker.php:85
+msgid "There is no changelog available."
+msgstr "Il n’y a aucun journal de mise à jour disponible."

lib/plugin-update-checker/languages/plugin-update-checker-hu_HU.po

@@ -0,0 +1,41 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2016-01-11 21:23+0100\n"
+"PO-Revision-Date: 2016-01-11 21:25+0100\n"
+"Last-Translator: Tamás András Horváth <htomy92@gmail.com>\n"
+"Language-Team: \n"
+"Language: hu_HU\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 1.8.6\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: github-checker.php:137
+msgid "There is no changelog available."
+msgstr "Nem érhető el a changelog."
+
+#: plugin-update-checker.php:852
+msgid "Check for updates"
+msgstr "Frissítés ellenőrzése"
+
+#: plugin-update-checker.php:896
+msgid "This plugin is up to date."
+msgstr "Ez a plugin naprakész."
+
+#: plugin-update-checker.php:898
+msgid "A new version of this plugin is available."
+msgstr "Új verzió érhető el a kiegészítőhöz"
+
+#: plugin-update-checker.php:900
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Ismeretlen a frissítés ellenőrző státusza \"%s\""
+
+#~ msgid "Every %d hours"
+#~ msgstr "Minden %d órában"

lib/plugin-update-checker/languages/plugin-update-checker-it_IT.po

@@ -0,0 +1,48 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: plugin-update-checker\n"
+"POT-Creation-Date: 2020-08-08 14:36+0300\n"
+"PO-Revision-Date: 2022-05-20 00:17+0200\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 3.0\n"
+"X-Poedit-Basepath: ..\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+"X-Poedit-KeywordsList: __;_e;_x:1,2c;_x\n"
+"Last-Translator: d79\n"
+"Language: it_IT\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: Puc/v4p11/Plugin/Ui.php:128
+msgid "Check for updates"
+msgstr "Verifica aggiornamenti"
+
+#: Puc/v4p11/Plugin/Ui.php:213
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "Il plugin %s è aggiornato."
+
+#: Puc/v4p11/Plugin/Ui.php:215
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "Una nuova versione del plugin %s è disponibile."
+
+#: Puc/v4p11/Plugin/Ui.php:217
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "Non è possibile verificare se c'è un aggiornamento disponibile per %s."
+
+#: Puc/v4p11/Plugin/Ui.php:223
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "Stato di controllo aggiornamenti sconosciuto \"%s\""
+
+#: Puc/v4p11/Vcs/PluginUpdateChecker.php:98
+msgid "There is no changelog available."
+msgstr "Non c'è alcun registro delle modifiche disponibile."

lib/plugin-update-checker/languages/plugin-update-checker-ja.po

@@ -0,0 +1,57 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: \n"
+"POT-Creation-Date: 2019-07-15 17:07+0900\n"
+"PO-Revision-Date: 2019-07-15 17:12+0900\n"
+"Last-Translator: tak <tak7725@gmail.com>\n"
+"Language-Team: \n"
+"Language: ja_JP\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"X-Generator: Poedit 2.2.3\n"
+"X-Poedit-Basepath: ../../../../../../Applications/XAMPP/xamppfiles/htdocs/"
+"kisagai/wordpress/wp-content/plugins/simple-stripe-gateway/Puc\n"
+"Plural-Forms: nplurals=1; plural=0;\n"
+"X-Poedit-KeywordsList: __;_x:1,2c\n"
+"X-Poedit-SearchPath-0: .\n"
+
+#: v4p7/Plugin/Ui.php:54
+msgid "View details"
+msgstr "詳細を表示"
+
+#: v4p7/Plugin/Ui.php:77
+#, php-format
+msgid "More information about %s"
+msgstr "%sについての詳細"
+
+#: v4p7/Plugin/Ui.php:128
+msgid "Check for updates"
+msgstr "アップデートを確認"
+
+#: v4p7/Plugin/Ui.php:213
+#, php-format
+msgctxt "the plugin title"
+msgid "The %s plugin is up to date."
+msgstr "%s プラグインは、最新バージョンです。"
+
+#: v4p7/Plugin/Ui.php:215
+#, php-format
+msgctxt "the plugin title"
+msgid "A new version of the %s plugin is available."
+msgstr "%s プラグインの最新バージョンがあります。"
+
+#: v4p7/Plugin/Ui.php:217
+#, php-format
+msgctxt "the plugin title"
+msgid "Could not determine if updates are available for %s."
+msgstr "%s のアップデートがあるかどうかを判断できませんでした。"
+
+#: v4p7/Plugin/Ui.php:223
+#, php-format
+msgid "Unknown update checker status \"%s\""
+msgstr "バージョンアップの確認で想定外の状態になりました。ステータス：”%s”"
+
+#: v4p7/Vcs/PluginUpdateChecker.php:98
+msgid "There is no changelog available."
+msgstr "更新履歴はありません。"