resourceloader: Add $wgIncludejQueryMigrate option

Bug: T280944
Change-Id: I61aa56368bf8868f369dfc294b5d7b4435013670

RELEASE-NOTES-1.36

@@ -42,6 +42,8 @@ is no longer recommended and the option has been removed.
 * (T157145) $wgSkinMetaTags – This setting allows configuration of skins to
   support meta tags. These tags make sharing of MediaWiki pages on a variety of
   social platforms more contentful and thus useful.
+* (T280944) $wgIncludejQueryMigrate - This setting allows the jQuery Migrate
+  plugin to be disabled. It has been enabled by default since MediaWiki 1.27.
 * …
 
 ==== Changed configuration ====

includes/DefaultSettings.php

@@ -4411,6 +4411,17 @@ $wgResourceLoaderDebug = false;
  */
 $wgIncludeLegacyJavaScript = false;
 
+/**
+ * Whether to load the jquery.migrate library.
+ *
+ * This provides jQuery 1.12 features that were removed in jQuery 3.0.
+ * See also <https://jquery.com/upgrade-guide/3.0/> and
+ * <https://phabricator.wikimedia.org/T280944>.
+ *
+ * @deprecated since 1.36
+ */
+$wgIncludejQueryMigrate = true;
+
 /**
  * ResourceLoader will not generate URLs whose query string is more than
  * this many characters long, and will instead use multiple requests with

resources/Resources.php

@@ -116,10 +116,14 @@ return [
 	// These modules' dependencies MUST be dependency-free (having dependencies would cause recursion).
 
 	'jquery' => [
-		'scripts' => [
-			'resources/lib/jquery/jquery.js',
-			'resources/lib/jquery/jquery.migrate.js',
-		],
+		'scripts' => ( $GLOBALS['wgIncludejQueryMigrate'] ?
+			[
+				'resources/lib/jquery/jquery.js',
+				'resources/lib/jquery/jquery.migrate.js',
+			] : [
+				'resources/lib/jquery/jquery.js'
+			]
+		),
 		'targets' => [ 'desktop', 'mobile' ],
 	],
 	'es6-polyfills' => [