AutoLoader: Drop support for $wgAutoloadAttemptLowercase

This setting has been deprecated since 1.35.

Bug: T231412
Change-Id: I88cb45a2dcbb19c2976824279bf95a66ae9afd91

RELEASE-NOTES-1.40

@@ -51,6 +51,8 @@ For notes on 1.39.x and older releases, see HISTORY.
   set $wgShellboxUrls instead.
 * $wgParserTestFiles which was deprecated in 1.30 has now been removed;
   extensions can place their parser test files in `tests/parser` instead.
+* (T231412) $wgAutoloadAttemptLowercase, which was deprecated in 1.35,
+  no longer has any effect.
 * …
 
 === New user-facing features in 1.40 ===

docs/config-schema.yaml

@@ -6747,14 +6747,6 @@ config-schema:
             special pages to either a class name to be instantiated, or a callback to use for
             creating the special page object. In both cases, the result must be an instance of
             SpecialPage.
-    AutoloadAttemptLowercase:
-        default: false
-        deprecated: 'since 1.35'
-        description: |-
-            Switch controlling legacy case-insensitive classloading.
-            Do not disable if your wiki must support data created by PHP4, or by
-            MediaWiki 1.4 or earlier.
-            @deprecated since 1.35
     ExtensionCredits:
         default: {  }
         type: object

includes/AutoLoader.php

@@ -85,12 +85,6 @@ class AutoLoader {
 		'Wikimedia\\UUID\\' => __DIR__ . '/libs/uuid/',
 	];
 
-	/**
-	 * Cache for lower-case version of the content of $wgAutoloadLocalClasses.
-	 * @var array|null
-	 */
-	private static $autoloadLocalClassesLower = null;
-
 	/**
 	 * @var string[] Namespace (ends with \) => Path (ends with /)
 	 * @internal Will become private in 1.40.
@@ -166,7 +160,7 @@ class AutoLoader {
 	 * @return string|null The path containing the class, not null if not found
 	 */
 	public static function find( $className ): ?string {
-		global $wgAutoloadLocalClasses, $wgAutoloadClasses, $wgAutoloadAttemptLowercase;
+		global $wgAutoloadLocalClasses, $wgAutoloadClasses;
 
 		// NOTE: $wgAutoloadClasses is supported for compatibility with old-style extension
 		//       registration files.
@@ -176,25 +170,6 @@ class AutoLoader {
 			$wgAutoloadClasses[$className] ??
 			false;
 
-		if ( !$filename && $wgAutoloadAttemptLowercase ) {
-			// Try a different capitalisation.
-			//
-			// PHP 4 objects are always serialized with the classname coerced to lowercase,
-			// and we are plagued with several legacy uses created by MediaWiki < 1.5, see
-			// https://wikitech.wikimedia.org/wiki/Text_storage_data
-			if ( self::$autoloadLocalClassesLower === null ) {
-				self::$autoloadLocalClassesLower = array_change_key_case( $wgAutoloadLocalClasses, CASE_LOWER );
-			}
-			$lowerClass = strtolower( $className );
-			if ( isset( self::$autoloadLocalClassesLower[$lowerClass] ) ) {
-				if ( function_exists( 'wfDebugLog' ) ) {
-					wfDebugLog( 'autoloader', "Class {$className} was loaded using incorrect case" );
-				}
-				// @phan-suppress-next-line PhanTypeArraySuspiciousNullable
-				$filename = self::$autoloadLocalClassesLower[$lowerClass];
-			}
-		}
-
 		if ( !$filename && strpos( $className, '\\' ) !== false ) {
 			// This class is namespaced, so look in the namespace map
 			$prefix = $className;
@@ -246,14 +221,6 @@ class AutoLoader {
 		}
 	}
 
-	/**
-	 * Method to clear the protected class property $autoloadLocalClassesLower.
-	 * Used in tests.
-	 */
-	public static function resetAutoloadLocalClassesLower() {
-		self::$autoloadLocalClassesLower = null;
-	}
-
 	///// Methods used during testing //////////////////////////////////////////////
 	private static function assertTesting( $method ) {
 		if ( !defined( 'MW_PHPUNIT_TEST' ) ) {

includes/MainConfigNames.php

@@ -3859,13 +3859,6 @@ class MainConfigNames {
 	 */
 	public const SpecialPages = 'SpecialPages';
 
-	/**
-	 * Name constant for the AutoloadAttemptLowercase setting, for use with Config::get()
-	 * @see MainConfigSchema::AutoloadAttemptLowercase
-	 * @deprecated since 1.35
-	 */
-	public const AutoloadAttemptLowercase = 'AutoloadAttemptLowercase';
-
 	/**
 	 * Name constant for the ExtensionCredits setting, for use with Config::get()
 	 * @see MainConfigSchema::ExtensionCredits

includes/MainConfigSchema.php

@@ -10851,16 +10851,20 @@ class MainConfigSchema {
 	];
 
 	/**
-	 * Switch controlling legacy case-insensitive classloading.
+	 * Obsolete switch that controlled legacy case-insensitive classloading.
 	 *
-	 * Do not disable if your wiki must support data created by PHP4, or by
-	 * MediaWiki 1.4 or earlier.
+	 * Case-insensitive classloading was needed for loading data that had
+	 * been serialized by PHP 4 with the class names converted to lowercase.
+	 * It is no longer necessary since 1.31; the lowercase forms in question
+	 * are now listed in autoload.php (T166759).
 	 *
 	 * @deprecated since 1.35
 	 */
 	public const AutoloadAttemptLowercase = [
 		'default' => false,
-		'deprecated' => 'since 1.35',
+		'obsolete' => 'Since 1.40; no longer has any effect.',
+		'description' => 'Has been emitting warnings since 1.39 (LTS). ' .
+			'Can be removed completely in 1.44, assuming 1.43 is an LTS release.'
 	];
 
 	/**

includes/config-schema.php

@@ -2003,7 +2003,6 @@ return [
 			],
 			'SpecialPages' => [
 			],
-			'AutoloadAttemptLowercase' => false,
 			'ExtensionCredits' => [
 			],
 			'Hooks' => [
@@ -3216,9 +3215,6 @@ return [
 				'type' => 'boolean',
 			],
 		],
-		'AutoloadAttemptLowercase' => [
-			'deprecated' => 'since 1.35',
-		],
 		'JobBackoffThrottling' => [
 			'additionalProperties' => [
 				'type' => 'number',
@@ -3261,5 +3257,6 @@ return [
 	'obsolete-config' => [
 		'MangleFlashPolicy' => 'Since 1.39; no longer has any effect.',
 		'EnableOpenSearchSuggest' => 'Since 1.35, no longer used',
+		'AutoloadAttemptLowercase' => 'Since 1.40; no longer has any effect.',
 	],
 ];

includes/config-vars.php

@@ -3843,13 +3843,6 @@ $wgValidSkinNames = null;
  */
 $wgSpecialPages = null;
 
-/**
- * Config variable stub for the AutoloadAttemptLowercase setting, for use by phpdoc and IDEs.
- * @see MediaWiki\MainConfigSchema::AutoloadAttemptLowercase
- * @deprecated since 1.35
- */
-$wgAutoloadAttemptLowercase = null;
-
 /**
  * Config variable stub for the ExtensionCredits setting, for use by phpdoc and IDEs.
  * @see MediaWiki\MainConfigSchema::ExtensionCredits

tests/phpunit/MediaWikiUnitTestCase.php

@@ -56,7 +56,6 @@ abstract class MediaWikiUnitTestCase extends TestCase {
 			'wgAutoloadLocalClasses',
 			// Need for LoggerFactory. Default is NullSpi.
 			'wgMWLoggerDefaultSpi',
-			'wgAutoloadAttemptLowercase',
 			'wgLegalTitleChars',
 			'wgDevelopmentWarnings',
 			// Dependency of wfParseUrl()

tests/phpunit/data/autoloader/TestAutoloadedCamlClass.php

@@ -1,4 +0,0 @@
-<?php
-
-class TestAutoloadedCamlClass {
-}

tests/phpunit/data/autoloader/TestAutoloadedSerializedClass.php

@@ -1,4 +0,0 @@
-<?php
-
-class TestAutoloadedSerializedClass {
-}

tests/phpunit/includes/AutoLoaderTest.php

@@ -1,6 +1,5 @@
 <?php
 
-use MediaWiki\MainConfigNames;
 use Wikimedia\TestingAccessWrapper;
 
 /**
@@ -14,16 +13,10 @@ class AutoLoaderTest extends MediaWikiIntegrationTestCase {
 	protected function setUp(): void {
 		parent::setUp();
 
-		// Fancy dance to trigger a rebuild of AutoLoader::$autoloadLocalClassesLower
 		$this->mergeMwGlobalArrayValue( 'wgAutoloadLocalClasses', [
 			'TestAutoloadedLocalClass' =>
 				__DIR__ . '/../data/autoloader/TestAutoloadedLocalClass.php',
-			'TestAutoloadedCamlClass' =>
-				__DIR__ . '/../data/autoloader/TestAutoloadedCamlClass.php',
-			'TestAutoloadedSerializedClass' =>
-				__DIR__ . '/../data/autoloader/TestAutoloadedSerializedClass.php',
 		] );
-		AutoLoader::resetAutoloadLocalClassesLower();
 		$this->mergeMwGlobalArrayValue( 'wgAutoloadClasses', [
 			'TestAutoloadedClass' => __DIR__ . '/../data/autoloader/TestAutoloadedClass.php',
 		] );
@@ -63,24 +56,6 @@ class AutoLoaderTest extends MediaWikiIntegrationTestCase {
 		$this->assertTrue( class_exists( 'TestAutoloadedClass' ) );
 	}
 
-	public function testWrongCaseClass() {
-		$this->overrideConfigValue( MainConfigNames::AutoloadAttemptLowercase, true );
-
-		$this->assertTrue( class_exists( 'testautoLoadedcamlCLASS' ) );
-	}
-
-	public function testWrongCaseSerializedClass() {
-		$this->overrideConfigValue( MainConfigNames::AutoloadAttemptLowercase, true );
-
-		$dummySer = 'O:29:"testautoloadedserializedclass":0:{}';
-		$dummy = unserialize( $dummySer );
-		$this->assertSame(
-			get_class( $dummy ),
-			TestAutoloadedSerializedClass::class,
-			'load class case-insensitively'
-		);
-	}
-
 	public function testPsr4() {
 		$this->assertTrue( class_exists( 'Test\\MediaWiki\\AutoLoader\\TestFooBar' ) );
 	}