From: jenkins-bot <jenkins-bot@gerrit.wikimedia.org>
Date: Fri, 19 Aug 2016 19:39:17 +0000 (+0000)
Subject: Merge "Allow requiring cache size for page props"
X-Git-Tag: 1.31.0-rc.0~5988
X-Git-Url: http://git.cyclocoop.org/%7B%24admin_url%7Dmes_infos.php?a=commitdiff_plain;h=ded03d70579e8877f2144f0c24a1432d99ecaddd;hp=5e2376eb94f8d043283e8acc3c74ae93fba1da44;p=lhc%2Fweb%2Fwiklou.git

Merge "Allow requiring cache size for page props"
---

diff --git a/RELEASE-NOTES-1.28 b/RELEASE-NOTES-1.28
index f6c3530316..eac4e2c32f 100644
--- a/RELEASE-NOTES-1.28
+++ b/RELEASE-NOTES-1.28
@@ -61,6 +61,13 @@ production.
 * The following response properties from action=login, deprecated in 1.27, are
   now removed: lgtoken, cookieprefix, sessionid. Clients should handle cookies
   to properly manage session state.
+* Submitting the lgtoken and lgpassword parameters in the query string to
+  action=login is now deprecated and outputs a warning. They should be submitted
+  in the POST body instead.
+* Submitting sensitive authentication request parameters to action=clientlogin,
+  action=createaccount, action=linkaccount, and action=changeauthenticationdata
+  in the query string is now deprecated and outputs a warning. They should be
+  submitted in the POST body instead.
 
 === Action API internal changes in 1.28 ===
 * Added a new hook, 'ApiMakeParserOptions', to allow extensions to better
diff --git a/autoload.php b/autoload.php
index fc6577ef14..e37a011093 100644
--- a/autoload.php
+++ b/autoload.php
@@ -372,6 +372,7 @@ $wgAutoloadLocalClasses = [
 	'DoubleRedirectsPage' => __DIR__ . '/includes/specials/SpecialDoubleRedirects.php',
 	'DoubleReplacer' => __DIR__ . '/includes/libs/replacers/DoubleReplacer.php',
 	'DummyLinker' => __DIR__ . '/includes/DummyLinker.php',
+	'DummySearchIndexFieldDefinition' => __DIR__ . '/includes/search/DummySearchIndexFieldDefinition.php',
 	'DummyTermColorer' => __DIR__ . '/maintenance/term/MWTerm.php',
 	'Dump7ZipOutput' => __DIR__ . '/includes/export/Dump7ZipOutput.php',
 	'DumpBZip2Output' => __DIR__ . '/includes/export/DumpBZip2Output.php',
@@ -857,6 +858,7 @@ $wgAutoloadLocalClasses = [
 	'MediaWiki\\Logger\\NullSpi' => __DIR__ . '/includes/debug/logger/NullSpi.php',
 	'MediaWiki\\Logger\\Spi' => __DIR__ . '/includes/debug/logger/Spi.php',
 	'MediaWiki\\MediaWikiServices' => __DIR__ . '/includes/MediaWikiServices.php',
+	'MediaWiki\\Search\\ParserOutputSearchDataExtractor' => __DIR__ . '/includes/search/ParserOutputSearchDataExtractor.php',
 	'MediaWiki\\Services\\CannotReplaceActiveServiceException' => __DIR__ . '/includes/Services/CannotReplaceActiveServiceException.php',
 	'MediaWiki\\Services\\ContainerDisabledException' => __DIR__ . '/includes/Services/ContainerDisabledException.php',
 	'MediaWiki\\Services\\DestructibleService' => __DIR__ . '/includes/Services/DestructibleService.php',
diff --git a/includes/OutputPage.php b/includes/OutputPage.php
index f5a37d460a..eb3040cd28 100644
--- a/includes/OutputPage.php
+++ b/includes/OutputPage.php
@@ -163,6 +163,9 @@ class OutputPage extends ContextSource {
 	/** @var string */
 	private $rlUserModuleState;
 
+	/** @var array */
+	private $rlExemptStyleModules;
+
 	/** @var array */
 	protected $mJsConfigVars = [];
 
@@ -2660,30 +2663,64 @@ class OutputPage extends ContextSource {
 	public function getRlClient() {
 		if ( !$this->rlClient ) {
 			$context = $this->getRlClientContext();
-			$userModule = $this->getResourceLoader()->getModule( 'user' );
-			// Manually handled by getBottomScripts()
-			$userState = $userModule->isKnownEmpty( $context ) && !$this->isUserModulePreview()
-				? 'ready'
-				: 'loading';
-			$this->rlUserModuleState = $userState;
-
+			$rl = $this->getResourceLoader();
 			$this->addModules( [
 				'user.options',
 				'user.tokens',
 			] );
+			$this->addModuleStyles( [
+				'site.styles',
+				'noscript',
+				'user.styles',
+				'user.cssprefs',
+			] );
+
+			// Prepare exempt modules for buildExemptModules()
+			$exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
+			$exemptStates = [];
+			$moduleStyles = array_filter( $this->getModuleStyles( /*filter*/ true ),
+				function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
+					$module = $rl->getModule( $name );
+					if ( $module ) {
+						$group = $module->getGroup();
+						if ( $name === 'user.styles' && $this->isUserCssPreview() ) {
+							$exemptStates[$name] = 'ready';
+							// Special case in buildExemptModules()
+							return false;
+						}
+						if ( $name === 'site.styles' ) {
+							// HACK: Technically, 'site.styles' isn't in a separate request group.
+							// But, in order to ensure its styles are in the right position,
+							// pretend it's in a group called 'site'.
+							$group = 'site';
+						}
+						if ( isset( $exemptGroups[$group] ) ) {
+							$exemptStates[$name] = 'ready';
+							if ( !$module->isKnownEmpty( $context ) ) {
+								// E.g. Don't output empty <styles>
+								$exemptGroups[$group][] = $name;
+							}
+							return false;
+						}
+					}
+					return true;
+				}
+			);
+			$this->rlExemptStyleModules = $exemptGroups;
+
+			// Manually handled by getBottomScripts()
+			$userModule = $rl->getModule( 'user' );
+			$userState = $userModule->isKnownEmpty( $context ) && !$this->isUserJsPreview()
+				? 'ready'
+				: 'loading';
+			$this->rlUserModuleState = $exemptStates['user'] = $userState;
+
 			$rlClient = new ResourceLoaderClientHtml( $context, $this->getTarget() );
 			$rlClient->setConfig( $this->getJSVars() );
 			$rlClient->setModules( $this->getModules( /*filter*/ true ) );
-			$rlClient->setModuleStyles( $this->getModuleStyles( /*filter*/ true ) );
+			$rlClient->setModuleStyles( $moduleStyles );
 			$rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
-			$rlClient->setExemptStates( [
-				'user' => $userState,
-				// Manually handled by buildExemptModules() and getBottomScripts()
-				'site.styles' => 'ready',
-				'noscript' => 'ready',
-				'user.cssprefs' => 'ready',
-				'user.styles' => 'ready',
-			] );
+			$rlClient->setExemptStates( $exemptStates );
 			$this->rlClient = $rlClient;
 		}
 		return $this->rlClient;
@@ -2813,8 +2850,7 @@ class OutputPage extends ContextSource {
 		return WrappedString::join( "\n", $chunks );
 	}
 
-	/** @return bool */
-	private function isUserModulePreview() {
+	private function isUserJsPreview() {
 		return $this->getConfig()->get( 'AllowUserJs' )
 			&& $this->getUser()->isLoggedIn()
 			&& $this->getTitle()
@@ -2822,6 +2858,14 @@ class OutputPage extends ContextSource {
 			&& $this->userCanPreview();
 	}
 
+	private function isUserCssPreview() {
+		return $this->getConfig()->get( 'AllowUserCss' )
+			&& $this->getUser()->isLoggedIn()
+			&& $this->getTitle()
+			&& $this->getTitle()->isCssSubpage()
+			&& $this->userCanPreview();
+	}
+
 	/**
 	 * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
 	 * legacy scripts ($this->mScripts), and user JS.
@@ -2841,7 +2885,7 @@ class OutputPage extends ContextSource {
 		//   ensures execution is scheduled after the "site" module.
 		// - Don't load if module state is already resolved as "ready".
 		if ( $this->rlUserModuleState === 'loading' ) {
-			if ( $this->isUserModulePreview() ) {
+			if ( $this->isUserJsPreview() ) {
 				$chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
 					[ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
 				);
@@ -3414,19 +3458,11 @@ class OutputPage extends ContextSource {
 
 		$resourceLoader = $this->getResourceLoader();
 		$chunks = [];
-		// Things that should be appended after the other link and style chunks
+		// Things that go after the ResourceLoaderDynamicStyles marker
 		$append = [];
-		$moduleStyles = [
-			'site.styles',
-			'noscript'
-		];
 
-		// Exempt 'user' styles module.
-		// - May need excludepages for live preview.
-		// - Position after ResourceLoaderDynamicStyles marker
-		if ( $this->getConfig()->get( 'AllowUserCss' ) && $this->getTitle()->isCssSubpage()
-			&& $this->userCanPreview()
-		) {
+		// Exempt 'user' styles module (may need 'excludepages' for live preview)
+		if ( $this->isUserCssPreview() ) {
 			$append[] = $this->makeResourceLoaderLink(
 				'user.styles',
 				ResourceLoaderModule::TYPE_STYLES,
@@ -3440,60 +3476,26 @@ class OutputPage extends ContextSource {
 				$previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
 			}
 			$append[] = Html::inlineStyle( $previewedCSS );
-		} else {
-			$module = $this->getResourceLoader()->getModule( 'user.styles' );
-			if ( !$module->isKnownEmpty( $this->getRlClientContext() ) ) {
-				// Load styles normally
-				$moduleStyles[] = 'user.styles';
-			}
-		}
-
-		// Exempt 'user.cssprefs' module
-		// - Position after ResourceLoaderDynamicStyles marker
-		$moduleStyles[] = 'user.cssprefs';
-
-		$groups = [
-			'other' => [],
-			'site' => [],
-			'noscript' => [],
-			'private' => [],
-			'user' => [],
-		];
-		foreach ( $moduleStyles as $name ) {
-			$module = $resourceLoader->getModule( $name );
-			if ( !$module || $module->isKnownEmpty( $this->getRlClientContext() ) ) {
-				// E.g. Don't output empty <styles> for user.cssprefs
-				continue;
-			}
-			if ( $name === 'site.styles' ) {
-				// HACK: Technically, the 'site.styles' module isn't in a separate request group.
-				// But, in order to ensure its styles are in the right position after the marker,
-				// pretend it's in a group called 'site'.
-				$groups['site'][] = $name;
-				continue;
-			}
-			$group = $module->getGroup();
-			// Use "other" in case. All exempt modules are in one of the known groups though.
-			$groups[isset( $groups[$group] ) ? $group : 'other'][] = $name;
 		}
 
-		// We want site, private and user styles to override dynamically added
-		// styles from modules, but we want dynamically added styles to override
-		// statically added styles from other modules. So the order has to be
-		// other, dynamic, site, private, user. Add statically added styles for
-		// other modules
+		// We want site, private and user styles to override dynamically added styles from
+		// general modules, but we want dynamically added styles to override statically added
+		// style modules. So the order has to be:
+		// - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
+		// - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
+		// - ResourceLoaderDynamicStyles marker
+		// - site/private/user styles
 
 		// Add legacy styles added through addStyle()/addInlineStyle() here
 		$chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
 
-		// Client-side mw.loader will inject dynamic styles before this marker.
 		$chunks[] = Html::element(
 			'meta',
 			[ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
 		);
 
-		foreach ( [ 'other', 'site', 'noscript', 'private', 'user' ] as $group ) {
-			$chunks[] = $this->makeResourceLoaderLink( $groups[$group],
+		foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
+			$chunks[] = $this->makeResourceLoaderLink( $moduleNames,
 				ResourceLoaderModule::TYPE_STYLES
 			);
 		}
@@ -3813,9 +3815,6 @@ class OutputPage extends ContextSource {
 			'oojs-ui.styles.textures',
 			'mediawiki.widgets.styles',
 		] );
-		// Used by 'skipFunction' of the four 'oojs-ui.styles.*' modules. Please don't treat this as a
-		// public API or you'll be severely disappointed when T87871 is fixed and it disappears.
-		$this->addMeta( 'X-OOUI-PHP', '1' );
 	}
 
 	/**
diff --git a/includes/api/ApiAuthManagerHelper.php b/includes/api/ApiAuthManagerHelper.php
index c970f932d7..a4f54ee6d8 100644
--- a/includes/api/ApiAuthManagerHelper.php
+++ b/includes/api/ApiAuthManagerHelper.php
@@ -157,8 +157,13 @@ class ApiAuthManagerHelper {
 
 		// Collect the fields for all the requests
 		$fields = [];
+		$sensitive = [];
 		foreach ( $reqs as $req ) {
-			$fields += (array)$req->getFieldInfo();
+			$info = (array)$req->getFieldInfo();
+			$fields += $info;
+			$sensitive += array_filter( $info, function ( $opts ) {
+				return !empty( $opts['sensitive'] );
+			} );
 		}
 
 		// Extract the request data for the fields and mark those request
@@ -166,6 +171,16 @@ class ApiAuthManagerHelper {
 		$data = array_intersect_key( $this->module->getRequest()->getValues(), $fields );
 		$this->module->getMain()->markParamsUsed( array_keys( $data ) );
 
+		if ( $sensitive ) {
+			try {
+				$this->module->requirePostedParameters( array_keys( $sensitive ), 'noprefix' );
+			} catch ( UsageException $ex ) {
+				// Make this a warning for now, upgrade to an error in 1.29.
+				$this->module->setWarning( $ex->getMessage() );
+				$this->module->logFeatureUsage( $this->module->getModuleName() . '-params-in-query-string' );
+			}
+		}
+
 		return AuthenticationRequest::loadRequestsFromSubmission( $reqs, $data );
 	}
 
@@ -326,6 +341,7 @@ class ApiAuthManagerHelper {
 			$this->formatMessage( $ret, 'label', $field['label'] );
 			$this->formatMessage( $ret, 'help', $field['help'] );
 			$ret['optional'] = !empty( $field['optional'] );
+			$ret['sensitive'] = !empty( $field['sensitive'] );
 
 			$retFields[$name] = $ret;
 		}
diff --git a/includes/api/ApiBase.php b/includes/api/ApiBase.php
index 4a1a520f12..fcb748c202 100644
--- a/includes/api/ApiBase.php
+++ b/includes/api/ApiBase.php
@@ -776,6 +776,39 @@ abstract class ApiBase extends ContextSource {
 		}
 	}
 
+	/**
+	 * Die if any of the specified parameters were found in the query part of
+	 * the URL rather than the post body.
+	 * @since 1.28
+	 * @param string[] $params Parameters to check
+	 * @param string $prefix Set to 'noprefix' to skip calling $this->encodeParamName()
+	 */
+	public function requirePostedParameters( $params, $prefix = 'prefix' ) {
+		// Skip if $wgDebugAPI is set or we're in internal mode
+		if ( $this->getConfig()->get( 'DebugAPI' ) || $this->getMain()->isInternalMode() ) {
+			return;
+		}
+
+		$queryValues = $this->getRequest()->getQueryValues();
+		$badParams = [];
+		foreach ( $params as $param ) {
+			if ( $prefix !== 'noprefix' ) {
+				$param = $this->encodeParamName( $param );
+			}
+			if ( array_key_exists( $param, $queryValues ) ) {
+				$badParams[] = $param;
+			}
+		}
+
+		if ( $badParams ) {
+			$this->dieUsage(
+				'The following parameters were found in the query string, but must be in the POST body: '
+					. join( ', ', $badParams ),
+				'mustpostparams'
+			);
+		}
+	}
+
 	/**
 	 * Callback function used in requireOnlyOneParameter to check whether required parameters are set
 	 *
@@ -2197,7 +2230,7 @@ abstract class ApiBase extends ContextSource {
 	 * analysis.
 	 * @param string $feature Feature being used.
 	 */
-	protected function logFeatureUsage( $feature ) {
+	public function logFeatureUsage( $feature ) {
 		$request = $this->getRequest();
 		$s = '"' . addslashes( $feature ) . '"' .
 			' "' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) . '"' .
diff --git a/includes/api/ApiLogin.php b/includes/api/ApiLogin.php
index 28937f7873..9bc0b3a433 100644
--- a/includes/api/ApiLogin.php
+++ b/includes/api/ApiLogin.php
@@ -70,6 +70,14 @@ class ApiLogin extends ApiBase {
 			return;
 		}
 
+		try {
+			$this->requirePostedParameters( [ 'password', 'token' ] );
+		} catch ( UsageException $ex ) {
+			// Make this a warning for now, upgrade to an error in 1.29.
+			$this->setWarning( $ex->getMessage() );
+			$this->logFeatureUsage( 'login-params-in-query-string' );
+		}
+
 		$params = $this->extractRequestParams();
 
 		$result = [];
diff --git a/includes/api/ApiMain.php b/includes/api/ApiMain.php
index 565e829f79..22b079dee1 100644
--- a/includes/api/ApiMain.php
+++ b/includes/api/ApiMain.php
@@ -1103,18 +1103,7 @@ class ApiMain extends ApiBase {
 				$this->dieUsageMsg( [ 'missingparam', 'token' ] );
 			}
 
-			if ( !$this->getConfig()->get( 'DebugAPI' ) &&
-				array_key_exists(
-					$module->encodeParamName( 'token' ),
-					$this->getRequest()->getQueryValues()
-				)
-			) {
-				$this->dieUsage(
-					"The '{$module->encodeParamName( 'token' )}' parameter was " .
-						'found in the query string, but must be in the POST body',
-					'mustposttoken'
-				);
-			}
+			$module->requirePostedParameters( [ 'token' ] );
 
 			if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
 				$this->dieUsageMsg( 'sessionfailure' );
diff --git a/includes/api/ApiQueryBacklinksprop.php b/includes/api/ApiQueryBacklinksprop.php
index 3810e90f13..236fb9e06c 100644
--- a/includes/api/ApiQueryBacklinksprop.php
+++ b/includes/api/ApiQueryBacklinksprop.php
@@ -53,6 +53,7 @@ class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {
 			'code' => 'lh',
 			'prefix' => 'pl',
 			'linktable' => 'pagelinks',
+			'indexes' => [ 'pl_namespace', 'pl_backlinks_namespace' ],
 			'from_namespace' => true,
 			'showredirects' => true,
 		],
@@ -60,6 +61,7 @@ class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {
 			'code' => 'ti',
 			'prefix' => 'tl',
 			'linktable' => 'templatelinks',
+			'indexes' => [ 'tl_namespace', 'tl_backlinks_namespace' ],
 			'from_namespace' => true,
 			'showredirects' => true,
 		],
@@ -67,6 +69,7 @@ class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {
 			'code' => 'fu',
 			'prefix' => 'il',
 			'linktable' => 'imagelinks',
+			'indexes' => [ 'il_to', 'il_backlinks_namespace' ],
 			'from_namespace' => true,
 			'to_namespace' => NS_FILE,
 			'exampletitle' => 'File:Example.jpg',
@@ -249,6 +252,18 @@ class ApiQueryBacklinksprop extends ApiQueryGeneratorBase {
 		// Override any ORDER BY from above with what we calculated earlier.
 		$this->addOption( 'ORDER BY', array_keys( $sortby ) );
 
+		// MySQL's optimizer chokes if we have too many values in "$bl_title IN
+		// (...)" and chooses the wrong index, so specify the correct index to
+		// use for the query. See T139056 for details.
+		if ( !empty( $settings['indexes'] ) ) {
+			list( $idxNoFromNS, $idxWithFromNS ) = $settings['indexes'];
+			if ( $params['namespace'] !== null && !empty( $settings['from_namespace'] ) ) {
+				$this->addOption( 'USE INDEX', [ $settings['linktable'] => $idxWithFromNS ] );
+			} else {
+				$this->addOption( 'USE INDEX', [ $settings['linktable'] => $idxNoFromNS ] );
+			}
+		}
+
 		$this->addOption( 'LIMIT', $params['limit'] + 1 );
 
 		$res = $this->select( __METHOD__ );
diff --git a/includes/api/ApiUpload.php b/includes/api/ApiUpload.php
index fc2fd59056..ac817ba3c9 100644
--- a/includes/api/ApiUpload.php
+++ b/includes/api/ApiUpload.php
@@ -274,11 +274,17 @@ class ApiUpload extends ApiBase {
 					$this->dieStatusWithCode( $status, 'stashfailed' );
 				}
 
+				// We can only get warnings like 'duplicate' after concatenating the chunks
+				$warnings = $this->getApiWarnings();
+				if ( $warnings ) {
+					$result['warnings'] = $warnings;
+				}
+
 				// The fully concatenated file has a new filekey. So remove
 				// the old filekey and fetch the new one.
 				UploadBase::setSessionStatus( $this->getUser(), $filekey, false );
 				$this->mUpload->stash->removeFile( $filekey );
-				$filekey = $this->mUpload->getLocalFile()->getFileKey();
+				$filekey = $this->mUpload->getStashFile()->getFileKey();
 
 				$result['result'] = 'Success';
 			}
@@ -431,6 +437,12 @@ class ApiUpload extends ApiBase {
 			if ( isset( $progress['status']->value['verification'] ) ) {
 				$this->checkVerification( $progress['status']->value['verification'] );
 			}
+			if ( isset( $progress['status']->value['warnings'] ) ) {
+				$warnings = $this->transformWarnings( $progress['status']->value['warnings'] );
+				if ( $warnings ) {
+					$progress['warnings'] = $warnings;
+				}
+			}
 			unset( $progress['status'] ); // remove Status object
 			$this->getResult()->addValue( null, $this->getModuleName(), $progress );
 
@@ -735,7 +747,7 @@ class ApiUpload extends ApiBase {
 			$this->mParams['text'] = $this->mParams['comment'];
 		}
 
-		/** @var $file File */
+		/** @var $file LocalFile */
 		$file = $this->mUpload->getLocalFile();
 
 		// For preferences mode, we want to watch if 'watchdefault' is set,
diff --git a/includes/api/i18n/fr.json b/includes/api/i18n/fr.json
index 80eec50d93..4b42964c27 100644
--- a/includes/api/i18n/fr.json
+++ b/includes/api/i18n/fr.json
@@ -25,7 +25,8 @@
 			"Lbayle",
 			"Verdy p",
 			"Yasten",
-			"Trial"
+			"Trial",
+			"Pols12"
 		]
 	},
 	"apihelp-main-description": "<div class=\"hlist plainlinks api-main-links\">\n* [[mw:API:Main_page|Documentation]]\n* [[mw:API:FAQ|FAQ]]\n* [https://lists.wikimedia.org/mailman/listinfo/mediawiki-api Liste de diffusion]\n* [https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce Annonces de l’API]\n* [https://phabricator.wikimedia.org/maniphest/query/GebfyV4uCaLd/#R Bogues et demandes]\n</div>\n<strong>État :</strong> Toutes les fonctionnalités affichées sur cette page devraient fonctionner, mais l’API est encore en cours de développement et peut changer à tout moment. Inscrivez-vous à [https://lists.wikimedia.org/pipermail/mediawiki-api-announce/ la liste de diffusion mediawiki-api-announce] pour être informé des mises à jour.\n\n<strong>Requêtes erronées :</strong> Si des requêtes erronées sont envoyées à l’API, un en-tête HTTP sera renvoyé avec la clé « MediaWiki-API-Error ». La valeur de cet en-tête et le code d’erreur renvoyé prendront la même valeur. Pour plus d’information, voyez [[mw:API:Errors_and_warnings|API: Errors and warnings]].\n\n<strong>Test :</strong> Pour faciliter le test des requêtes de l’API, voyez [[Special:ApiSandbox]].",
@@ -1269,7 +1270,7 @@
 	"apihelp-stashedit-param-section": "Numéro de section. <kbd>0</kbd> pour la section du haut, <kbd>new</kbd> pour une nouvelle section.",
 	"apihelp-stashedit-param-sectiontitle": "Le titre pour une nouvelle section.",
 	"apihelp-stashedit-param-text": "Contenu de la page.",
-	"apihelp-stashedit-param-stashedtexthash": "A substituer par le hachage du contenu de la page venant d’une réserve antérieure.",
+	"apihelp-stashedit-param-stashedtexthash": "Empreinte du contenu de la page venant d’une réserve préalable à utiliser à la place.",
 	"apihelp-stashedit-param-contentmodel": "Modèle de contenu du nouveau contenu.",
 	"apihelp-stashedit-param-contentformat": "Format de sérialisation de contenu utilisé pour le texte saisi.",
 	"apihelp-stashedit-param-baserevid": "ID de révision de la révision de base.",
diff --git a/includes/api/i18n/zh-hans.json b/includes/api/i18n/zh-hans.json
index 037aff4526..860b7a771f 100644
--- a/includes/api/i18n/zh-hans.json
+++ b/includes/api/i18n/zh-hans.json
@@ -1027,7 +1027,7 @@
 	"apihelp-query+search-paramvalue-prop-snippet": "Adds a parsed snippet of the page.",
 	"apihelp-query+search-paramvalue-prop-titlesnippet": "Adds a parsed snippet of the page title.",
 	"apihelp-query+search-paramvalue-prop-redirectsnippet": "添加被解析的重定向标题的片段。",
-	"apihelp-query+search-paramvalue-prop-redirecttitle": "Adds the title of the matching redirect.",
+	"apihelp-query+search-paramvalue-prop-redirecttitle": "添加匹配的重定向的标题。",
 	"apihelp-query+search-paramvalue-prop-sectionsnippet": "Adds a parsed snippet of the matching section title.",
 	"apihelp-query+search-paramvalue-prop-sectiontitle": "Adds the title of the matching section.",
 	"apihelp-query+search-paramvalue-prop-categorysnippet": "Adds a parsed snippet of the matching category.",
@@ -1040,7 +1040,7 @@
 	"apihelp-query+search-param-enablerewrites": "启用内部查询重写。一些搜索后端可以重写查询到它认为会给出更好结果的地方，例如纠正拼写错误。",
 	"apihelp-query+search-example-simple": "搜索<kbd>meaning</kbd>。",
 	"apihelp-query+search-example-text": "搜索文本<kbd>meaning</kbd>。",
-	"apihelp-query+search-example-generator": "获得有关搜索<kbd>meaning</kbd>返回页面的页面信息。",
+	"apihelp-query+search-example-generator": "获取有关搜索<kbd>meaning</kbd>返回页面的页面信息。",
 	"apihelp-query+siteinfo-description": "返回有关网站的一般信息。",
 	"apihelp-query+siteinfo-param-prop": "要获取的信息：",
 	"apihelp-query+siteinfo-paramvalue-prop-general": "全部系统信息。",
diff --git a/includes/auth/AuthManager.php b/includes/auth/AuthManager.php
index b8c536ebd1..acdc01bfea 100644
--- a/includes/auth/AuthManager.php
+++ b/includes/auth/AuthManager.php
@@ -1688,13 +1688,9 @@ class AuthManager implements LoggerAwareInterface {
 			$logEntry->setParameters( [
 				'4::userid' => $user->getId(),
 			] );
-			$logid = $logEntry->insert();
+			$logEntry->insert();
 		}
 
-		// Commit database changes, so even if something else later blows up
-		// the newly-created user doesn't get lost.
-		wfGetLBFactory()->commitMasterChanges( __METHOD__ );
-
 		$trxProfiler->setSilenced( false );
 
 		if ( $login ) {
diff --git a/includes/auth/AuthenticationRequest.php b/includes/auth/AuthenticationRequest.php
index f6f949ec7c..2474b8b830 100644
--- a/includes/auth/AuthenticationRequest.php
+++ b/includes/auth/AuthenticationRequest.php
@@ -102,6 +102,8 @@ abstract class AuthenticationRequest {
 	 *  - label: (Message) Text suitable for a label in an HTML form
 	 *  - help: (Message) Text suitable as a description of what the field is
 	 *  - optional: (bool) If set and truthy, the field may be left empty
+	 *  - sensitive: (bool) If set and truthy, the field is considered sensitive. Code using the
+	 *      request should avoid exposing the value of the field.
 	 *
 	 * @return array As above
 	 */
@@ -315,6 +317,8 @@ abstract class AuthenticationRequest {
 					$options['optional'] = !empty( $options['optional'] );
 				}
 
+				$options['sensitive'] = !empty( $options['sensitive'] );
+
 				if ( !array_key_exists( $name, $merged ) ) {
 					$merged[$name] = $options;
 				} elseif ( $merged[$name]['type'] !== $options['type'] ) {
@@ -333,6 +337,7 @@ abstract class AuthenticationRequest {
 					}
 
 					$merged[$name]['optional'] = $merged[$name]['optional'] && $options['optional'];
+					$merged[$name]['sensitive'] = $merged[$name]['sensitive'] || $options['sensitive'];
 
 					// No way to merge 'value', 'image', 'help', or 'label', so just use
 					// the value from the first request.
diff --git a/includes/auth/EmailNotificationSecondaryAuthenticationProvider.php b/includes/auth/EmailNotificationSecondaryAuthenticationProvider.php
index d32640ea1d..a82f018d48 100644
--- a/includes/auth/EmailNotificationSecondaryAuthenticationProvider.php
+++ b/includes/auth/EmailNotificationSecondaryAuthenticationProvider.php
@@ -50,15 +50,16 @@ class EmailNotificationSecondaryAuthenticationProvider
 			&& $user->getEmail()
 			&& !$this->manager->getAuthenticationSessionData( 'no-email' )
 		) {
-			$status = $user->sendConfirmationMail();
-			$user->saveSettings();
-			if ( $status->isGood() ) {
-				// TODO show 'confirmemail_oncreate' success message
-			} else {
-				// TODO show 'confirmemail_sendfailed' error message
-				$this->logger->warning( 'Could not send confirmation email: ' .
-					$status->getWikiText( false, false, 'en' ) );
-			}
+			// TODO show 'confirmemail_oncreate'/'confirmemail_sendfailed' message
+			wfGetDB( DB_MASTER )->onTransactionIdle( function () use ( $user ) {
+				$user = $user->getInstanceForUpdate();
+				$status = $user->sendConfirmationMail();
+				$user->saveSettings();
+				if ( !$status->isGood() ) {
+					$this->logger->warning( 'Could not send confirmation email: ' .
+						$status->getWikiText( false, false, 'en' ) );
+				}
+			} );
 		}
 
 		return AuthenticationResponse::newPass();
diff --git a/includes/auth/PasswordAuthenticationRequest.php b/includes/auth/PasswordAuthenticationRequest.php
index 187c29ae9f..8550f3e211 100644
--- a/includes/auth/PasswordAuthenticationRequest.php
+++ b/includes/auth/PasswordAuthenticationRequest.php
@@ -53,6 +53,7 @@ class PasswordAuthenticationRequest extends AuthenticationRequest {
 				'type' => 'password',
 				'label' => wfMessage( $passwordLabel ),
 				'help' => wfMessage( 'authmanager-password-help' ),
+				'sensitive' => true,
 			],
 		];
 
@@ -68,6 +69,7 @@ class PasswordAuthenticationRequest extends AuthenticationRequest {
 				'type' => 'password',
 				'label' => wfMessage( $retypeLabel ),
 				'help' => wfMessage( 'authmanager-retype-help' ),
+				'sensitive' => true,
 			];
 		}
 
diff --git a/includes/auth/TemporaryPasswordPrimaryAuthenticationProvider.php b/includes/auth/TemporaryPasswordPrimaryAuthenticationProvider.php
index 46cbab5a3a..ed94c1ad2b 100644
--- a/includes/auth/TemporaryPasswordPrimaryAuthenticationProvider.php
+++ b/includes/auth/TemporaryPasswordPrimaryAuthenticationProvider.php
@@ -303,7 +303,11 @@ class TemporaryPasswordPrimaryAuthenticationProvider
 		);
 
 		if ( $sendMail ) {
-			$this->sendPasswordResetEmail( $req );
+			// Send email after DB commit
+			$dbw->onTransactionIdle( function () use ( $req ) {
+				/** @var TemporaryPasswordAuthenticationRequest $req */
+				$this->sendPasswordResetEmail( $req );
+			} );
 		}
 	}
 
@@ -370,7 +374,10 @@ class TemporaryPasswordPrimaryAuthenticationProvider
 		$this->providerChangeAuthenticationData( $req );
 
 		if ( $mailpassword ) {
-			$this->sendNewAccountEmail( $user, $creator, $req->password );
+			// Send email after DB commit
+			wfGetDB( DB_MASTER )->onTransactionIdle( function () use ( $user, $creator, $req ) {
+				$this->sendNewAccountEmail( $user, $creator, $req->password );
+			} );
 		}
 
 		return $mailpassword ? 'byemail' : null;
diff --git a/includes/content/ContentHandler.php b/includes/content/ContentHandler.php
index 7184980ede..41fdef5709 100644
--- a/includes/content/ContentHandler.php
+++ b/includes/content/ContentHandler.php
@@ -1,4 +1,7 @@
 <?php
+
+use MediaWiki\Search\ParserOutputSearchDataExtractor;
+
 /**
  * Base class for content handling.
  *
@@ -1156,62 +1159,19 @@ abstract class ContentHandler {
 	 *
 	 * @param string $event Event name
 	 * @param array $args Parameters passed to hook functions
-	 * @param bool $warn Whether to log a warning.
-	 *                    Default to self::$enableDeprecationWarnings.
-	 *                    May be set to false for testing.
+	 * @param string|null $deprecatedVersion Emit a deprecation notice
+	 *   when the hook is run for the provided version
 	 *
 	 * @return bool True if no handler aborted the hook
-	 *
-	 * @see ContentHandler::$enableDeprecationWarnings
 	 */
 	public static function runLegacyHooks( $event, $args = [],
-		$warn = null
+		$deprecatedVersion = null
 	) {
 
-		if ( $warn === null ) {
-			$warn = self::$enableDeprecationWarnings;
-		}
-
 		if ( !Hooks::isRegistered( $event ) ) {
 			return true; // nothing to do here
 		}
 
-		if ( $warn ) {
-			// Log information about which handlers are registered for the legacy hook,
-			// so we can find and fix them.
-
-			$handlers = Hooks::getHandlers( $event );
-			$handlerInfo = [];
-
-			MediaWiki\suppressWarnings();
-
-			foreach ( $handlers as $handler ) {
-				if ( is_array( $handler ) ) {
-					if ( is_object( $handler[0] ) ) {
-						$info = get_class( $handler[0] );
-					} else {
-						$info = $handler[0];
-					}
-
-					if ( isset( $handler[1] ) ) {
-						$info .= '::' . $handler[1];
-					}
-				} elseif ( is_object( $handler ) ) {
-					$info = get_class( $handler[0] );
-					$info .= '::on' . $event;
-				} else {
-					$info = $handler;
-				}
-
-				$handlerInfo[] = $info;
-			}
-
-			MediaWiki\restoreWarnings();
-
-			wfWarn( "Using obsolete hook $event via ContentHandler::runLegacyHooks()! Handlers: " .
-				implode( ', ', $handlerInfo ), 2 );
-		}
-
 		// convert Content objects to text
 		$contentObjects = [];
 		$contentTexts = [];
@@ -1229,7 +1189,7 @@ abstract class ContentHandler {
 		}
 
 		// call the hook functions
-		$ok = Hooks::run( $event, $args );
+		$ok = Hooks::run( $event, $args, $deprecatedVersion );
 
 		// see if the hook changed the text
 		foreach ( $contentTexts as $k => $orig ) {
@@ -1251,24 +1211,40 @@ abstract class ContentHandler {
 
 	/**
 	 * Get fields definition for search index
+	 *
+	 * @todo Expose title, redirect, namespace, text, source_text, text_bytes
+	 *       field mappings here. (see T142670 and T143409)
+	 *
 	 * @param SearchEngine $engine
 	 * @return SearchIndexField[] List of fields this content handler can provide.
 	 * @since 1.28
 	 */
 	public function getFieldsForSearchIndex( SearchEngine $engine ) {
-		/* Default fields:
-		/*
-		 * namespace
-		 * namespace_text
-		 * redirect
-		 * source_text
-		 * suggest
-		 * timestamp
-		 * title
-		 * text
-		 * text_bytes
-		 */
-		return [];
+		$fields['category'] = $engine->makeSearchFieldMapping(
+			'category',
+			SearchIndexField::INDEX_TYPE_TEXT
+		);
+
+		$fields['category']->setFlag( SearchIndexField::FLAG_CASEFOLD );
+
+		$fields['external_link'] = $engine->makeSearchFieldMapping(
+			'external_link',
+			SearchIndexField::INDEX_TYPE_KEYWORD
+		);
+
+		$fields['outgoing_link'] = $engine->makeSearchFieldMapping(
+			'outgoing_link',
+			SearchIndexField::INDEX_TYPE_KEYWORD
+		);
+
+		$fields['template'] = $engine->makeSearchFieldMapping(
+			'template',
+			SearchIndexField::INDEX_TYPE_KEYWORD
+		);
+
+		$fields['template']->setFlag( SearchIndexField::FLAG_CASEFOLD );
+
+		return $fields;
 	}
 
 	/**
@@ -1298,16 +1274,26 @@ abstract class ContentHandler {
 	 */
 	public function getDataForSearchIndex( WikiPage $page, ParserOutput $output,
 	                                       SearchEngine $engine ) {
-		$fields = [];
+		$fieldData = [];
 		$content = $page->getContent();
+
 		if ( $content ) {
+			$searchDataExtractor = new ParserOutputSearchDataExtractor();
+
+			$fieldData['category'] = $searchDataExtractor->getCategories( $output );
+			$fieldData['external_link'] = $searchDataExtractor->getExternalLinks( $output );
+			$fieldData['outgoing_link'] = $searchDataExtractor->getOutgoingLinks( $output );
+			$fieldData['template'] = $searchDataExtractor->getTemplates( $output );
+
 			$text = $content->getTextForSearchIndex();
-			$fields['text'] = $text;
-			$fields['source_text'] = $text;
-			$fields['text_bytes'] = $content->getSize();
+
+			$fieldData['text'] = $text;
+			$fieldData['source_text'] = $text;
+			$fieldData['text_bytes'] = $content->getSize();
 		}
-		Hooks::run( 'SearchDataForIndex', [ &$fields, $this, $page, $output, $engine ] );
-		return $fields;
+
+		Hooks::run( 'SearchDataForIndex', [ &$fieldData, $this, $page, $output, $engine ] );
+		return $fieldData;
 	}
 
 	/**
diff --git a/includes/content/WikiTextStructure.php b/includes/content/WikiTextStructure.php
index e83c213c0e..9768d3666e 100644
--- a/includes/content/WikiTextStructure.php
+++ b/includes/content/WikiTextStructure.php
@@ -58,50 +58,6 @@ class WikiTextStructure {
 		$this->parserOutput = $parserOutput;
 	}
 
-	/**
-	 * Get categories in the text.
-	 * @return string[]
-	 */
-	public function categories() {
-		$categories = [];
-		foreach ( array_keys( $this->parserOutput->getCategories() ) as $key ) {
-			$categories[] = Category::newFromName( $key )->getTitle()->getText();
-		}
-		return $categories;
-	}
-
-	/**
-	 * Get outgoing links.
-	 * @return string[]
-	 */
-	public function outgoingLinks() {
-		$outgoingLinks = [];
-		foreach ( $this->parserOutput->getLinks() as $linkedNamespace => $namespaceLinks ) {
-			foreach ( array_keys( $namespaceLinks ) as $linkedDbKey ) {
-				$outgoingLinks[] =
-					Title::makeTitle( $linkedNamespace, $linkedDbKey )->getPrefixedDBkey();
-			}
-		}
-		return $outgoingLinks;
-	}
-
-	/**
-	 * Get templates in the text.
-	 * @return string[]
-	 */
-	public function templates() {
-		$templates = [];
-		foreach ( $this->parserOutput->getTemplates() as $tNS => $templatesInNS ) {
-			foreach ( array_keys( $templatesInNS ) as $tDbKey ) {
-				$templateTitle = Title::makeTitleSafe( $tNS, $tDbKey );
-				if ( $templateTitle && $templateTitle->exists() ) {
-					$templates[] = $templateTitle->getPrefixedText();
-				}
-			}
-		}
-		return $templates;
-	}
-
 	/**
 	 * Get headings on the page.
 	 * @return string[]
diff --git a/includes/content/WikitextContentHandler.php b/includes/content/WikitextContentHandler.php
index 9baf64331d..1c46d28806 100644
--- a/includes/content/WikitextContentHandler.php
+++ b/includes/content/WikitextContentHandler.php
@@ -111,13 +111,6 @@ class WikitextContentHandler extends TextContentHandler {
 	public function getFieldsForSearchIndex( SearchEngine $engine ) {
 		$fields = parent::getFieldsForSearchIndex( $engine );
 
-		$fields['category'] =
-			$engine->makeSearchFieldMapping( 'category', SearchIndexField::INDEX_TYPE_TEXT );
-		$fields['category']->setFlag( SearchIndexField::FLAG_CASEFOLD );
-
-		$fields['external_link'] =
-			$engine->makeSearchFieldMapping( 'external_link', SearchIndexField::INDEX_TYPE_KEYWORD );
-
 		$fields['heading'] =
 			$engine->makeSearchFieldMapping( 'heading', SearchIndexField::INDEX_TYPE_TEXT );
 		$fields['heading']->setFlag( SearchIndexField::FLAG_SCORING );
@@ -130,13 +123,6 @@ class WikitextContentHandler extends TextContentHandler {
 		$fields['opening_text']->setFlag( SearchIndexField::FLAG_SCORING |
 		                                  SearchIndexField::FLAG_NO_HIGHLIGHT );
 
-		$fields['outgoing_link'] =
-			$engine->makeSearchFieldMapping( 'outgoing_link', SearchIndexField::INDEX_TYPE_KEYWORD );
-
-		$fields['template'] =
-			$engine->makeSearchFieldMapping( 'template', SearchIndexField::INDEX_TYPE_KEYWORD );
-		$fields['template']->setFlag( SearchIndexField::FLAG_CASEFOLD );
-
 		// FIXME: this really belongs in separate file handler but files
 		// do not have separate handler. Sadness.
 		$fields['file_text'] =
@@ -154,7 +140,11 @@ class WikitextContentHandler extends TextContentHandler {
 	protected function getFileText( Title $title ) {
 		$file = wfLocalFile( $title );
 		if ( $file && $file->exists() ) {
-			return $file->getHandler()->getEntireText( $file );
+			$handler = $file->getHandler();
+			if ( !$handler ) {
+				return null;
+			}
+			return $handler->getEntireText( $file );
 		}
 
 		return null;
@@ -165,11 +155,7 @@ class WikitextContentHandler extends TextContentHandler {
 		$fields = parent::getDataForSearchIndex( $page, $parserOutput, $engine );
 
 		$structure = new WikiTextStructure( $parserOutput );
-		$fields['external_link'] = array_keys( $parserOutput->getExternalLinks() );
-		$fields['category'] = $structure->categories();
 		$fields['heading'] = $structure->headings();
-		$fields['outgoing_link'] = $structure->outgoingLinks();
-		$fields['template'] = $structure->templates();
 		// text fields
 		$fields['opening_text'] = $structure->getOpeningText();
 		$fields['text'] = $structure->getMainText(); // overwrites one from ContentHandler
diff --git a/includes/db/DBConnRef.php b/includes/db/DBConnRef.php
index 53862b96da..4a7836355a 100644
--- a/includes/db/DBConnRef.php
+++ b/includes/db/DBConnRef.php
@@ -445,7 +445,7 @@ class DBConnRef implements IDatabase {
 		return $this->__call( __FUNCTION__, func_get_args() );
 	}
 
-	public function begin( $fname = __METHOD__ ) {
+	public function begin( $fname = __METHOD__, $mode = IDatabase::TRANSACTION_EXPLICIT ) {
 		return $this->__call( __FUNCTION__, func_get_args() );
 	}
 
diff --git a/includes/db/Database.php b/includes/db/Database.php
index 78975fff17..933bea60a9 100644
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -815,7 +815,7 @@ abstract class DatabaseBase implements IDatabase {
 		if ( !$this->mTrxLevel && $this->getFlag( DBO_TRX )
 			&& $this->isTransactableQuery( $sql )
 		) {
-			$this->begin( __METHOD__ . " ($fname)" );
+			$this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
 			$this->mTrxAutomatic = true;
 		}
 
@@ -2203,7 +2203,7 @@ abstract class DatabaseBase implements IDatabase {
 
 		$useTrx = !$this->mTrxLevel;
 		if ( $useTrx ) {
-			$this->begin( $fname );
+			$this->begin( $fname, self::TRANSACTION_INTERNAL );
 		}
 		try {
 			# Update any existing conflicting row(s)
@@ -2221,7 +2221,7 @@ abstract class DatabaseBase implements IDatabase {
 			throw $e;
 		}
 		if ( $useTrx ) {
-			$this->commit( $fname );
+			$this->commit( $fname, self::TRANSACTION_INTERNAL );
 		}
 
 		return $ok;
@@ -2520,7 +2520,7 @@ abstract class DatabaseBase implements IDatabase {
 			$this->mTrxPreCommitCallbacks[] = [ $callback, wfGetCaller() ];
 		} else {
 			// If no transaction is active, then make one for this callback
-			$this->begin( __METHOD__ );
+			$this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
 			try {
 				call_user_func( $callback );
 				$this->commit( __METHOD__ );
@@ -2628,7 +2628,7 @@ abstract class DatabaseBase implements IDatabase {
 
 	final public function startAtomic( $fname = __METHOD__ ) {
 		if ( !$this->mTrxLevel ) {
-			$this->begin( $fname );
+			$this->begin( $fname, self::TRANSACTION_INTERNAL );
 			$this->mTrxAutomatic = true;
 			// If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
 			// in all changes being in one transaction to keep requests transactional.
@@ -2658,51 +2658,36 @@ abstract class DatabaseBase implements IDatabase {
 	final public function doAtomicSection( $fname, callable $callback ) {
 		$this->startAtomic( $fname );
 		try {
-			call_user_func_array( $callback, [ $this, $fname ] );
+			$res = call_user_func_array( $callback, [ $this, $fname ] );
 		} catch ( Exception $e ) {
 			$this->rollback( $fname );
 			throw $e;
 		}
 		$this->endAtomic( $fname );
+
+		return $res;
 	}
 
-	final public function begin( $fname = __METHOD__ ) {
-		if ( $this->mTrxLevel ) { // implicit commit
+	final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
+		// Protect against mismatched atomic section, transaction nesting, and snapshot loss
+		if ( $this->mTrxLevel ) {
 			if ( $this->mTrxAtomicLevels ) {
-				// If the current transaction was an automatic atomic one, then we definitely have
-				// a problem. Same if there is any unclosed atomic level.
 				$levels = implode( ', ', $this->mTrxAtomicLevels );
-				throw new DBUnexpectedError(
-					$this,
-					"Got explicit BEGIN from $fname while atomic section(s) $levels are open."
-				);
+				$msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
+				throw new DBUnexpectedError( $this, $msg );
 			} elseif ( !$this->mTrxAutomatic ) {
-				// We want to warn about inadvertently nested begin/commit pairs, but not about
-				// auto-committing implicit transactions that were started by query() via DBO_TRX
-				throw new DBUnexpectedError(
-					$this,
-					"$fname: Transaction already in progress (from {$this->mTrxFname}), " .
-						" performing implicit commit!"
-				);
-			} elseif ( $this->mTrxDoneWrites ) {
-				// The transaction was automatic and has done write operations
-				throw new DBUnexpectedError(
-					$this,
-					"$fname: Automatic transaction with writes in progress" .
-						" (from {$this->mTrxFname}), performing implicit commit!\n"
-				);
-			}
-
-			$this->runOnTransactionPreCommitCallbacks();
-			$writeTime = $this->pendingWriteQueryDuration();
-			$this->doCommit( $fname );
-			if ( $this->mTrxDoneWrites ) {
-				$this->mDoneWrites = microtime( true );
-				$this->getTransactionProfiler()->transactionWritingOut(
-					$this->mServer, $this->mDBname, $this->mTrxShortId, $writeTime );
+				$msg = "$fname: Explicit transaction already active (from {$this->mTrxFname}).";
+				throw new DBUnexpectedError( $this, $msg );
+			} else {
+				// @TODO: make this an exception at some point
+				$msg = "$fname: Implicit transaction already active (from {$this->mTrxFname}).";
+				wfLogDBError( $msg );
+				return; // join the main transaction set
 			}
-
-			$this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
+		} elseif ( $this->getFlag( DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
+			// @TODO: make this an exception at some point
+			wfLogDBError( "$fname: Implicit transaction expected (DBO_TRX set)." );
+			return; // let any writes be in the main transaction
 		}
 
 		// Avoid fatals if close() was called
@@ -2742,7 +2727,7 @@ abstract class DatabaseBase implements IDatabase {
 			$levels = implode( ', ', $this->mTrxAtomicLevels );
 			throw new DBUnexpectedError(
 				$this,
-				"Got COMMIT while atomic sections $levels are still open"
+				"$fname: Got COMMIT while atomic sections $levels are still open."
 			);
 		}
 
@@ -2752,18 +2737,17 @@ abstract class DatabaseBase implements IDatabase {
 			} elseif ( !$this->mTrxAutomatic ) {
 				throw new DBUnexpectedError(
 					$this,
-					"$fname: Flushing an explicit transaction, getting out of sync!"
+					"$fname: Flushing an explicit transaction, getting out of sync."
 				);
 			}
 		} else {
 			if ( !$this->mTrxLevel ) {
-				wfWarn( "$fname: No transaction to commit, something got out of sync!" );
+				wfWarn( "$fname: No transaction to commit, something got out of sync." );
 				return; // nothing to do
 			} elseif ( $this->mTrxAutomatic ) {
-				throw new DBUnexpectedError(
-					$this,
-					"$fname: Explicit commit of implicit transaction."
-				);
+				// @TODO: make this an exception at some point
+				wfLogDBError( "$fname: Explicit commit of implicit transaction." );
+				return; // wait for the main transaction set commit round
 			}
 		}
 
@@ -2796,14 +2780,19 @@ abstract class DatabaseBase implements IDatabase {
 	}
 
 	final public function rollback( $fname = __METHOD__, $flush = '' ) {
-		if ( $flush !== self::FLUSHING_INTERNAL && $flush !== self::FLUSHING_ALL_PEERS ) {
+		if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
 			if ( !$this->mTrxLevel ) {
-				wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
 				return; // nothing to do
 			}
 		} else {
 			if ( !$this->mTrxLevel ) {
+				wfWarn( "$fname: No transaction to rollback, something got out of sync." );
 				return; // nothing to do
+			} elseif ( $this->getFlag( DBO_TRX ) ) {
+				throw new DBUnexpectedError(
+					$this,
+					"$fname: Expected mass rollback of all peer databases (DBO_TRX set)."
+				);
 			}
 		}
 
@@ -3297,13 +3286,29 @@ abstract class DatabaseBase implements IDatabase {
 	}
 
 	public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
+		if ( $this->writesOrCallbacksPending() ) {
+			// This only flushes transactions to clear snapshots, not to write data
+			throw new DBUnexpectedError(
+				$this,
+				"$fname: Cannot COMMIT to clear snapshot because writes are pending."
+			);
+		}
+
 		if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
 			return null;
 		}
 
 		$unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
-			$this->commit( __METHOD__, self::FLUSHING_INTERNAL );
-			$this->unlock( $lockKey, $fname );
+			if ( $this->trxLevel() ) {
+				// There is a good chance an exception was thrown, causing any early return
+				// from the caller. Let any error handler get a chance to issue rollback().
+				// If there isn't one, let the error bubble up and trigger server-side rollback.
+				$this->onTransactionResolution( function () use ( $lockKey, $fname ) {
+					$this->unlock( $lockKey, $fname );
+				} );
+			} else {
+				$this->unlock( $lockKey, $fname );
+			}
 		} );
 
 		$this->commit( __METHOD__, self::FLUSHING_INTERNAL );
diff --git a/includes/db/DatabasePostgres.php b/includes/db/DatabasePostgres.php
index 867aeb8705..1ecdd26088 100644
--- a/includes/db/DatabasePostgres.php
+++ b/includes/db/DatabasePostgres.php
@@ -149,7 +149,7 @@ class SavepointPostgres {
 		$this->didbegin = false;
 		/* If we are not in a transaction, we need to be for savepoint trickery */
 		if ( !$dbw->trxLevel() ) {
-			$dbw->begin( "FOR SAVEPOINT" );
+			$dbw->begin( "FOR SAVEPOINT", DatabasePostgres::TRANSACTION_INTERNAL );
 			$this->didbegin = true;
 		}
 	}
@@ -1207,7 +1207,7 @@ __INDEXATTR__;
 	 * @param string $desiredSchema
 	 */
 	function determineCoreSchema( $desiredSchema ) {
-		$this->begin( __METHOD__ );
+		$this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
 		if ( $this->schemaExists( $desiredSchema ) ) {
 			if ( in_array( $desiredSchema, $this->getSchemas() ) ) {
 				$this->mCoreSchema = $desiredSchema;
diff --git a/includes/db/IDatabase.php b/includes/db/IDatabase.php
index af024b8517..bdab09e7b5 100644
--- a/includes/db/IDatabase.php
+++ b/includes/db/IDatabase.php
@@ -40,6 +40,11 @@ interface IDatabase {
 	/** @var int Callback triggered by rollback */
 	const TRIGGER_ROLLBACK = 3;
 
+	/** @var string Transaction is requested by regular caller outside of the DB layer */
+	const TRANSACTION_EXPLICIT = '';
+	/** @var string Transaction is requested interally via DBO_TRX/startAtomic() */
+	const TRANSACTION_INTERNAL = 'implicit';
+
 	/** @var string Transaction operation comes from service managing all DBs */
 	const FLUSHING_ALL_PEERS = 'flush';
 	/** @var string Transaction operation comes from the database class internally */
@@ -1342,6 +1347,7 @@ interface IDatabase {
 	 *
 	 * @param string $fname Caller name (usually __METHOD__)
 	 * @param callable $callback Callback that issues DB updates
+	 * @return mixed $res Result of the callback (since 1.28)
 	 * @throws DBError
 	 * @throws RuntimeException
 	 * @throws UnexpectedValueException
@@ -1353,6 +1359,10 @@ interface IDatabase {
 	 * Begin a transaction. If a transaction is already in progress,
 	 * that transaction will be committed before the new transaction is started.
 	 *
+	 * Only call this from code with outer transcation scope.
+	 * See https://www.mediawiki.org/wiki/Database_transactions for details.
+	 * Nesting of transactions is not supported.
+	 *
 	 * Note that when the DBO_TRX flag is set (which is usually the case for web
 	 * requests, but not for maintenance scripts), any previous database query
 	 * will have started a transaction automatically.
@@ -1362,14 +1372,17 @@ interface IDatabase {
 	 * automatically because of the DBO_TRX flag.
 	 *
 	 * @param string $fname
+	 * @param string $mode A situationally valid IDatabase::TRANSACTION_* constant [optional]
 	 * @throws DBError
 	 */
-	public function begin( $fname = __METHOD__ );
+	public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT );
 
 	/**
 	 * Commits a transaction previously started using begin().
 	 * If no transaction is in progress, a warning is issued.
 	 *
+	 * Only call this from code with outer transcation scope.
+	 * See https://www.mediawiki.org/wiki/Database_transactions for details.
 	 * Nesting of transactions is not supported.
 	 *
 	 * @param string $fname
@@ -1390,7 +1403,11 @@ interface IDatabase {
 	 * Rollback a transaction previously started using begin().
 	 * If no transaction is in progress, a warning is issued.
 	 *
-	 * No-op on non-transactional databases.
+	 * Only call this from code with outer transcation scope.
+	 * See https://www.mediawiki.org/wiki/Database_transactions for details.
+	 * Nesting of transactions is not supported. If a serious unexpected error occurs,
+	 * throwing an Exception is preferrable, using a pre-installed error handler to trigger
+	 * rollback (in any case, failure to issue COMMIT will cause rollback server-side).
 	 *
 	 * @param string $fname
 	 * @param string $flush Flush flag, set to a situationally valid IDatabase::FLUSHING_*
@@ -1561,10 +1578,14 @@ interface IDatabase {
 	/**
 	 * Acquire a named lock, flush any transaction, and return an RAII style unlocker object
 	 *
+	 * Only call this from outer transcation scope and when only one DB will be affected.
+	 * See https://www.mediawiki.org/wiki/Database_transactions for details.
+	 *
 	 * This is suitiable for transactions that need to be serialized using cooperative locks,
 	 * where each transaction can see each others' changes. Any transaction is flushed to clear
 	 * out stale REPEATABLE-READ snapshot data. Once the returned object falls out of PHP scope,
-	 * any transaction will be committed and the lock will be released.
+	 * the lock will be released unless a transaction is active. If one is active, then the lock
+	 * will be released when it either commits or rolls back.
 	 *
 	 * If the lock acquisition failed, then no transaction flush happens, and null is returned.
 	 *
diff --git a/includes/htmlform/fields/HTMLFormFieldCloner.php b/includes/htmlform/fields/HTMLFormFieldCloner.php
index f39f54be1a..5d8f491881 100644
--- a/includes/htmlform/fields/HTMLFormFieldCloner.php
+++ b/includes/htmlform/fields/HTMLFormFieldCloner.php
@@ -257,7 +257,7 @@ class HTMLFormFieldCloner extends HTMLFormField {
 	 * @param array $values
 	 * @return string
 	 */
-	protected function getInputHTMLForKey( $key, $values ) {
+	protected function getInputHTMLForKey( $key, array $values ) {
 		$displayFormat = isset( $this->mParams['format'] )
 			? $this->mParams['format']
 			: $this->mParent->getDisplayFormat();
diff --git a/includes/jobqueue/jobs/AssembleUploadChunksJob.php b/includes/jobqueue/jobs/AssembleUploadChunksJob.php
index 1e804c4575..060cabb627 100644
--- a/includes/jobqueue/jobs/AssembleUploadChunksJob.php
+++ b/includes/jobqueue/jobs/AssembleUploadChunksJob.php
@@ -73,8 +73,12 @@ class AssembleUploadChunksJob extends Job {
 				return false;
 			}
 
+			// We can only get warnings like 'duplicate' after concatenating the chunks
+			$status = Status::newGood();
+			$status->value = [ 'warnings' => $upload->checkWarnings() ];
+
 			// We have a new filekey for the fully concatenated file
-			$newFileKey = $upload->getLocalFile()->getFileKey();
+			$newFileKey = $upload->getStashFile()->getFileKey();
 
 			// Remove the old stash file row and first chunk file
 			$upload->stash->removeFileNoAuth( $this->params['filekey'] );
@@ -95,7 +99,7 @@ class AssembleUploadChunksJob extends Job {
 					'stage' => 'assembling',
 					'filekey' => $newFileKey,
 					'imageinfo' => $imageInfo,
-					'status' => Status::newGood()
+					'status' => $status
 				]
 			);
 		} catch ( Exception $e ) {
diff --git a/includes/libs/objectcache/EmptyBagOStuff.php b/includes/libs/objectcache/EmptyBagOStuff.php
index 408212a1b3..3f66c06c9f 100644
--- a/includes/libs/objectcache/EmptyBagOStuff.php
+++ b/includes/libs/objectcache/EmptyBagOStuff.php
@@ -31,6 +31,10 @@ class EmptyBagOStuff extends BagOStuff {
 		return false;
 	}
 
+	public function add( $key, $value, $exp = 0 ) {
+		return true;
+	}
+
 	public function set( $key, $value, $exp = 0, $flags = 0 ) {
 		return true;
 	}
diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index 143042cfde..c40c819861 100644
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -33,6 +33,7 @@ use Psr\Log\NullLogger;
  * This class is intended for caching data from primary stores.
  * If the get() method does not return a value, then the caller
  * should query the new value and backfill the cache using set().
+ * The preferred way to do this logic is through getWithSetCallback().
  * When querying the store on cache miss, the closest DB replica
  * should be used. Try to avoid heavyweight DB master or quorum reads.
  * When the source data changes, a purge method should be called.
@@ -43,16 +44,23 @@ use Psr\Log\NullLogger;
  *
  * The simplest purge method is delete().
  *
- * Instances of this class must be configured to point to a valid
- * PubSub endpoint, and there must be listeners on the cache servers
- * that subscribe to the endpoint and update the caches.
+ * There are two supported ways to handle broadcasted operations:
+ *   - a) Configure the 'purge' EventRelayer to point to a valid PubSub endpoint
+ *        that has subscribed listeners on the cache servers applying the cache updates.
+ *   - b) Ignore the 'purge' EventRelayer configuration (default is NullEventRelayer)
+ *        and set up mcrouter as the underlying cache backend, using one of the memcached
+ *        BagOStuff classes as 'cache'. Use OperationSelectorRoute in the mcrouter settings
+ *        to configure 'set' and 'delete' operations to go to all DCs via AllAsyncRoute and
+ *        configure other operations to go to the local DC via PoolRoute (for reference,
+ *        see https://github.com/facebook/mcrouter/wiki/List-of-Route-Handles).
  *
- * Broadcasted operations like delete() and touchCheckKey() are done
- * synchronously in the local datacenter, but are relayed asynchronously.
- * This means that callers in other datacenters will see older values
- * for however many milliseconds the datacenters are apart. As with
- * any cache, this should not be relied on for cases where reads are
- * used to determine writes to source (e.g. non-cache) data stores.
+ * Broadcasted operations like delete() and touchCheckKey() are done asynchronously
+ * in all datacenters this way, though the local one should likely be near immediate.
+ *
+ * This means that callers in all datacenters may see older values for however many
+ * milliseconds that the purge took to reach that datacenter. As with any cache, this
+ * should not be relied on for cases where reads are used to determine writes to source
+ * (e.g. non-cache) data stores, except when reading immutable data.
  *
  * All values are wrapped in metadata arrays. Keys use a "WANCache:" prefix
  * to avoid collisions with keys that are not wrapped as metadata arrays. The
@@ -60,6 +68,7 @@ use Psr\Log\NullLogger;
  *   - a) "WANCache:v" : used for regular value keys
  *   - b) "WANCache:i" : used for temporarily storing values of tombstoned keys
  *   - c) "WANCache:t" : used for storing timestamp "check" keys
+ *   - d) "WANCache:m" : used for temporary mutex keys to avoid cache stampedes
  *
  * @ingroup Cache
  * @since 1.26
@@ -129,6 +138,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	const VALUE_KEY_PREFIX = 'WANCache:v:';
 	const INTERIM_KEY_PREFIX = 'WANCache:i:';
 	const TIME_KEY_PREFIX = 'WANCache:t:';
+	const MUTEX_KEY_PREFIX = 'WANCache:m:';
 
 	const PURGE_VAL_PREFIX = 'PURGED:';
 
@@ -456,8 +466,8 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 *
 	 * When using potentially long-running ACID transactions, a good pattern is
 	 * to use a pre-commit hook to issue the delete. This means that immediately
-	 * after commit, callers will see the tombstone in cache in the local datacenter
-	 * and in the others upon relay. It also avoids the following race condition:
+	 * after commit, callers will see the tombstone in cache upon purge relay.
+	 * It also avoids the following race condition:
 	 *   - a) T1 begins, changes a row, and calls delete()
 	 *   - b) The HOLDOFF_TTL passes, expiring the delete() tombstone
 	 *   - c) T2 starts, reads the row and calls set() due to a cache miss
@@ -495,18 +505,11 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 		$key = self::VALUE_KEY_PREFIX . $key;
 
 		if ( $ttl <= 0 ) {
-			// Update the local datacenter immediately
-			$ok = $this->cache->delete( $key );
 			// Publish the purge to all datacenters
-			$ok = $this->relayDelete( $key ) && $ok;
+			$ok = $this->relayDelete( $key );
 		} else {
-			// Update the local datacenter immediately
-			$ok = $this->cache->set( $key,
-				$this->makePurgeValue( microtime( true ), self::HOLDOFF_NONE ),
-				$ttl
-			);
 			// Publish the purge to all datacenters
-			$ok = $this->relayPurge( $key, $ttl, self::HOLDOFF_NONE ) && $ok;
+			$ok = $this->relayPurge( $key, $ttl, self::HOLDOFF_NONE );
 		}
 
 		return $ok;
@@ -559,8 +562,9 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * keys, the relevant "check" keys must be supplied for this to work.
 	 *
 	 * The "check" key essentially represents a last-modified field.
-	 * When touched, keys using it via get(), getMulti(), or getWithSetCallback()
-	 * will be invalidated. It is treated as being HOLDOFF_TTL seconds in the future
+	 * When touched, the field will be updated on all cache servers.
+	 * Keys using it via get(), getMulti(), or getWithSetCallback() will
+	 * be invalidated. It is treated as being HOLDOFF_TTL seconds in the future
 	 * by those methods to avoid race conditions where dependent keys get updated
 	 * with stale values (e.g. from a DB slave).
 	 *
@@ -569,7 +573,8 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * When a few important keys get a large number of hits, a high cache
 	 * time is usually desired as well as "lockTSE" logic. The resetCheckKey()
 	 * method is less appropriate in such cases since the "time since expiry"
-	 * cannot be inferred.
+	 * cannot be inferred, causing any get() after the reset to treat the key
+	 * as being "hot", resulting in more stale value usage.
 	 *
 	 * Note that "check" keys won't collide with other regular keys.
 	 *
@@ -582,14 +587,8 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * @return bool True if the item was purged or not found, false on failure
 	 */
 	final public function touchCheckKey( $key, $holdoff = self::HOLDOFF_TTL ) {
-		$key = self::TIME_KEY_PREFIX . $key;
-		// Update the local datacenter immediately
-		$ok = $this->cache->set( $key,
-			$this->makePurgeValue( microtime( true ), $holdoff ),
-			self::CHECK_KEY_TTL
-		);
 		// Publish the purge to all datacenters
-		return $this->relayPurge( $key, self::CHECK_KEY_TTL, $holdoff ) && $ok;
+		return $this->relayPurge( self::TIME_KEY_PREFIX . $key, self::CHECK_KEY_TTL, $holdoff );
 	}
 
 	/**
@@ -597,11 +596,14 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 *
 	 * This is similar to touchCheckKey() in that keys using it via get(), getMulti(),
 	 * or getWithSetCallback() will be invalidated. The differences are:
-	 *   - a) The timestamp will be deleted from all caches and lazily
+	 *   - a) The "check" key will be deleted from all caches and lazily
 	 *        re-initialized when accessed (rather than set everywhere)
 	 *   - b) Thus, dependent keys will be known to be invalid, but not
 	 *        for how long (they are treated as "just" purged), which
 	 *        effects any lockTSE logic in getWithSetCallback()
+	 *   - c) Since "check" keys are initialized only on the server the key hashes
+	 *        to, any temporary ejection of that server will cause the value to be
+	 *        seen as purged as a new server will initialize the "check" key.
 	 *
 	 * The advantage is that this does not place high TTL keys on every cache
 	 * server, making it better for code that will cache many different keys
@@ -620,11 +622,8 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * @return bool True if the item was purged or not found, false on failure
 	 */
 	final public function resetCheckKey( $key ) {
-		$key = self::TIME_KEY_PREFIX . $key;
-		// Update the local datacenter immediately
-		$ok = $this->cache->delete( $key );
 		// Publish the purge to all datacenters
-		return $this->relayDelete( $key ) && $ok;
+		return $this->relayDelete( self::TIME_KEY_PREFIX . $key );
 	}
 
 	/**
@@ -908,7 +907,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 		$lockAcquired = false;
 		if ( $useMutex ) {
 			// Acquire a datacenter-local non-blocking lock
-			if ( $this->cache->lock( $key, 0, self::LOCK_TTL ) ) {
+			if ( $this->cache->add( self::MUTEX_KEY_PREFIX . $key, 1, self::LOCK_TTL ) ) {
 				// Lock acquired; this thread should update the key
 				$lockAcquired = true;
 			} elseif ( $value !== false && $this->isValid( $value, $versioned, $asOf, $minTime ) ) {
@@ -945,11 +944,15 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 		if ( ( $isTombstone && $lockTSE > 0 ) && $value !== false && $ttl >= 0 ) {
 			$tempTTL = max( 1, (int)$lockTSE ); // set() expects seconds
 			$wrapped = $this->wrap( $value, $tempTTL, $asOf );
-			$this->cache->set( self::INTERIM_KEY_PREFIX . $key, $wrapped, $tempTTL );
-		}
-
-		if ( $lockAcquired ) {
-			$this->cache->unlock( $key );
+			// Avoid using set() to avoid pointless mcrouter broadcasting
+			$this->cache->merge(
+				self::INTERIM_KEY_PREFIX . $key,
+				function () use ( $wrapped ) {
+					return $wrapped;
+				},
+				$tempTTL,
+				1
+			);
 		}
 
 		if ( $value !== false && $ttl >= 0 ) {
@@ -958,6 +961,11 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 			$this->set( $key, $value, $ttl, $setOpts );
 		}
 
+		if ( $lockAcquired ) {
+			// Avoid using delete() to avoid pointless mcrouter broadcasting
+			$this->cache->changeTTL( self::MUTEX_KEY_PREFIX . $key, 1 );
+		}
+
 		return $value;
 	}
 
@@ -1045,17 +1053,25 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * @return bool Success
 	 */
 	protected function relayPurge( $key, $ttl, $holdoff ) {
-		$event = $this->cache->modifySimpleRelayEvent( [
-			'cmd' => 'set',
-			'key' => $key,
-			'val' => 'PURGED:$UNIXTIME$:' . (int)$holdoff,
-			'ttl' => max( $ttl, 1 ),
-			'sbt' => true, // substitute $UNIXTIME$ with actual microtime
-		] );
-
-		$ok = $this->purgeRelayer->notify( $this->purgeChannel, $event );
-		if ( !$ok ) {
-			$this->lastRelayError = self::ERR_RELAY;
+		if ( $this->purgeRelayer instanceof EventRelayerNull ) {
+			// This handles the mcrouter and the single-DC case
+			$ok = $this->cache->set( $key,
+				$this->makePurgeValue( microtime( true ), self::HOLDOFF_NONE ),
+				$ttl
+			);
+		} else {
+			$event = $this->cache->modifySimpleRelayEvent( [
+				'cmd' => 'set',
+				'key' => $key,
+				'val' => 'PURGED:$UNIXTIME$:' . (int)$holdoff,
+				'ttl' => max( $ttl, 1 ),
+				'sbt' => true, // substitute $UNIXTIME$ with actual microtime
+			] );
+
+			$ok = $this->purgeRelayer->notify( $this->purgeChannel, $event );
+			if ( !$ok ) {
+				$this->lastRelayError = self::ERR_RELAY;
+			}
 		}
 
 		return $ok;
@@ -1068,14 +1084,19 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 	 * @return bool Success
 	 */
 	protected function relayDelete( $key ) {
-		$event = $this->cache->modifySimpleRelayEvent( [
-			'cmd' => 'delete',
-			'key' => $key,
-		] );
-
-		$ok = $this->purgeRelayer->notify( $this->purgeChannel, $event );
-		if ( !$ok ) {
-			$this->lastRelayError = self::ERR_RELAY;
+		if ( $this->purgeRelayer instanceof EventRelayerNull ) {
+			// This handles the mcrouter and the single-DC case
+			$ok = $this->cache->delete( $key );
+		} else {
+			$event = $this->cache->modifySimpleRelayEvent( [
+				'cmd' => 'delete',
+				'key' => $key,
+			] );
+
+			$ok = $this->purgeRelayer->notify( $this->purgeChannel, $event );
+			if ( !$ok ) {
+				$this->lastRelayError = self::ERR_RELAY;
+			}
 		}
 
 		return $ok;
diff --git a/includes/resourceloader/ResourceLoaderImageModule.php b/includes/resourceloader/ResourceLoaderImageModule.php
index 3b3bdf7e11..43327c91cc 100644
--- a/includes/resourceloader/ResourceLoaderImageModule.php
+++ b/includes/resourceloader/ResourceLoaderImageModule.php
@@ -393,6 +393,8 @@ class ResourceLoaderImageModule extends ResourceLoaderModule {
 	public function getDefinitionSummary( ResourceLoaderContext $context ) {
 		$this->loadFromDefinition();
 		$summary = parent::getDefinitionSummary( $context );
+
+		$options = [];
 		foreach ( [
 			'localBasePath',
 			'images',
@@ -401,29 +403,27 @@ class ResourceLoaderImageModule extends ResourceLoaderModule {
 			'selectorWithoutVariant',
 			'selectorWithVariant',
 		] as $member ) {
-			$summary[$member] = $this->{$member};
+			$options[$member] = $this->{$member};
 		};
+
+		$summary[] = [
+			'options' => $options,
+			'fileHashes' => $this->getFileHashes( $context ),
+		];
 		return $summary;
 	}
 
 	/**
-	 * Get the last modified timestamp of this module.
-	 *
-	 * @param ResourceLoaderContext $context Context in which to calculate
-	 *     the modified time
-	 * @return int UNIX timestamp
+	 * Helper method for getDefinitionSummary.
 	 */
-	public function getModifiedTime( ResourceLoaderContext $context ) {
+	protected function getFileHashes( ResourceLoaderContext $context ) {
 		$this->loadFromDefinition();
 		$files = [];
 		foreach ( $this->getImages( $context ) as $name => $image ) {
 			$files[] = $image->getPath( $context );
 		}
-
 		$files = array_values( array_unique( $files ) );
-		$filesMtime = max( array_map( [ __CLASS__, 'safeFilemtime' ], $files ) );
-
-		return $filesMtime;
+		return array_map( [ __CLASS__, 'safeFileHash' ], $files );
 	}
 
 	/**
@@ -455,4 +455,11 @@ class ResourceLoaderImageModule extends ResourceLoaderModule {
 		$this->loadFromDefinition();
 		return $this->position;
 	}
+
+	/**
+	 * @return string
+	 */
+	public function getType() {
+		return self::LOAD_STYLES;
+	}
 }
diff --git a/includes/search/DummySearchIndexFieldDefinition.php b/includes/search/DummySearchIndexFieldDefinition.php
new file mode 100644
index 0000000000..a2a6760192
--- /dev/null
+++ b/includes/search/DummySearchIndexFieldDefinition.php
@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * Dummy implementation of SearchIndexFieldDefinition for testing purposes.
+ *
+ * @since 1.28
+ */
+class DummySearchIndexFieldDefinition extends SearchIndexFieldDefinition {
+
+	/**
+	 * @param SearchEngine $engine
+	 *
+	 * @return array
+	 */
+	public function getMapping( SearchEngine $engine ) {
+		$mapping = [
+			'name' => $this->name,
+			'type' => $this->type,
+			'flags' => $this->flags,
+			'subfields' => []
+		];
+
+		foreach ( $this->subfields as $subfield ) {
+			$mapping['subfields'][] = $subfield->getMapping();
+		}
+
+		return $mapping;
+	}
+
+}
diff --git a/includes/search/ParserOutputSearchDataExtractor.php b/includes/search/ParserOutputSearchDataExtractor.php
new file mode 100644
index 0000000000..df653f1240
--- /dev/null
+++ b/includes/search/ParserOutputSearchDataExtractor.php
@@ -0,0 +1,92 @@
+<?php
+
+namespace MediaWiki\Search;
+
+use Category;
+use ParserOutput;
+use Title;
+
+/**
+ * Extracts data from ParserOutput for indexing in the search engine.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @since 1.28
+ */
+class ParserOutputSearchDataExtractor {
+
+	/**
+	 * Get a list of categories, as an array with title text strings.
+	 *
+	 * @return string[]
+	 */
+	public function getCategories( ParserOutput $parserOutput ) {
+		$categories = [];
+
+		foreach ( $parserOutput->getCategoryLinks() as $key ) {
+			$categories[] = Category::newFromName( $key )->getTitle()->getText();
+		}
+
+		return $categories;
+	}
+
+	/**
+	 * Get a list of external links from ParserOutput, as an array of strings.
+	 *
+	 * @return string[]
+	 */
+	public function getExternalLinks( ParserOutput $parserOutput ) {
+		return array_keys( $parserOutput->getExternalLinks() );
+	}
+
+	/**
+	 * Get a list of outgoing wiki links (including interwiki links), as
+	 * an array of prefixed title strings.
+	 *
+	 * @return string[]
+	 */
+	public function getOutgoingLinks( ParserOutput $parserOutput ) {
+		$outgoingLinks = [];
+
+		foreach ( $parserOutput->getLinks() as $linkedNamespace => $namespaceLinks ) {
+			foreach ( array_keys( $namespaceLinks ) as $linkedDbKey ) {
+				$outgoingLinks[] =
+					Title::makeTitle( $linkedNamespace, $linkedDbKey )->getPrefixedDBkey();
+			}
+		}
+
+		return $outgoingLinks;
+	}
+
+	/**
+	 * Get a list of templates used in the ParserOutput content, as prefixed title strings
+	 *
+	 * @return string[]
+	 */
+	public function getTemplates( ParserOutput $parserOutput ) {
+		$templates = [];
+
+		foreach ( $parserOutput->getTemplates() as $tNS => $templatesInNS ) {
+			foreach ( array_keys( $templatesInNS ) as $tDbKey ) {
+				$templateTitle = Title::makeTitle( $tNS, $tDbKey );
+				$templates[] = $templateTitle->getPrefixedText();
+			}
+		}
+
+		return $templates;
+	}
+
+}
diff --git a/includes/search/SearchIndexFieldDefinition.php b/includes/search/SearchIndexFieldDefinition.php
index 3a86c82d0d..8a06b65ed7 100644
--- a/includes/search/SearchIndexFieldDefinition.php
+++ b/includes/search/SearchIndexFieldDefinition.php
@@ -2,8 +2,10 @@
 
 /**
  * Basic infrastructure of the field definition.
- * Specific engines will need to override it at least for getMapping,
- * but can reuse other parts.
+ *
+ * Specific engines should extend this class and at at least,
+ * override the getMapping method, but can reuse other parts.
+ *
  * @since 1.28
  */
 abstract class SearchIndexFieldDefinition implements SearchIndexField {
@@ -115,4 +117,12 @@ abstract class SearchIndexFieldDefinition implements SearchIndexField {
 		$this->subfields = $subfields;
 		return $this;
 	}
+
+	/**
+	 * @param SearchEngine $engine
+	 *
+	 * @return array
+	 */
+	abstract public function getMapping( SearchEngine $engine );
+
 }
diff --git a/includes/specials/SpecialSearch.php b/includes/specials/SpecialSearch.php
index 9690d45bc9..26b86f9762 100644
--- a/includes/specials/SpecialSearch.php
+++ b/includes/specials/SpecialSearch.php
@@ -100,6 +100,25 @@ class SpecialSearch extends SpecialPage {
 	 * @param string $par
 	 */
 	public function execute( $par ) {
+		$request = $this->getRequest();
+
+		// Fetch the search term
+		$search = str_replace( "\n", " ", $request->getText( 'search' ) );
+
+		// Historically search terms have been accepted not only in the search query
+		// parameter, but also as part of the primary url. This can have PII implications
+		// in releasing page view data. As such issue a 301 redirect to the correct
+		// URL.
+		if ( strlen( $par ) && !strlen( $search ) ) {
+			$query = $request->getValues();
+			unset( $query['title'] );
+			// Strip underscores from title parameter; most of the time we'll want
+			// text form here. But don't strip underscores from actual text params!
+			$query['search'] = str_replace( '_', ' ', $par );
+			$this->getOutput()->redirect( $this->getPageTitle()->getFullURL( $query ), 301 );
+			return;
+		}
+
 		$this->setHeaders();
 		$this->outputHeader();
 		$out = $this->getOutput();
@@ -110,15 +129,6 @@ class SpecialSearch extends SpecialPage {
 		] );
 		$this->addHelpLink( 'Help:Searching' );
 
-		// Strip underscores from title parameter; most of the time we'll want
-		// text form here. But don't strip underscores from actual text params!
-		$titleParam = str_replace( '_', ' ', $par );
-
-		$request = $this->getRequest();
-
-		// Fetch the search term
-		$search = str_replace( "\n", " ", $request->getText( 'search', $titleParam ) );
-
 		$this->load();
 		if ( !is_null( $request->getVal( 'nsRemember' ) ) ) {
 			$this->saveNamespaces();
diff --git a/includes/upload/UploadBase.php b/includes/upload/UploadBase.php
index ae16f70227..e2f7763251 100644
--- a/includes/upload/UploadBase.php
+++ b/includes/upload/UploadBase.php
@@ -44,7 +44,7 @@ abstract class UploadBase {
 	protected $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
 	protected $mTitle = false, $mTitleError = 0;
 	protected $mFilteredName, $mFinalExtension;
-	protected $mLocalFile, $mFileSize, $mFileProps;
+	protected $mLocalFile, $mStashFile, $mFileSize, $mFileProps;
 	protected $mBlackListedExtensions;
 	protected $mJavaDetected, $mSVGNSError;
 
@@ -912,7 +912,7 @@ abstract class UploadBase {
 	/**
 	 * Return the local file and initializes if necessary.
 	 *
-	 * @return LocalFile|UploadStashFile|null
+	 * @return LocalFile|null
 	 */
 	public function getLocalFile() {
 		if ( is_null( $this->mLocalFile ) ) {
@@ -923,6 +923,13 @@ abstract class UploadBase {
 		return $this->mLocalFile;
 	}
 
+	/**
+	 * @return UploadStashFile|null
+	 */
+	public function getStashFile() {
+		return $this->mStashFile;
+	}
+
 	/**
 	 * Like stashFile(), but respects extensions' wishes to prevent the stashing. verifyUpload() must
 	 * be called before calling this method (unless $isPartial is true).
@@ -997,7 +1004,7 @@ abstract class UploadBase {
 	protected function doStashFile( User $user = null ) {
 		$stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $user );
 		$file = $stash->stashFile( $this->mTempPath, $this->getSourceType() );
-		$this->mLocalFile = $file;
+		$this->mStashFile = $file;
 
 		return $file;
 	}
@@ -1975,18 +1982,16 @@ abstract class UploadBase {
 	 * @return array Image info
 	 */
 	public function getImageInfo( $result ) {
-		$file = $this->getLocalFile();
-		/** @todo This cries out for refactoring.
-		 *  We really want to say $file->getAllInfo(); here.
-		 * Perhaps "info" methods should be moved into files, and the API should
-		 * just wrap them in queries.
-		 */
-		if ( $file instanceof UploadStashFile ) {
+		$localFile = $this->getLocalFile();
+		$stashFile = $this->getStashFile();
+		// Calling a different API module depending on whether the file was stashed is less than optimal.
+		// In fact, calling API modules here at all is less than optimal. Maybe it should be refactored.
+		if ( $stashFile ) {
 			$imParam = ApiQueryStashImageInfo::getPropertyNames();
-			$info = ApiQueryStashImageInfo::getInfo( $file, array_flip( $imParam ), $result );
+			$info = ApiQueryStashImageInfo::getInfo( $stashFile, array_flip( $imParam ), $result );
 		} else {
 			$imParam = ApiQueryImageInfo::getPropertyNames();
-			$info = ApiQueryImageInfo::getInfo( $file, array_flip( $imParam ), $result );
+			$info = ApiQueryImageInfo::getInfo( $localFile, array_flip( $imParam ), $result );
 		}
 
 		return $info;
diff --git a/includes/upload/UploadFromChunks.php b/includes/upload/UploadFromChunks.php
index 6368db82da..9145a854f3 100644
--- a/includes/upload/UploadFromChunks.php
+++ b/includes/upload/UploadFromChunks.php
@@ -76,18 +76,18 @@ class UploadFromChunks extends UploadFromFile {
 
 		$this->verifyChunk();
 		// Create a local stash target
-		$this->mLocalFile = parent::doStashFile( $user );
+		$this->mStashFile = parent::doStashFile( $user );
 		// Update the initial file offset (based on file size)
-		$this->mOffset = $this->mLocalFile->getSize();
-		$this->mFileKey = $this->mLocalFile->getFileKey();
+		$this->mOffset = $this->mStashFile->getSize();
+		$this->mFileKey = $this->mStashFile->getFileKey();
 
 		// Output a copy of this first to chunk 0 location:
-		$this->outputChunk( $this->mLocalFile->getPath() );
+		$this->outputChunk( $this->mStashFile->getPath() );
 
 		// Update db table to reflect initial "chunk" state
 		$this->updateChunkStatus();
 
-		return $this->mLocalFile;
+		return $this->mStashFile;
 	}
 
 	/**
@@ -158,7 +158,7 @@ class UploadFromChunks extends UploadFromFile {
 			return $status;
 		}
 
-		// Update the mTempPath and mLocalFile
+		// Update the mTempPath and mStashFile
 		// (for FileUpload or normal Stash to take over)
 		$tStart = microtime( true );
 		// This is a re-implementation of UploadBase::tryStashFile(), we can't call it because we
@@ -169,14 +169,14 @@ class UploadFromChunks extends UploadFromFile {
 			return $status;
 		}
 		try {
-			$this->mLocalFile = parent::doStashFile( $this->user );
+			$this->mStashFile = parent::doStashFile( $this->user );
 		} catch ( UploadStashException $e ) {
 			$status->fatal( 'uploadstash-exception', get_class( $e ), $e->getMessage() );
 			return $status;
 		}
 
 		$tAmount = microtime( true ) - $tStart;
-		$this->mLocalFile->setLocalReference( $tmpFile ); // reuse (e.g. for getImageInfo())
+		$this->mStashFile->setLocalReference( $tmpFile ); // reuse (e.g. for getImageInfo())
 		wfDebugLog( 'fileconcatenate', "Stashed combined file ($i chunks) in $tAmount seconds." );
 
 		return $status;
diff --git a/includes/upload/UploadFromStash.php b/includes/upload/UploadFromStash.php
index 50bcbc4260..1fbdb7d86d 100644
--- a/includes/upload/UploadFromStash.php
+++ b/includes/upload/UploadFromStash.php
@@ -143,24 +143,6 @@ class UploadFromStash extends UploadBase {
 		return $this->mFileProps['sha1'];
 	}
 
-	/*
-	 * protected function verifyFile() inherited
-	 */
-
-	/**
-	 * Stash the file.
-	 *
-	 * @param User $user
-	 * @return UploadStashFile
-	 */
-	protected function doStashFile( User $user = null ) {
-		// replace mLocalFile with an instance of UploadStashFile, which adds some methods
-		// that are useful for stashed files.
-		$this->mLocalFile = parent::doStashFile( $user );
-
-		return $this->mLocalFile;
-	}
-
 	/**
 	 * Remove a temporarily kept file stashed by saveTempUploadedFile().
 	 * @return bool Success
diff --git a/languages/Language.php b/languages/Language.php
index d96710a626..8b39d7734a 100644
--- a/languages/Language.php
+++ b/languages/Language.php
@@ -25,11 +25,6 @@
  * @defgroup Language Language
  */
 
-if ( !defined( 'MEDIAWIKI' ) ) {
-	echo "This file is part of MediaWiki, it is not a valid entry point.\n";
-	exit( 1 );
-}
-
 use CLDRPluralRuleParser\Evaluator;
 
 /**
diff --git a/languages/i18n/bn.json b/languages/i18n/bn.json
index 4921d09ca5..aa81ac2b05 100644
--- a/languages/i18n/bn.json
+++ b/languages/i18n/bn.json
@@ -1185,6 +1185,7 @@
 	"right-changetags": "নির্দিষ্ট সংস্করণ এবং দীর্ঘ সম্পাদনাগুলোতে [[Special:Tags|ট্যাগ]] সংযোজন ও অপসারণ করুন",
 	"right-deletechangetags": "ডাটাবেজ থেকে [[Special:Tags|ট্যাগ]] অপসারণ করা",
 	"grant-group-email": "ইমেইল পাঠান",
+	"grant-group-private-information": "আপনার সম্পর্কিত ব্যক্তিগত তথ্যে প্রবেশাধিকার পায়",
 	"grant-group-other": "বিবিধ কার্যকলাপ",
 	"grant-createaccount": "অ্যাকাউন্ট তৈরি করুন",
 	"grant-createeditmovepage": "পাতা তৈরি, সম্পাদনা এবং স্থানান্তর করুন",
@@ -1192,6 +1193,7 @@
 	"grant-editmyoptions": "আপনার ব্যবহারকারী পছন্দসমূহ সম্পাদনা করুন",
 	"grant-editmywatchlist": "আপনার নজরতালিকা সম্পাদনা করুন",
 	"grant-editprotected": "সংরক্ষিত পাতা সম্পাদনা করুন",
+	"grant-privateinfo": "ব্যক্তিগত তথ্যে প্রবেশাধিকার",
 	"grant-sendemail": "অন্য ব্যবহারকারীকে ইমেইল পাঠান",
 	"grant-uploadfile": "নতুন ফাইল আপলোড করুন",
 	"grant-basic": "মৌলিক অধিকার",
diff --git a/languages/i18n/fr.json b/languages/i18n/fr.json
index 13cbfb743c..f145ca9c3a 100644
--- a/languages/i18n/fr.json
+++ b/languages/i18n/fr.json
@@ -1723,7 +1723,7 @@
 	"nolinkstoimage": "Aucune page n'utilise ce fichier.",
 	"morelinkstoimage": "Voir [[Special:WhatLinksHere/$1|plus de liens]] vers ce fichier.",
 	"linkstoimage-redirect": "$1 (redirection de fichier) $2",
-	"duplicatesoffile": "{{PLURAL:$1|Le fichier suivant est un duplicata|Les fichiers suivants sont des duplicatas}} de celui-ci ([[Special:FileDuplicateSearch/$2|plus de détails]]) :",
+	"duplicatesoffile": "{{PLURAL:$1|Le fichier suivant est un doublon|Les $1 fichiers suivants sont des doublons}} de celui-ci ([[Special:FileDuplicateSearch/$2|plus de détails]]) :",
 	"sharedupload": "Ce fichier provient de : $1. Il peut être utilisé par d'autres projets.",
 	"sharedupload-desc-there": "Ce fichier provient de : $1. Il peut être utilisé par d'autres projets.\nVeuillez consulter [$2 sa page de description] pour plus d'informations.",
 	"sharedupload-desc-here": "Ce fichier provient de $1. Il peut être utilisé par d'autres projets.\nSa description sur sa [$2 page de description] est affichée ci-dessous.",
@@ -1751,15 +1751,15 @@
 	"filedelete-intro-old": "Vous êtes en train d'effacer la version de '''[[Media:$1|$1]]''' du [$4 $2 à $3].",
 	"filedelete-comment": "Motif :",
 	"filedelete-submit": "Supprimer",
-	"filedelete-success": "'''$1''' a été supprimé.",
-	"filedelete-success-old": "La version de '''[[Media:$1|$1]]''' du $2 à $3 a été supprimée.",
-	"filedelete-nofile": "'''$1''' n'existe pas.",
-	"filedelete-nofile-old": "Il n'existe aucune version archivée de '''$1''' avec les attributs indiqués.",
+	"filedelete-success": "<strong>$1</strong> a été supprimé.",
+	"filedelete-success-old": "La version de <strong>[[Media:$1|$1]]</strong> du $2 à $3 a été supprimée.",
+	"filedelete-nofile": "<strong>$1</strong> n'existe pas.",
+	"filedelete-nofile-old": "Il n'existe aucune version archivée de <strong>$1</strong> avec les attributs indiqués.",
 	"filedelete-otherreason": "Motif autre / supplémentaire :",
 	"filedelete-reason-otherlist": "Autre motif",
 	"filedelete-reason-dropdown": "* Motifs fréquents de suppression de fichiers\n** Violation du droit d'auteur\n** Fichier dupliqué",
-	"filedelete-edit-reasonlist": "Modifier les motifs fréquents de suppression",
-	"filedelete-maintenance": "La suppression et restauration de fichiers est temporairement désactivée durant la maintenance.",
+	"filedelete-edit-reasonlist": "Modifier les motifs de suppression",
+	"filedelete-maintenance": "La suppression et la restauration de fichiers sont  temporairement désactivées durant la maintenance.",
 	"filedelete-maintenance-title": "Impossible de supprimer le fichier",
 	"mimesearch": "Recherche par type de contenu MIME",
 	"mimesearch-summary": "Cette page vous permet de filtrer les fichiers par leur type de contenu MIME.\nEntrée : type_de_contenu/sous-type ou type_de_contenu/*, par ex. <code>image/jpeg</code>.",
@@ -1777,7 +1777,7 @@
 	"randompage-nopages": "Il n'y a aucune page dans {{PLURAL:$2|l'espace de noms|les espaces de noms}} : $1.",
 	"randomincategory": "Page au hasard dans la catégorie",
 	"randomincategory-invalidcategory": "« $1 » n’est pas un nom de catégorie valide.",
-	"randomincategory-nopages": "Il n’y a pas de page dans [[:Category:$1]].",
+	"randomincategory-nopages": "Il n’y a pas de pages dans la catégorie [[:Category:$1|$1]].",
 	"randomincategory-category": "Catégorie :",
 	"randomincategory-legend": "Page aléatoire dans la catégorie",
 	"randomincategory-submit": "Lancer",
diff --git a/languages/i18n/got.json b/languages/i18n/got.json
index 090585a7cf..bda094adea 100644
--- a/languages/i18n/got.json
+++ b/languages/i18n/got.json
@@ -182,7 +182,7 @@
 	"mainpage-nstab": "𐌰𐌽𐌰𐍃𐍄𐍉𐌳𐌴𐌹𐌽𐌹𐌻𐌰𐌿𐍆𐍃",
 	"error": "𐌰𐌹𐍂𐌶𐌴𐌹",
 	"databaseerror-error": "𐌰𐌹𐍂𐌶𐌴𐌹: $1",
-	"missing-article": "𐍃𐌰 𐌳𐌰𐍄𐌰𐌱𐌿𐍃 𐌽𐌹 𐌲𐌰𐌽𐌰𐌼 𐌸𐌰𐌽𐌰 𐌱𐍉𐌺𐌰𐍅𐌰𐌿𐍂𐌳𐌰𐌽 𐌴𐌹 𐌹𐍄𐌰 𐍃𐌺𐌰𐌻 𐌱𐌹𐌲𐌹𐍄𐌰𐌽: \"$1\" $2\n\n(The data base did not find the text of a page that it should have found, named \"$1\" $2.\n\nThis is usually caused by following an outdated diff or history link to a page that has been deleted.\n\nIf this is not the case, you may have found a bug in the software.\nPlease report this to an [[Special:ListUsers/sysop|administrator]], making note of the URL.)",
+	"missing-article": "𐌳𐌰𐍄𐌰𐌱𐌴𐍃 𐌽𐌹 𐌱𐌹𐌲𐌰𐍄 𐌱𐍉𐌺𐍉𐍃 𐌻𐌰𐌿𐌱𐌹𐍃 𐌸𐌹𐌶𐌴𐌹 𐍃𐌺𐌿𐌻𐌳𐌴𐌳𐌹 𐌱𐌹𐌲𐌹𐍄𐌰𐌽, 𐌷𐌰𐌹𐍄𐌰𐌽𐍃 \"$1\" $2. \n\n𐌸𐌰𐍄𐌰 𐌿𐍆𐍄𐌰 𐍅𐌰𐌹𐍂𐌸𐌹𐌸 𐌾𐌰𐌱𐌰𐌹 𐌻𐌰𐌹𐍃𐍄𐌾𐌰𐌳𐌰 𐍆𐌰𐌹𐍂𐌽𐌾𐌰 𐌳𐌹𐍆𐍆 𐌸𐌰𐌿 𐍃𐍀𐌹𐌻𐌻𐌰𐌲𐌰𐍅𐌹𐍃𐍃 𐍃𐌴𐌹 𐍆𐍂𐌰𐌵𐌹𐍃𐍄𐌹𐌳𐌰 𐌹𐍃𐍄. 𐌽𐌹𐌱𐌰𐌹 𐌹𐍃𐍄, 𐌼𐌰𐌷𐍄𐍃 𐌹𐍃𐍄 𐌴𐌹 𐌱𐌹𐌲𐌴𐍄𐌴𐌹𐍃 𐌰𐌹𐍂𐌶𐌴𐌹𐌽 𐌹𐌽 𐍃𐌰𐌿𐍆𐍄𐍅𐌰𐌹𐍂𐌰. \n\n𐌱𐌹𐌳𐌾𐌰𐌼 𐌸𐌿𐌺, 𐌼𐌴𐍂𐌴𐌹 𐌸𐌰𐍄𐌰 𐌳𐌿 [[Special:ListUsers/sysop\n|𐍂𐌴𐌹𐌺]] 𐌲𐌹𐍆𐌿𐌷 𐌲𐌰𐍅𐌹𐍃𐍃.",
 	"badtitle": "𐌿𐌽𐍂𐌰𐌹𐌷𐍄𐌰𐍄𐌰 𐌿𐍆𐌰𐍂𐌼𐌴𐌻𐌹",
 	"badtitletext": "𐍆𐍂𐌰𐌹𐌷𐌰𐌽𐍃 𐌻𐌰𐌿𐍆𐍃 𐍅𐌰𐍃 𐌿𐌽𐌲𐌰𐌼𐌰𐌲𐌰𐌽𐌳𐍃, 𐌻𐌰𐌿𐍃, 𐌰𐌹𐌸𐌸𐌰𐌿 𐌿𐌽𐍂𐌰𐌹𐌷𐍄𐌰𐌱𐌰 𐌲𐌰𐍅𐌹𐌳𐌰𐌽𐍃 𐌼𐌹𐌸𐍂𐌰𐌶𐌳𐌰 𐌸𐌰𐌿 𐌼𐌹𐌸-𐍅𐌹𐌺𐌹 𐌿𐍆𐌰𐍂𐌼𐌴𐌻𐌹. 𐌼𐌰𐌲𐌹 𐌷𐌰𐌱𐌰𐌽 𐌰𐌹𐌽𐌰 𐌸𐌰𐌿 𐌼𐌰𐌽𐌰𐌲𐌹𐌶𐍉𐍃 𐌱𐍉𐌺𐍉𐍃 𐌱𐍂𐌿𐌺𐌹𐌳𐍉𐍃 𐌹𐌽 𐌿𐍆𐌰𐍂𐌼𐌴𐌻𐌾𐌰𐌼.",
 	"viewsource": "𐍃𐌰𐌹𐍈 𐌱𐍂𐌿𐌽𐌽𐌰𐌽",
diff --git a/languages/i18n/nap.json b/languages/i18n/nap.json
index c756f47e2e..b13f5f9189 100644
--- a/languages/i18n/nap.json
+++ b/languages/i18n/nap.json
@@ -1266,6 +1266,7 @@
 	"action-applychangetags": "appreca tag pe' tramente ca se fanno 'e cagnamiente vuoste",
 	"action-changetags": "azzecca o lèva tag a caso dint'a verziune nnividuale e riggistre 'e log",
 	"action-deletechangetags": "scancellare 'e tag d' 'o database",
+	"action-purge": "agghiuorna sta paggena",
 	"nchanges": "$1 {{PLURAL:$1|cagnamiento|cagnamiente}}",
 	"enhancedrc-since-last-visit": "$1 {{PLURAL:$1|'a ll'urdema visita}}",
 	"enhancedrc-history": "cronologgia",
@@ -1510,6 +1511,7 @@
 	"uploadstash-errclear": "'A pulezzia d' 'e file scassaje.",
 	"uploadstash-refresh": "Agghiuorna l'elenco d' 'e file",
 	"uploadstash-thumbnail": "vide miniatura",
+	"uploadstash-exception": "Nun s'è pututo sarvà 'a càrreca dint' 'a stash ($1): \"$2\".",
 	"invalid-chunk-offset": "Distanza d' 'a parte nun valida",
 	"img-auth-accessdenied": "Acciesso negato",
 	"img-auth-nopathinfo": "PATH_INFO mancante.\n'O server nun è mpustato pe' passà sta nfurmazione.\nPuò darse ca, essenno basato ncopp'a CGI, nun putesse suppurtà img_auth.\nVide https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Image_Authorization",
@@ -1925,9 +1927,11 @@
 	"watchnologin": "Acciesso nun affettuato",
 	"addwatch": "Miette dint' 'a l'elenco 'e paggene cuntrullate",
 	"addedwatchtext": "'A paggena \"[[:$1]]\" e 'a paggena 'e chiacchiera è stata azzeccata dint'a l'elenco 'e [[Special:Watchlist|paggene cuntrullate]].",
+	"addedwatchtext-talk": "\"[[:$1]]\" e 'a paggena 'e chiacchiera suòccia è stata azzeccata dint'a l'elenco 'e [[Special:Watchlist|paggene cuntrullate]] vuosto.",
 	"addedwatchtext-short": "Chista paggena \"$1\" è stata azzeccata a l'elenco 'e paggene cuntrullate.",
 	"removewatch": "Leva 'a l'elenco 'e paggene cuntrullate",
-	"removedwatchtext": "\"[[:$1]]\" 'e 'a paggena 'e chiacchiera soja so' state scancellata 'a l'elenco [[Special:Watchlist|'e paggene cuntrullate]] vuosto.",
+	"removedwatchtext": "\"[[:$1]]\" e 'a paggena 'e chiacchiera soja so' state scancellate 'a l'elenco [[Special:Watchlist|'e paggene cuntrullate]] vuosto.",
+	"removedwatchtext-talk": "\"[[:$1]]\" e 'a paggena 'e chiacchiera soja so' state luvate 'a l'elenco [[Special:Watchlist|'e paggene cuntrullate]] vuosto.",
 	"removedwatchtext-short": "Chista paggena \"$1\" è stata luvata a l'elenco 'e paggene cuntrullate.",
 	"watch": "Secuta",
 	"watchthispage": "Tiene d'uocchio sta paggena",
diff --git a/resources/ResourcesOOUI.php b/resources/ResourcesOOUI.php
index b31fe829f8..c3a287dc8d 100644
--- a/resources/ResourcesOOUI.php
+++ b/resources/ResourcesOOUI.php
@@ -68,6 +68,9 @@ return call_user_func( function () {
 			'es5-shim',
 			'oojs',
 			'oojs-ui-core.styles',
+			'oojs-ui.styles.icons',
+			'oojs-ui.styles.indicators',
+			'oojs-ui.styles.textures',
 			'mediawiki.language',
 		],
 		'targets' => [ 'desktop', 'mobile' ],
@@ -78,14 +81,6 @@ return call_user_func( function () {
 		'styles' => 'resources/src/oojs-ui-local.css', // HACK, see inside the file
 		'skinStyles' => $getSkinSpecific( 'core' ),
 		'targets' => [ 'desktop', 'mobile' ],
-		// ResourceLoaderImageModule doesn't support 'skipFunction', so instead we set this up so that
-		// this module is skipped together with its dependencies. Nothing else depends on these modules.
-		'dependencies' => [
-			'oojs-ui.styles.icons',
-			'oojs-ui.styles.indicators',
-			'oojs-ui.styles.textures',
-		],
-		'skipFunction' => 'resources/src/oojs-ui-styles-skip.js',
 	];
 
 	// Additional widgets and layouts module.
diff --git a/resources/assets/licenses/README b/resources/assets/licenses/README
index 0f5cf513ca..dae2549b14 100644
--- a/resources/assets/licenses/README
+++ b/resources/assets/licenses/README
@@ -1,4 +1,4 @@
 These license icons are used in LocalSettings.php files that are generated by
-the installer. Although public domain has been removed from the installer as
-an option, the image needs to remain here to support installations which refer
-to it in LocalSettings.php.
+the installer. Although "Public domain" has been removed from the installer as
+an option, the public-domain.png image needs to remain here to support older
+installations that refer to it in LocalSettings.php.
diff --git a/resources/src/oojs-ui-styles-skip.js b/resources/src/oojs-ui-styles-skip.js
deleted file mode 100644
index 57c905a345..0000000000
--- a/resources/src/oojs-ui-styles-skip.js
+++ /dev/null
@@ -1,9 +0,0 @@
-/*!
- * Skip function for OOjs UI PHP style modules.
- *
- * The `<meta name="X-OOUI-PHP" />` is added to pages by OutputPage::enableOOUI().
- *
- * Looking for elements in the DOM might be expensive, but it's probably better than double-loading
- * 200 KB of CSS with embedded images because of bug T87871.
- */
-return !!jQuery( 'meta[name="X-OOUI-PHP"]' ).length;
diff --git a/tests/phpunit/includes/auth/AuthenticationRequestTest.php b/tests/phpunit/includes/auth/AuthenticationRequestTest.php
index a7df221700..7d2ba8d749 100644
--- a/tests/phpunit/includes/auth/AuthenticationRequestTest.php
+++ b/tests/phpunit/includes/auth/AuthenticationRequestTest.php
@@ -172,6 +172,7 @@ class AuthenticationRequestTest extends \MediaWikiTestCase {
 				'type' => 'string',
 				'label' => $msg,
 				'help' => $msg,
+				'sensitive' => true,
 			],
 			'string3' => [
 				'type' => 'string',
@@ -206,6 +207,7 @@ class AuthenticationRequestTest extends \MediaWikiTestCase {
 		$expect = $req1->getFieldInfo();
 		foreach ( $expect as $name => &$options ) {
 			$options['optional'] = !empty( $options['optional'] );
+			$options['sensitive'] = !empty( $options['sensitive'] );
 		}
 		unset( $options );
 		$this->assertEquals( $expect, $fields );
@@ -225,8 +227,10 @@ class AuthenticationRequestTest extends \MediaWikiTestCase {
 
 		$fields = AuthenticationRequest::mergeFieldInfo( [ $req1, $req2 ] );
 		$expect += $req2->getFieldInfo();
+		$expect['string1']['sensitive'] = true;
 		$expect['string2']['optional'] = false;
 		$expect['string3']['optional'] = false;
+		$expect['string3']['sensitive'] = false;
 		$expect['select']['options']['bar'] = $msg;
 		$this->assertEquals( $expect, $fields );
 
@@ -237,6 +241,7 @@ class AuthenticationRequestTest extends \MediaWikiTestCase {
 		$fields = AuthenticationRequest::mergeFieldInfo( [ $req1, $req2 ] );
 		$expect += $req2->getFieldInfo();
 		$expect['string1']['optional'] = false;
+		$expect['string1']['sensitive'] = true;
 		$expect['string3']['optional'] = false;
 		$expect['select']['optional'] = false;
 		$expect['select']['options']['bar'] = $msg;
@@ -246,7 +251,11 @@ class AuthenticationRequestTest extends \MediaWikiTestCase {
 
 		$fields = AuthenticationRequest::mergeFieldInfo( [ $req1, $req2 ] );
 		$expect = $req1->getFieldInfo() + $req2->getFieldInfo();
+		foreach ( $expect as $name => &$options ) {
+			$options['sensitive'] = !empty( $options['sensitive'] );
+		}
 		$expect['string1']['optional'] = false;
+		$expect['string1']['sensitive'] = true;
 		$expect['string2']['optional'] = true;
 		$expect['string3']['optional'] = true;
 		$expect['select']['optional'] = false;
diff --git a/tests/phpunit/includes/auth/AuthenticationRequestTestCase.php b/tests/phpunit/includes/auth/AuthenticationRequestTestCase.php
index aa0e3c70f5..b5c8a36cd1 100644
--- a/tests/phpunit/includes/auth/AuthenticationRequestTestCase.php
+++ b/tests/phpunit/includes/auth/AuthenticationRequestTestCase.php
@@ -32,6 +32,13 @@ abstract class AuthenticationRequestTestCase extends \MediaWikiTestCase {
 			if ( isset( $data['image'] ) ) {
 				$this->assertType( 'string', $data['image'], "Field $field, image" );
 			}
+			if ( isset( $data['sensitive'] ) ) {
+				$this->assertType( 'bool', $data['sensitive'], "Field $field, sensitive" );
+			}
+			if ( $data['type'] === 'password' ) {
+				$this->assertTrue( !empty( $data['sensitive'] ),
+					"Field $field, password field must be sensitive" );
+			}
 
 			switch ( $data['type'] ) {
 				case 'string':
diff --git a/tests/phpunit/includes/auth/EmailNotificationSecondaryAuthenticationProviderTest.php b/tests/phpunit/includes/auth/EmailNotificationSecondaryAuthenticationProviderTest.php
index 18c46f7cc5..c52c3e9f54 100644
--- a/tests/phpunit/includes/auth/EmailNotificationSecondaryAuthenticationProviderTest.php
+++ b/tests/phpunit/includes/auth/EmailNotificationSecondaryAuthenticationProviderTest.php
@@ -60,19 +60,25 @@ class EmailNotificationSecondaryAuthenticationProviderTest extends \PHPUnit_Fram
 		$creator = $this->getMock( 'User' );
 		$userWithoutEmail = $this->getMock( 'User' );
 		$userWithoutEmail->expects( $this->any() )->method( 'getEmail' )->willReturn( '' );
+		$userWithoutEmail->expects( $this->any() )->method( 'getInstanceForUpdate' )->willReturnSelf();
 		$userWithoutEmail->expects( $this->never() )->method( 'sendConfirmationMail' );
 		$userWithEmailError = $this->getMock( 'User' );
 		$userWithEmailError->expects( $this->any() )->method( 'getEmail' )->willReturn( 'foo@bar.baz' );
+		$userWithEmailError->expects( $this->any() )->method( 'getInstanceForUpdate' )->willReturnSelf();
 		$userWithEmailError->expects( $this->any() )->method( 'sendConfirmationMail' )
 			->willReturn( \Status::newFatal( 'fail' ) );
 		$userExpectsConfirmation = $this->getMock( 'User' );
 		$userExpectsConfirmation->expects( $this->any() )->method( 'getEmail' )
 			->willReturn( 'foo@bar.baz' );
+		$userExpectsConfirmation->expects( $this->any() )->method( 'getInstanceForUpdate' )
+			->willReturnSelf();
 		$userExpectsConfirmation->expects( $this->once() )->method( 'sendConfirmationMail' )
 			->willReturn( \Status::newGood() );
 		$userNotExpectsConfirmation = $this->getMock( 'User' );
 		$userNotExpectsConfirmation->expects( $this->any() )->method( 'getEmail' )
 			->willReturn( 'foo@bar.baz' );
+		$userNotExpectsConfirmation->expects( $this->any() )->method( 'getInstanceForUpdate' )
+			->willReturnSelf();
 		$userNotExpectsConfirmation->expects( $this->never() )->method( 'sendConfirmationMail' );
 
 		$provider = new EmailNotificationSecondaryAuthenticationProvider( [
diff --git a/tests/phpunit/includes/content/ContentHandlerTest.php b/tests/phpunit/includes/content/ContentHandlerTest.php
index bb9050fbd3..39948ca130 100644
--- a/tests/phpunit/includes/content/ContentHandlerTest.php
+++ b/tests/phpunit/includes/content/ContentHandlerTest.php
@@ -376,8 +376,7 @@ class ContentHandlerTest extends MediaWikiTestCase {
 		$content = new WikitextContent( 'test text' );
 		$ok = ContentHandler::runLegacyHooks(
 			'testRunLegacyHooks',
-			[ 'foo', &$content, 'bar' ],
-			false
+			[ 'foo', &$content, 'bar' ]
 		);
 
 		$this->assertTrue( $ok, "runLegacyHooks should have returned true" );
@@ -415,6 +414,32 @@ class ContentHandlerTest extends MediaWikiTestCase {
 		$this->assertInstanceOf( $handlerClass, $handler );
 	}
 
+	public function testGetFieldsForSearchIndex() {
+		$searchEngine = $this->newSearchEngine();
+
+		$handler = ContentHandler::getForModelID( CONTENT_MODEL_WIKITEXT );
+
+		$fields = $handler->getFieldsForSearchIndex( $searchEngine );
+
+		$this->assertArrayHasKey( 'category', $fields );
+		$this->assertArrayHasKey( 'external_link', $fields );
+		$this->assertArrayHasKey( 'outgoing_link', $fields );
+		$this->assertArrayHasKey( 'template', $fields );
+	}
+
+	private function newSearchEngine() {
+		$searchEngine = $this->getMockBuilder( 'SearchEngine' )
+			->getMock();
+
+		$searchEngine->expects( $this->any() )
+			->method( 'makeSearchFieldMapping' )
+			->will( $this->returnCallback( function( $name, $type ) {
+					return new DummySearchIndexFieldDefinition( $name, $type );
+			} ) );
+
+		return $searchEngine;
+	}
+
 	/**
 	 * @covers ContentHandler::getDataForSearchIndex
 	 */
@@ -425,7 +450,7 @@ class ContentHandlerTest extends MediaWikiTestCase {
 
 		$this->setTemporaryHook( 'SearchDataForIndex',
 			function ( &$fields, ContentHandler $handler, WikiPage $page, ParserOutput $output,
-			           SearchEngine $engine ) {
+					   SearchEngine $engine ) {
 				$fields['testDataField'] = 'test content';
 			} );
 
diff --git a/tests/phpunit/includes/content/WikitextStructureTest.php b/tests/phpunit/includes/content/WikitextStructureTest.php
index 6d83057b7e..4301fb8c35 100644
--- a/tests/phpunit/includes/content/WikitextStructureTest.php
+++ b/tests/phpunit/includes/content/WikitextStructureTest.php
@@ -25,61 +25,6 @@ class WikitextStructureTest extends MediaWikiLangTestCase {
 		return new WikiTextStructure( $this->getParserOutput( $text ) );
 	}
 
-	public function testCategories() {
-		$text = <<<END
-We also have a {{Template}} and an {{Another template}} in addition. 
-This text also has [[Category:Some Category| ]] and then [[Category:Yet another category]].
-And [[Category:Some Category| this category]] is repeated.
-END;
-		$struct = $this->getStructure( $text );
-		$cats = $struct->categories();
-		$this->assertCount( 2, $cats );
-		$this->assertContains( "Some Category", $cats );
-		$this->assertContains( "Yet another category", $cats );
-	}
-
-	public function testOutgoingLinks() {
-		$text = <<<END
-Here I add link to [[Some Page]]. And [[Some Page|This same page]] gets linked twice. 
-We also have [[File:Image.jpg|image]].
-We also have a {{Template}} and an {{Another template}} in addition. 
-Some templates are {{lowercase}}.
-And [[Some_Page]] is linked again. 
-It also has [[Category:Some Category| ]] and then [[Category:Yet another category]].
-Also link to a [[Talk:TestTitle|talk page]] is here. 
-END;
-		$struct = $this->getStructure( $text );
-		$links = $struct->outgoingLinks();
-		$this->assertContains( "Some_Page", $links );
-		$this->assertContains( "Template:Template", $links );
-		$this->assertContains( "Template:Another_template", $links );
-		$this->assertContains( "Template:Lowercase", $links );
-		$this->assertContains( "Talk:TestTitle", $links );
-		$this->assertCount( 5, $links );
-	}
-
-	public function testTemplates() {
-		$text = <<<END
-We have a {{Template}} and an {{Another template}} in addition. 
-Some templates are {{lowercase}}. And this {{Template}} is repeated. 
-Here is {{another_template|with=argument}}.
-This is a template that {{Xdoes not exist}}.
-END;
-		$this->setTemporaryHook( 'TitleExists', function ( Title $title, &$exists ) {
-			$txt = $title->getBaseText();
-			if ( $txt[0] != 'X' ) {
-				$exists = true;
-			}
-			return true;
-		} );
-		$struct = $this->getStructure( $text );
-		$templates = $struct->templates();
-		$this->assertCount( 3, $templates );
-		$this->assertContains( "Template:Template", $templates );
-		$this->assertContains( "Template:Another template", $templates );
-		$this->assertContains( "Template:Lowercase", $templates );
-	}
-
 	public function testHeadings() {
 		$text = <<<END
 Some text here
diff --git a/tests/phpunit/includes/db/DatabaseTest.php b/tests/phpunit/includes/db/DatabaseTest.php
index 723f1c319e..7e55a7327a 100644
--- a/tests/phpunit/includes/db/DatabaseTest.php
+++ b/tests/phpunit/includes/db/DatabaseTest.php
@@ -285,8 +285,42 @@ class DatabaseTest extends MediaWikiTestCase {
 			$called = true;
 			$db->setFlag( DBO_TRX );
 		} );
-		$db->rollback( __METHOD__ );
+		$db->rollback( __METHOD__, IDatabase::FLUSHING_ALL_PEERS );
 		$this->assertFalse( $db->getFlag( DBO_TRX ), 'DBO_TRX restored to default' );
 		$this->assertTrue( $called, 'Callback reached' );
 	}
+
+	public function testGetScopedLock() {
+		$db = $this->db;
+
+		$db->setFlag( DBO_TRX );
+		try {
+			$this->badLockingMethodImplicit( $db );
+		} catch ( RunTimeException $e ) {
+			$this->assertTrue( $db->trxLevel() > 0, "Transaction not committed." );
+		}
+		$db->clearFlag( DBO_TRX );
+		$db->rollback( __METHOD__, IDatabase::FLUSHING_ALL_PEERS );
+		$this->assertTrue( $db->lockIsFree( 'meow', __METHOD__ ) );
+
+		try {
+			$this->badLockingMethodExplicit( $db );
+		} catch ( RunTimeException $e ) {
+			$this->assertTrue( $db->trxLevel() > 0, "Transaction not committed." );
+		}
+		$db->rollback( __METHOD__, IDatabase::FLUSHING_ALL_PEERS );
+		$this->assertTrue( $db->lockIsFree( 'meow', __METHOD__ ) );
+	}
+
+	private function badLockingMethodImplicit( IDatabase $db ) {
+		$lock = $db->getScopedLockAndFlush( 'meow', __METHOD__, 1 );
+		$db->query( "SELECT 1" ); // trigger DBO_TRX
+		throw new RunTimeException( "Uh oh!" );
+	}
+
+	private function badLockingMethodExplicit( IDatabase $db ) {
+		$lock = $db->getScopedLockAndFlush( 'meow', __METHOD__, 1 );
+		$db->begin( __METHOD__ );
+		throw new RunTimeException( "Uh oh!" );
+	}
 }
diff --git a/tests/phpunit/includes/libs/ObjectFactoryTest.php b/tests/phpunit/includes/libs/ObjectFactoryTest.php
index a4871a64c4..f8dda6f8af 100644
--- a/tests/phpunit/includes/libs/ObjectFactoryTest.php
+++ b/tests/phpunit/includes/libs/ObjectFactoryTest.php
@@ -44,6 +44,7 @@ class ObjectFactoryTest extends PHPUnit_Framework_TestCase {
 
 	/**
 	 * @covers ObjectFactory::getObjectFromSpec
+	 * @covers ObjectFactory::expandClosures
 	 */
 	public function testClosureExpansionEnabled() {
 		$obj = ObjectFactory::getObjectFromSpec( [
@@ -80,6 +81,44 @@ class ObjectFactoryTest extends PHPUnit_Framework_TestCase {
 		$this->assertSame( 'unwrapped', $obj->setterArgs[0] );
 	}
 
+	/**
+	 * @covers ObjectFactory::getObjectFromSpec
+	 */
+	public function testGetObjectFromFactory() {
+		$args = [ 'a', 'b' ];
+		$obj = ObjectFactory::getObjectFromSpec( [
+			'factory' => function ( $a, $b ) {
+				return new ObjectFactoryTestFixture( $a, $b );
+			},
+			'args' => $args,
+		] );
+		$this->assertSame( $args, $obj->args );
+	}
+
+	/**
+	 * @covers ObjectFactory::getObjectFromSpec
+	 * @expectedException InvalidArgumentException
+	 */
+	public function testGetObjectFromInvalid() {
+		$args = [ 'a', 'b' ];
+		$obj = ObjectFactory::getObjectFromSpec( [
+			// Missing 'class' or 'factory'
+			'args' => $args,
+		] );
+	}
+
+	/**
+	 * @covers ObjectFactory::getObjectFromSpec
+	 * @dataProvider provideConstructClassInstance
+	 */
+	public function testGetObjectFromClass( $args ) {
+		$obj = ObjectFactory::getObjectFromSpec( [
+			'class' => 'ObjectFactoryTestFixture',
+			'args' => $args,
+		] );
+		$this->assertSame( $args, $obj->args );
+	}
+
 	/**
 	 * @covers ObjectFactory::constructClassInstance
 	 * @dataProvider provideConstructClassInstance
@@ -91,7 +130,7 @@ class ObjectFactoryTest extends PHPUnit_Framework_TestCase {
 		$this->assertSame( $args, $obj->args );
 	}
 
-	public function provideConstructClassInstance() {
+	public static function provideConstructClassInstance() {
 		// These args go to 11. I thought about making 10 one louder, but 11!
 		return [
 			'0 args' => [ [] ],
@@ -110,6 +149,7 @@ class ObjectFactoryTest extends PHPUnit_Framework_TestCase {
 	}
 
 	/**
+	 * @covers ObjectFactory::constructClassInstance
 	 * @expectedException InvalidArgumentException
 	 */
 	public function testNamedArgs() {
diff --git a/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php b/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
index 6a3cd15fcc..35005f5c6a 100644
--- a/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
+++ b/tests/phpunit/includes/libs/objectcache/WANObjectCacheTest.php
@@ -206,8 +206,10 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$value = wfRandomString();
 
 		$calls = 0;
-		$func = function() use ( &$calls, $value ) {
+		$func = function() use ( &$calls, $value, $cache, $key ) {
 			++$calls;
+			// Immediately kill any mutex rather than waiting a second
+			$cache->delete( $cache::MUTEX_KEY_PREFIX . $key );
 			return $value;
 		};
 
@@ -216,7 +218,7 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$this->assertEquals( 1, $calls, 'Value was populated' );
 
 		// Acquire a lock to verify that getWithSetCallback uses lockTSE properly
-		$this->internalCache->lock( $key, 0 );
+		$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
 
 		$checkKeys = [ wfRandomString() ]; // new check keys => force misses
 		$ret = $cache->getWithSetCallback( $key, 30, $func,
@@ -246,9 +248,11 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$value = wfRandomString();
 
 		$calls = 0;
-		$func = function( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value ) {
+		$func = function( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value, $cache, $key ) {
 			++$calls;
 			$setOpts['since'] = microtime( true ) - 10;
+			// Immediately kill any mutex rather than waiting a second
+			$cache->delete( $cache::MUTEX_KEY_PREFIX . $key );
 			return $value;
 		};
 
@@ -261,7 +265,7 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$this->assertEquals( 1, $calls, 'Value was generated' );
 
 		// Acquire a lock to verify that getWithSetCallback uses lockTSE properly
-		$this->internalCache->lock( $key, 0 );
+		$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
 		$ret = $cache->getWithSetCallback( $key, 30, $func, [ 'lockTSE' => 5 ] );
 		$this->assertEquals( $value, $ret );
 		$this->assertEquals( 1, $calls, 'Callback was not used' );
@@ -278,8 +282,10 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$busyValue = wfRandomString();
 
 		$calls = 0;
-		$func = function() use ( &$calls, $value ) {
+		$func = function() use ( &$calls, $value, $cache, $key ) {
 			++$calls;
+			// Immediately kill any mutex rather than waiting a second
+			$cache->delete( $cache::MUTEX_KEY_PREFIX . $key );
 			return $value;
 		};
 
@@ -288,7 +294,7 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$this->assertEquals( 1, $calls, 'Value was populated' );
 
 		// Acquire a lock to verify that getWithSetCallback uses busyValue properly
-		$this->internalCache->lock( $key, 0 );
+		$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
 
 		$checkKeys = [ wfRandomString() ]; // new check keys => force misses
 		$ret = $cache->getWithSetCallback( $key, 30, $func,
@@ -307,13 +313,13 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$this->assertEquals( $busyValue, $ret, 'Callback was not used; used busy value' );
 		$this->assertEquals( 2, $calls, 'Callback was not used; used busy value' );
 
-		$this->internalCache->unlock( $key );
+		$this->internalCache->delete( $cache::MUTEX_KEY_PREFIX . $key );
 		$ret = $cache->getWithSetCallback( $key, 30, $func,
 			[ 'lockTSE' => 30, 'busyValue' => $busyValue, 'checkKeys' => $checkKeys ] );
 		$this->assertEquals( $value, $ret, 'Callback was used; saved interim' );
 		$this->assertEquals( 3, $calls, 'Callback was used; saved interim' );
 
-		$this->internalCache->lock( $key, 0 );
+		$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
 		$ret = $cache->getWithSetCallback( $key, 30, $func,
 			[ 'busyValue' => $busyValue, 'checkKeys' => $checkKeys ] );
 		$this->assertEquals( $value, $ret, 'Callback was not used; used interim' );
@@ -694,4 +700,26 @@ class WANObjectCacheTest extends MediaWikiTestCase {
 		$this->cache->set( $key, $value, 30, $opts );
 		$this->assertEquals( false, $this->cache->get( $key ), "Pending value not written." );
 	}
+
+	public function testMcRouterSupport() {
+		$localBag = $this->getMock( 'EmptyBagOStuff', [ 'set', 'delete' ] );
+		$localBag->expects( $this->never() )->method( 'set' );
+		$localBag->expects( $this->never() )->method( 'delete' );
+		$wanCache = new WANObjectCache( [
+			'cache' => $localBag,
+			'pool' => 'testcache-hash',
+			'relayer' => new EventRelayerNull( [] )
+		] );
+		$valFunc = function () {
+			return 1;
+		};
+
+		// None of these should use broadcasting commands (e.g. SET, DELETE)
+		$wanCache->get( 'x' );
+		$wanCache->get( 'x', $ctl, [ 'check1' ] );
+		$wanCache->getMulti( [ 'x', 'y' ] );
+		$wanCache->getMulti( [ 'x', 'y' ], $ctls, [ 'check2' ] );
+		$wanCache->getWithSetCallback( 'p', 30, $valFunc );
+		$wanCache->getCheckKeyTime( 'zzz' );
+	}
 }
diff --git a/tests/phpunit/includes/search/ParserOutputSearchDataExtractorTest.php b/tests/phpunit/includes/search/ParserOutputSearchDataExtractorTest.php
new file mode 100644
index 0000000000..69d0b76f25
--- /dev/null
+++ b/tests/phpunit/includes/search/ParserOutputSearchDataExtractorTest.php
@@ -0,0 +1,70 @@
+<?php
+
+use MediaWiki\Search\ParserOutputSearchDataExtractor;
+
+/**
+ * @group Search
+ * @covers MediaWiki\Search\ParserOutputSearchDataExtractor
+ */
+class ParserOutputSearchDataExtractorTest extends MediaWikiLangTestCase {
+
+	public function testGetCategories() {
+		$categories = [
+			'Foo_bar' => 'Bar',
+			'New_page' => ''
+		];
+
+		$parserOutput = new ParserOutput( '', [], $categories );
+
+		$searchDataExtractor = new ParserOutputSearchDataExtractor();
+
+		$this->assertEquals(
+			[ 'Foo bar', 'New page' ],
+			$searchDataExtractor->getCategories( $parserOutput )
+		);
+	}
+
+	public function testGetExternalLinks() {
+		$parserOutput = new ParserOutput();
+
+		$parserOutput->addExternalLink( 'https://foo' );
+		$parserOutput->addExternalLink( 'https://bar' );
+
+		$searchDataExtractor = new ParserOutputSearchDataExtractor();
+
+		$this->assertEquals(
+			[ 'https://foo', 'https://bar' ],
+			$searchDataExtractor->getExternalLinks( $parserOutput )
+		);
+	}
+
+	public function testGetOutgoingLinks() {
+		$parserOutput = new ParserOutput();
+
+		$parserOutput->addLink( Title::makeTitle( NS_MAIN, 'Foo_bar' ), 1 );
+		$parserOutput->addLink( Title::makeTitle( NS_HELP, 'Contents' ), 2 );
+
+		$searchDataExtractor = new ParserOutputSearchDataExtractor();
+
+		// this indexes links with db key
+		$this->assertEquals(
+			[ 'Foo_bar', 'Help:Contents' ],
+			$searchDataExtractor->getOutgoingLinks( $parserOutput )
+		);
+	}
+
+	public function testGetTemplates() {
+		$title = Title::makeTitle( NS_TEMPLATE, 'Cite_news' );
+
+		$parserOutput = new ParserOutput();
+		$parserOutput->addTemplate( $title, 10, 100 );
+
+		$searchDataExtractor = new ParserOutputSearchDataExtractor();
+
+		$this->assertEquals(
+			[ 'Template:Cite news' ],
+			$searchDataExtractor->getTemplates( $parserOutput )
+		);
+	}
+
+}
diff --git a/tests/phpunit/specials/SpecialSearchTest.php b/tests/phpunit/specials/SpecialSearchTest.php
new file mode 100644
index 0000000000..20e88f5a5b
--- /dev/null
+++ b/tests/phpunit/specials/SpecialSearchTest.php
@@ -0,0 +1,23 @@
+<?php
+
+class SpecialSearchText extends \PHPUnit_Framework_TestCase {
+	public function testSubPageRedirect() {
+		$ctx = new RequestContext;
+
+		SpecialPageFactory::executePath(
+			Title::newFromText( 'Special:Search/foo_bar' ),
+			$ctx
+		);
+		$url = $ctx->getOutput()->getRedirect();
+		// some older versions of hhvm have a bug that doesn't parse relative
+		// urls with a port, so help it out a little bit.
+		// https://github.com/facebook/hhvm/issues/7136
+		$url = wfExpandUrl( $url, PROTO_CURRENT );
+
+		$parts = parse_url( $url );
+		$this->assertEquals( '/w/index.php', $parts['path'] );
+		parse_str( $parts['query'], $query );
+		$this->assertEquals( 'Special:Search', $query['title'] );
+		$this->assertEquals( 'foo bar', $query['search'] );
+	}
+}
diff --git a/tests/phpunit/structure/ResourcesTest.php b/tests/phpunit/structure/ResourcesTest.php
index 6446416109..86ce53f339 100644
--- a/tests/phpunit/structure/ResourcesTest.php
+++ b/tests/phpunit/structure/ResourcesTest.php
@@ -86,6 +86,25 @@ class ResourcesTest extends MediaWikiTestCase {
 		}
 	}
 
+	/**
+	 * Verify that all specified messages actually exist.
+	 */
+	public function testMissingMessages() {
+		$data = self::getAllModules();
+		$validDeps = array_keys( $data['modules'] );
+		$lang = Language::factory( 'en' );
+
+		/** @var ResourceLoaderModule $module */
+		foreach ( $data['modules'] as $moduleName => $module ) {
+			foreach ( $module->getMessages() as $msgKey ) {
+				$this->assertTrue(
+					wfMessage( $msgKey )->useDatabase( false )->inLanguage( $lang )->exists(),
+					"Message '$msgKey' required by '$moduleName' must exist"
+				);
+			}
+		}
+	}
+
 	/**
 	 * Verify that all dependencies of all modules are always satisfiable with the 'targets' defined
 	 * for the involved modules.
diff --git a/tests/qunit/QUnitTestResources.php b/tests/qunit/QUnitTestResources.php
index 95f28c85b9..e30088dbc8 100644
--- a/tests/qunit/QUnitTestResources.php
+++ b/tests/qunit/QUnitTestResources.php
@@ -74,6 +74,7 @@ return [
 			'tests/qunit/suites/resources/mediawiki/mediawiki.template.test.js',
 			'tests/qunit/suites/resources/mediawiki/mediawiki.template.mustache.test.js',
 			'tests/qunit/suites/resources/mediawiki/mediawiki.test.js',
+			'tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js',
 			'tests/qunit/suites/resources/mediawiki/mediawiki.html.test.js',
 			'tests/qunit/suites/resources/mediawiki/mediawiki.Title.test.js',
 			'tests/qunit/suites/resources/mediawiki/mediawiki.toc.test.js',
diff --git a/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js b/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js
new file mode 100644
index 0000000000..41d800a0a7
--- /dev/null
+++ b/tests/qunit/suites/resources/mediawiki/mediawiki.loader.test.js
@@ -0,0 +1,685 @@
+( function ( mw, $ ) {
+	QUnit.module( 'mediawiki (mw.loader)' );
+
+	mw.loader.addSource(
+		'testloader',
+		QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/load.mock.php' )
+	);
+
+	/**
+	 * The sync style load test (for @import). This is, in a way, also an open bug for
+	 * ResourceLoader ("execute js after styles are loaded"), but browsers don't offer a
+	 * way to get a callback from when a stylesheet is loaded (that is, including any
+	 * `@import` rules inside). To work around this, we'll have a little time loop to check
+	 * if the styles apply.
+	 *
+	 * Note: This test originally used new Image() and onerror to get a callback
+	 * when the url is loaded, but that is fragile since it doesn't monitor the
+	 * same request as the css @import, and Safari 4 has issues with
+	 * onerror/onload not being fired at all in weird cases like this.
+	 */
+	function assertStyleAsync( assert, $element, prop, val, fn ) {
+		var styleTestStart,
+			el = $element.get( 0 ),
+			styleTestTimeout = ( QUnit.config.testTimeout || 5000 ) - 200;
+
+		function isCssImportApplied() {
+			// Trigger reflow, repaint, redraw, whatever (cross-browser)
+			var x = $element.css( 'height' );
+			x = el.innerHTML;
+			el.className = el.className;
+			x = document.documentElement.clientHeight;
+
+			return $element.css( prop ) === val;
+		}
+
+		function styleTestLoop() {
+			var styleTestSince = new Date().getTime() - styleTestStart;
+			// If it is passing or if we timed out, run the real test and stop the loop
+			if ( isCssImportApplied() || styleTestSince > styleTestTimeout ) {
+				assert.equal( $element.css( prop ), val,
+					'style "' + prop + ': ' + val + '" from url is applied (after ' + styleTestSince + 'ms)'
+				);
+
+				if ( fn ) {
+					fn();
+				}
+
+				return;
+			}
+			// Otherwise, keep polling
+			setTimeout( styleTestLoop );
+		}
+
+		// Start the loop
+		styleTestStart = new Date().getTime();
+		styleTestLoop();
+	}
+
+	function urlStyleTest( selector, prop, val ) {
+		return QUnit.fixurl(
+			mw.config.get( 'wgScriptPath' ) +
+				'/tests/qunit/data/styleTest.css.php?' +
+				$.param( {
+					selector: selector,
+					prop: prop,
+					val: val
+				} )
+		);
+	}
+
+	QUnit.test( 'Basic', 2, function ( assert ) {
+		var isAwesomeDone;
+
+		mw.loader.testCallback = function () {
+			assert.strictEqual( isAwesomeDone, undefined, 'Implementing module is.awesome: isAwesomeDone should still be undefined' );
+			isAwesomeDone = true;
+		};
+
+		mw.loader.implement( 'test.callback', [ QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/callMwLoaderTestCallback.js' ) ] );
+
+		return mw.loader.using( 'test.callback', function () {
+			assert.strictEqual( isAwesomeDone, true, 'test.callback module should\'ve caused isAwesomeDone to be true' );
+			delete mw.loader.testCallback;
+
+		}, function () {
+			assert.ok( false, 'Error callback fired while loader.using "test.callback" module' );
+		} );
+	} );
+
+	QUnit.test( 'Object method as module name', 2, function ( assert ) {
+		var isAwesomeDone;
+
+		mw.loader.testCallback = function () {
+			assert.strictEqual( isAwesomeDone, undefined, 'Implementing module hasOwnProperty: isAwesomeDone should still be undefined' );
+			isAwesomeDone = true;
+		};
+
+		mw.loader.implement( 'hasOwnProperty', [ QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/callMwLoaderTestCallback.js' ) ], {}, {} );
+
+		return mw.loader.using( 'hasOwnProperty', function () {
+			assert.strictEqual( isAwesomeDone, true, 'hasOwnProperty module should\'ve caused isAwesomeDone to be true' );
+			delete mw.loader.testCallback;
+
+		}, function () {
+			assert.ok( false, 'Error callback fired while loader.using "hasOwnProperty" module' );
+		} );
+	} );
+
+	QUnit.test( '.using( .. ) Promise', 2, function ( assert ) {
+		var isAwesomeDone;
+
+		mw.loader.testCallback = function () {
+			assert.strictEqual( isAwesomeDone, undefined, 'Implementing module is.awesome: isAwesomeDone should still be undefined' );
+			isAwesomeDone = true;
+		};
+
+		mw.loader.implement( 'test.promise', [ QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/callMwLoaderTestCallback.js' ) ] );
+
+		return mw.loader.using( 'test.promise' )
+		.done( function () {
+			assert.strictEqual( isAwesomeDone, true, 'test.promise module should\'ve caused isAwesomeDone to be true' );
+			delete mw.loader.testCallback;
+
+		} )
+		.fail( function () {
+			assert.ok( false, 'Error callback fired while loader.using "test.promise" module' );
+		} );
+	} );
+
+	QUnit.test( '.implement( styles={ "css": [text, ..] } )', 2, function ( assert ) {
+		var $element = $( '<div class="mw-test-implement-a"></div>' ).appendTo( '#qunit-fixture' );
+
+		assert.notEqual(
+			$element.css( 'float' ),
+			'right',
+			'style is clear'
+		);
+
+		mw.loader.implement(
+			'test.implement.a',
+			function () {
+				assert.equal(
+					$element.css( 'float' ),
+					'right',
+					'style is applied'
+				);
+			},
+			{
+				all: '.mw-test-implement-a { float: right; }'
+			}
+		);
+
+		return mw.loader.using( 'test.implement.a' );
+	} );
+
+	QUnit.test( '.implement( styles={ "url": { <media>: [url, ..] } } )', 7, function ( assert ) {
+		var $element1 = $( '<div class="mw-test-implement-b1"></div>' ).appendTo( '#qunit-fixture' ),
+			$element2 = $( '<div class="mw-test-implement-b2"></div>' ).appendTo( '#qunit-fixture' ),
+			$element3 = $( '<div class="mw-test-implement-b3"></div>' ).appendTo( '#qunit-fixture' ),
+			done = assert.async();
+
+		assert.notEqual(
+			$element1.css( 'text-align' ),
+			'center',
+			'style is clear'
+		);
+		assert.notEqual(
+			$element2.css( 'float' ),
+			'left',
+			'style is clear'
+		);
+		assert.notEqual(
+			$element3.css( 'text-align' ),
+			'right',
+			'style is clear'
+		);
+
+		mw.loader.implement(
+			'test.implement.b',
+			function () {
+				// Note: done() must only be called when the entire test is
+				// complete. So, make sure that we don't start until *both*
+				// assertStyleAsync calls have completed.
+				var pending = 2;
+				assertStyleAsync( assert, $element2, 'float', 'left', function () {
+					assert.notEqual( $element1.css( 'text-align' ), 'center', 'print style is not applied' );
+
+					pending--;
+					if ( pending === 0 ) {
+						done();
+					}
+				} );
+				assertStyleAsync( assert, $element3, 'float', 'right', function () {
+					assert.notEqual( $element1.css( 'text-align' ), 'center', 'print style is not applied' );
+
+					pending--;
+					if ( pending === 0 ) {
+						done();
+					}
+				} );
+			},
+			{
+				url: {
+					print: [ urlStyleTest( '.mw-test-implement-b1', 'text-align', 'center' ) ],
+					screen: [
+						// bug 40834: Make sure it actually works with more than 1 stylesheet reference
+						urlStyleTest( '.mw-test-implement-b2', 'float', 'left' ),
+						urlStyleTest( '.mw-test-implement-b3', 'float', 'right' )
+					]
+				}
+			}
+		);
+
+		mw.loader.load( 'test.implement.b' );
+	} );
+
+	// Backwards compatibility
+	QUnit.test( '.implement( styles={ <media>: text } ) (back-compat)', 2, function ( assert ) {
+		var $element = $( '<div class="mw-test-implement-c"></div>' ).appendTo( '#qunit-fixture' );
+
+		assert.notEqual(
+			$element.css( 'float' ),
+			'right',
+			'style is clear'
+		);
+
+		mw.loader.implement(
+			'test.implement.c',
+			function () {
+				assert.equal(
+					$element.css( 'float' ),
+					'right',
+					'style is applied'
+				);
+			},
+			{
+				all: '.mw-test-implement-c { float: right; }'
+			}
+		);
+
+		return mw.loader.using( 'test.implement.c' );
+	} );
+
+	// Backwards compatibility
+	QUnit.test( '.implement( styles={ <media>: [url, ..] } ) (back-compat)', 4, function ( assert ) {
+		var $element = $( '<div class="mw-test-implement-d"></div>' ).appendTo( '#qunit-fixture' ),
+			$element2 = $( '<div class="mw-test-implement-d2"></div>' ).appendTo( '#qunit-fixture' ),
+			done = assert.async();
+
+		assert.notEqual(
+			$element.css( 'float' ),
+			'right',
+			'style is clear'
+		);
+		assert.notEqual(
+			$element2.css( 'text-align' ),
+			'center',
+			'style is clear'
+		);
+
+		mw.loader.implement(
+			'test.implement.d',
+			function () {
+				assertStyleAsync( assert, $element, 'float', 'right', function () {
+					assert.notEqual( $element2.css( 'text-align' ), 'center', 'print style is not applied (bug 40500)' );
+					done();
+				} );
+			},
+			{
+				all: [ urlStyleTest( '.mw-test-implement-d', 'float', 'right' ) ],
+				print: [ urlStyleTest( '.mw-test-implement-d2', 'text-align', 'center' ) ]
+			}
+		);
+
+		mw.loader.load( 'test.implement.d' );
+	} );
+
+	// @import (bug 31676)
+	QUnit.test( '.implement( styles has @import )', 7, function ( assert ) {
+		var isJsExecuted, $element,
+			done = assert.async();
+
+		mw.loader.implement(
+			'test.implement.import',
+			function () {
+				assert.strictEqual( isJsExecuted, undefined, 'script not executed multiple times' );
+				isJsExecuted = true;
+
+				assert.equal( mw.loader.getState( 'test.implement.import' ), 'executing', 'module state during implement() script execution' );
+
+				$element = $( '<div class="mw-test-implement-import">Foo bar</div>' ).appendTo( '#qunit-fixture' );
+
+				assert.equal( mw.msg( 'test-foobar' ), 'Hello Foobar, $1!', 'messages load before script execution' );
+
+				assertStyleAsync( assert, $element, 'float', 'right', function () {
+					assert.equal( $element.css( 'text-align' ), 'center',
+						'CSS styles after the @import rule are working'
+					);
+
+					done();
+				} );
+			},
+			{
+				css: [
+					'@import url(\''
+						+ urlStyleTest( '.mw-test-implement-import', 'float', 'right' )
+						+ '\');\n'
+						+ '.mw-test-implement-import { text-align: center; }'
+				]
+			},
+			{
+				'test-foobar': 'Hello Foobar, $1!'
+			}
+		);
+
+		mw.loader.using( 'test.implement.import' ).always( function () {
+			assert.strictEqual( isJsExecuted, true, 'script executed' );
+			assert.equal( mw.loader.getState( 'test.implement.import' ), 'ready', 'module state after script execution' );
+		} );
+	} );
+
+	QUnit.test( '.implement( dependency with styles )', 4, function ( assert ) {
+		var $element = $( '<div class="mw-test-implement-e"></div>' ).appendTo( '#qunit-fixture' ),
+			$element2 = $( '<div class="mw-test-implement-e2"></div>' ).appendTo( '#qunit-fixture' );
+
+		assert.notEqual(
+			$element.css( 'float' ),
+			'right',
+			'style is clear'
+		);
+		assert.notEqual(
+			$element2.css( 'float' ),
+			'left',
+			'style is clear'
+		);
+
+		mw.loader.register( [
+			[ 'test.implement.e', '0', [ 'test.implement.e2' ] ],
+			[ 'test.implement.e2', '0' ]
+		] );
+
+		mw.loader.implement(
+			'test.implement.e',
+			function () {
+				assert.equal(
+					$element.css( 'float' ),
+					'right',
+					'Depending module\'s style is applied'
+				);
+			},
+			{
+				all: '.mw-test-implement-e { float: right; }'
+			}
+		);
+
+		mw.loader.implement(
+			'test.implement.e2',
+			function () {
+				assert.equal(
+					$element2.css( 'float' ),
+					'left',
+					'Dependency\'s style is applied'
+				);
+			},
+			{
+				all: '.mw-test-implement-e2 { float: left; }'
+			}
+		);
+
+		return mw.loader.using( 'test.implement.e' );
+	} );
+
+	QUnit.test( '.implement( only scripts )', 1, function ( assert ) {
+		mw.loader.implement( 'test.onlyscripts', function () {} );
+		assert.strictEqual( mw.loader.getState( 'test.onlyscripts' ), 'ready' );
+	} );
+
+	QUnit.test( '.implement( only messages )', 2, function ( assert ) {
+		assert.assertFalse( mw.messages.exists( 'bug_29107' ), 'Verify that the test message doesn\'t exist yet' );
+
+		// jscs: disable requireCamelCaseOrUpperCaseIdentifiers
+		mw.loader.implement( 'test.implement.msgs', [], {}, { bug_29107: 'loaded' } );
+		// jscs: enable requireCamelCaseOrUpperCaseIdentifiers
+
+		return mw.loader.using( 'test.implement.msgs', function () {
+			assert.ok( mw.messages.exists( 'bug_29107' ), 'Bug 29107: messages-only module should implement ok' );
+		}, function () {
+			assert.ok( false, 'Error callback fired while implementing "test.implement.msgs" module' );
+		} );
+	} );
+
+	QUnit.test( '.implement( empty )', 1, function ( assert ) {
+		mw.loader.implement( 'test.empty' );
+		assert.strictEqual( mw.loader.getState( 'test.empty' ), 'ready' );
+	} );
+
+	QUnit.test( 'Broken indirect dependency', 4, function ( assert ) {
+		// don't emit an error event
+		this.sandbox.stub( mw, 'track' );
+
+		mw.loader.register( [
+			[ 'test.module1', '0' ],
+			[ 'test.module2', '0', [ 'test.module1' ] ],
+			[ 'test.module3', '0', [ 'test.module2' ] ]
+		] );
+		mw.loader.implement( 'test.module1', function () {
+			throw new Error( 'expected' );
+		}, {}, {} );
+		assert.strictEqual( mw.loader.getState( 'test.module1' ), 'error', 'Expected "error" state for test.module1' );
+		assert.strictEqual( mw.loader.getState( 'test.module2' ), 'error', 'Expected "error" state for test.module2' );
+		assert.strictEqual( mw.loader.getState( 'test.module3' ), 'error', 'Expected "error" state for test.module3' );
+
+		assert.strictEqual( mw.track.callCount, 1 );
+	} );
+
+	QUnit.test( 'Circular dependency', 1, function ( assert ) {
+		mw.loader.register( [
+			[ 'test.circle1', '0', [ 'test.circle2' ] ],
+			[ 'test.circle2', '0', [ 'test.circle3' ] ],
+			[ 'test.circle3', '0', [ 'test.circle1' ] ]
+		] );
+		assert.throws( function () {
+			mw.loader.using( 'test.circle3' );
+		}, /Circular/, 'Detect circular dependency' );
+	} );
+
+	QUnit.test( 'Out-of-order implementation', 9, function ( assert ) {
+		mw.loader.register( [
+			[ 'test.module4', '0' ],
+			[ 'test.module5', '0', [ 'test.module4' ] ],
+			[ 'test.module6', '0', [ 'test.module5' ] ]
+		] );
+		mw.loader.implement( 'test.module4', function () {} );
+		assert.strictEqual( mw.loader.getState( 'test.module4' ), 'ready', 'Expected "ready" state for test.module4' );
+		assert.strictEqual( mw.loader.getState( 'test.module5' ), 'registered', 'Expected "registered" state for test.module5' );
+		assert.strictEqual( mw.loader.getState( 'test.module6' ), 'registered', 'Expected "registered" state for test.module6' );
+		mw.loader.implement( 'test.module6', function () {} );
+		assert.strictEqual( mw.loader.getState( 'test.module4' ), 'ready', 'Expected "ready" state for test.module4' );
+		assert.strictEqual( mw.loader.getState( 'test.module5' ), 'registered', 'Expected "registered" state for test.module5' );
+		assert.strictEqual( mw.loader.getState( 'test.module6' ), 'loaded', 'Expected "loaded" state for test.module6' );
+		mw.loader.implement( 'test.module5', function () {} );
+		assert.strictEqual( mw.loader.getState( 'test.module4' ), 'ready', 'Expected "ready" state for test.module4' );
+		assert.strictEqual( mw.loader.getState( 'test.module5' ), 'ready', 'Expected "ready" state for test.module5' );
+		assert.strictEqual( mw.loader.getState( 'test.module6' ), 'ready', 'Expected "ready" state for test.module6' );
+	} );
+
+	QUnit.test( 'Missing dependency', 13, function ( assert ) {
+		mw.loader.register( [
+			[ 'test.module7', '0' ],
+			[ 'test.module8', '0', [ 'test.module7' ] ],
+			[ 'test.module9', '0', [ 'test.module8' ] ]
+		] );
+		mw.loader.implement( 'test.module8', function () {} );
+		assert.strictEqual( mw.loader.getState( 'test.module7' ), 'registered', 'Expected "registered" state for test.module7' );
+		assert.strictEqual( mw.loader.getState( 'test.module8' ), 'loaded', 'Expected "loaded" state for test.module8' );
+		assert.strictEqual( mw.loader.getState( 'test.module9' ), 'registered', 'Expected "registered" state for test.module9' );
+		mw.loader.state( 'test.module7', 'missing' );
+		assert.strictEqual( mw.loader.getState( 'test.module7' ), 'missing', 'Expected "missing" state for test.module7' );
+		assert.strictEqual( mw.loader.getState( 'test.module8' ), 'error', 'Expected "error" state for test.module8' );
+		assert.strictEqual( mw.loader.getState( 'test.module9' ), 'error', 'Expected "error" state for test.module9' );
+		mw.loader.implement( 'test.module9', function () {} );
+		assert.strictEqual( mw.loader.getState( 'test.module7' ), 'missing', 'Expected "missing" state for test.module7' );
+		assert.strictEqual( mw.loader.getState( 'test.module8' ), 'error', 'Expected "error" state for test.module8' );
+		assert.strictEqual( mw.loader.getState( 'test.module9' ), 'error', 'Expected "error" state for test.module9' );
+		mw.loader.using(
+			[ 'test.module7' ],
+			function () {
+				assert.ok( false, 'Success fired despite missing dependency' );
+				assert.ok( true, 'QUnit expected() count dummy' );
+			},
+			function ( e, dependencies ) {
+				assert.strictEqual( $.isArray( dependencies ), true, 'Expected array of dependencies' );
+				assert.deepEqual( dependencies, [ 'test.module7' ], 'Error callback called with module test.module7' );
+			}
+		);
+		mw.loader.using(
+			[ 'test.module9' ],
+			function () {
+				assert.ok( false, 'Success fired despite missing dependency' );
+				assert.ok( true, 'QUnit expected() count dummy' );
+			},
+			function ( e, dependencies ) {
+				assert.strictEqual( $.isArray( dependencies ), true, 'Expected array of dependencies' );
+				dependencies.sort();
+				assert.deepEqual(
+					dependencies,
+					[ 'test.module7', 'test.module8', 'test.module9' ],
+					'Error callback called with all three modules as dependencies'
+				);
+			}
+		);
+	} );
+
+	QUnit.test( 'Dependency handling', 5, function ( assert ) {
+		var done = assert.async();
+		mw.loader.register( [
+			// [module, version, dependencies, group, source]
+			[ 'testMissing', '1', [], null, 'testloader' ],
+			[ 'testUsesMissing', '1', [ 'testMissing' ], null, 'testloader' ],
+			[ 'testUsesNestedMissing', '1', [ 'testUsesMissing' ], null, 'testloader' ]
+		] );
+
+		function verifyModuleStates() {
+			assert.equal( mw.loader.getState( 'testMissing' ), 'missing', 'Module not known to server must have state "missing"' );
+			assert.equal( mw.loader.getState( 'testUsesMissing' ), 'error', 'Module with missing dependency must have state "error"' );
+			assert.equal( mw.loader.getState( 'testUsesNestedMissing' ), 'error', 'Module with indirect missing dependency must have state "error"' );
+		}
+
+		mw.loader.using( [ 'testUsesNestedMissing' ],
+			function () {
+				assert.ok( false, 'Error handler should be invoked.' );
+				assert.ok( true ); // Dummy to reach QUnit expect()
+
+				verifyModuleStates();
+
+				done();
+			},
+			function ( e, badmodules ) {
+				assert.ok( true, 'Error handler should be invoked.' );
+				// As soon as server spits out state('testMissing', 'missing');
+				// it will bubble up and trigger the error callback.
+				// Therefor the badmodules array is not testUsesMissing or testUsesNestedMissing.
+				assert.deepEqual( badmodules, [ 'testMissing' ], 'Bad modules as expected.' );
+
+				verifyModuleStates();
+
+				done();
+			}
+		);
+	} );
+
+	QUnit.test( 'Skip-function handling', 5, function ( assert ) {
+		mw.loader.register( [
+			// [module, version, dependencies, group, source, skip]
+			[ 'testSkipped', '1', [], null, 'testloader', 'return true;' ],
+			[ 'testNotSkipped', '1', [], null, 'testloader', 'return false;' ],
+			[ 'testUsesSkippable', '1', [ 'testSkipped', 'testNotSkipped' ], null, 'testloader' ]
+		] );
+
+		function verifyModuleStates() {
+			assert.equal( mw.loader.getState( 'testSkipped' ), 'ready', 'Module is ready when skipped' );
+			assert.equal( mw.loader.getState( 'testNotSkipped' ), 'ready', 'Module is ready when not skipped but loaded' );
+			assert.equal( mw.loader.getState( 'testUsesSkippable' ), 'ready', 'Module is ready when skippable dependencies are ready' );
+		}
+
+		return mw.loader.using( [ 'testUsesSkippable' ],
+			function () {
+				assert.ok( true, 'Success handler should be invoked.' );
+				assert.ok( true ); // Dummy to match error handler and reach QUnit expect()
+
+				verifyModuleStates();
+			},
+			function ( e, badmodules ) {
+				assert.ok( false, 'Error handler should not be invoked.' );
+				assert.deepEqual( badmodules, [], 'Bad modules as expected.' );
+
+				verifyModuleStates();
+			}
+		);
+	} );
+
+	QUnit.asyncTest( '.load( "//protocol-relative" ) - T32825', 2, function ( assert ) {
+		// This bug was actually already fixed in 1.18 and later when discovered in 1.17.
+		// Test is for regressions!
+
+		// Forge a URL to the test callback script
+		var target = QUnit.fixurl(
+			mw.config.get( 'wgServer' ) + mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/qunitOkCall.js'
+		);
+
+		// Confirm that mw.loader.load() works with protocol-relative URLs
+		target = target.replace( /https?:/, '' );
+
+		assert.equal( target.slice( 0, 2 ), '//',
+			'URL must be relative to test relative URLs!'
+		);
+
+		// Async!
+		// The target calls QUnit.start
+		mw.loader.load( target );
+	} );
+
+	QUnit.asyncTest( '.load( "/absolute-path" )', 2, function ( assert ) {
+		// Forge a URL to the test callback script
+		var target = QUnit.fixurl(
+			mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/qunitOkCall.js'
+		);
+
+		// Confirm that mw.loader.load() works with absolute-paths (relative to current hostname)
+		assert.equal( target.slice( 0, 1 ), '/', 'URL is relative to document root' );
+
+		// Async!
+		// The target calls QUnit.start
+		mw.loader.load( target );
+	} );
+
+	QUnit.test( 'Executing race - T112232', 2, function ( assert ) {
+		var done = false;
+
+		// The red herring schedules its CSS buffer first. In T112232, a bug in the
+		// state machine would cause the job for testRaceLoadMe to run with an earlier job.
+		mw.loader.implement(
+			'testRaceRedHerring',
+			function () {},
+			{ css: [ '.mw-testRaceRedHerring {}' ] }
+		);
+		mw.loader.implement(
+			'testRaceLoadMe',
+			function () {
+				done = true;
+			},
+			{ css: [ '.mw-testRaceLoadMe { float: left; }' ] }
+		);
+
+		mw.loader.load( [ 'testRaceRedHerring', 'testRaceLoadMe' ] );
+		return mw.loader.using( 'testRaceLoadMe', function () {
+			assert.strictEqual( done, true, 'script ran' );
+			assert.strictEqual( mw.loader.getState( 'testRaceLoadMe' ), 'ready', 'state' );
+		} );
+	} );
+
+	QUnit.test( 'require()', 6, function ( assert ) {
+		mw.loader.register( [
+			[ 'test.require1', '0' ],
+			[ 'test.require2', '0' ],
+			[ 'test.require3', '0' ],
+			[ 'test.require4', '0', [ 'test.require3' ] ]
+		] );
+		mw.loader.implement( 'test.require1', function () {} );
+		mw.loader.implement( 'test.require2', function ( $, jQuery, require, module ) {
+			module.exports = 1;
+		} );
+		mw.loader.implement( 'test.require3', function ( $, jQuery, require, module ) {
+			module.exports = function () {
+				return 'hello world';
+			};
+		} );
+		mw.loader.implement( 'test.require4', function ( $, jQuery, require, module ) {
+			var other = require( 'test.require3' );
+			module.exports = {
+				pizza: function () {
+					return other();
+				}
+			};
+		} );
+		return mw.loader.using( [ 'test.require1', 'test.require2', 'test.require3', 'test.require4' ] )
+		.then( function ( require ) {
+			var module1, module2, module3, module4;
+
+			module1 = require( 'test.require1' );
+			module2 = require( 'test.require2' );
+			module3 = require( 'test.require3' );
+			module4 = require( 'test.require4' );
+
+			assert.strictEqual( typeof module1, 'object', 'export of module with no export' );
+			assert.strictEqual( module2, 1, 'export a number' );
+			assert.strictEqual( module3(), 'hello world', 'export a function' );
+			assert.strictEqual( typeof module4.pizza, 'function', 'export an object' );
+			assert.strictEqual( module4.pizza(), 'hello world', 'module can require other modules' );
+
+			assert.throws( function () {
+				require( '_badmodule' );
+			}, /is not loaded/, 'Requesting non-existent modules throws error.' );
+		} );
+	} );
+
+	QUnit.test( 'require() in debug mode', 1, function ( assert ) {
+		var path = mw.config.get( 'wgScriptPath' );
+		mw.loader.register( [
+			[ 'test.require.define', '0' ],
+			[ 'test.require.callback', '0', [ 'test.require.define' ] ]
+		] );
+		mw.loader.implement( 'test.require.callback', [ QUnit.fixurl( path + '/tests/qunit/data/requireCallMwLoaderTestCallback.js' ) ] );
+		mw.loader.implement( 'test.require.define', [ QUnit.fixurl( path + '/tests/qunit/data/defineCallMwLoaderTestCallback.js' ) ] );
+
+		return mw.loader.using( 'test.require.callback' ).then( function ( require ) {
+			var exported = require( 'test.require.callback' );
+			assert.strictEqual( exported, 'Require worked.Define worked.',
+				'module.exports worked in debug mode' );
+		}, function () {
+			assert.ok( false, 'Error callback fired while loader.using "test.require.callback" module' );
+		} );
+	} );
+
+}( mediaWiki, jQuery ) );
diff --git a/tests/qunit/suites/resources/mediawiki/mediawiki.test.js b/tests/qunit/suites/resources/mediawiki/mediawiki.test.js
index baec37c9e2..ab463a9720 100644
--- a/tests/qunit/suites/resources/mediawiki/mediawiki.test.js
+++ b/tests/qunit/suites/resources/mediawiki/mediawiki.test.js
@@ -1,5 +1,5 @@
 /*jshint -W024 */
-( function ( mw, $ ) {
+( function ( mw ) {
 	var specialCharactersPageName,
 		// Can't mock SITENAME since jqueryMsg caches it at load
 		siteName = mw.config.get( 'wgSiteName' );
@@ -32,11 +32,6 @@
 		}
 	} ) );
 
-	mw.loader.addSource(
-		'testloader',
-		QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/load.mock.php' )
-	);
-
 	QUnit.test( 'Initial check', 8, function ( assert ) {
 		assert.ok( window.jQuery, 'jQuery defined' );
 		assert.ok( window.$, '$ defined' );
@@ -349,619 +344,6 @@
 		assert.equal( mw.msg( 'int-msg' ), 'Some Other Message', 'int is resolved' );
 	} );
 
-	/**
-	 * The sync style load test (for @import). This is, in a way, also an open bug for
-	 * ResourceLoader ("execute js after styles are loaded"), but browsers don't offer a
-	 * way to get a callback from when a stylesheet is loaded (that is, including any
-	 * `@import` rules inside). To work around this, we'll have a little time loop to check
-	 * if the styles apply.
-	 *
-	 * Note: This test originally used new Image() and onerror to get a callback
-	 * when the url is loaded, but that is fragile since it doesn't monitor the
-	 * same request as the css @import, and Safari 4 has issues with
-	 * onerror/onload not being fired at all in weird cases like this.
-	 */
-	function assertStyleAsync( assert, $element, prop, val, fn ) {
-		var styleTestStart,
-			el = $element.get( 0 ),
-			styleTestTimeout = ( QUnit.config.testTimeout || 5000 ) - 200;
-
-		function isCssImportApplied() {
-			// Trigger reflow, repaint, redraw, whatever (cross-browser)
-			var x = $element.css( 'height' );
-			x = el.innerHTML;
-			el.className = el.className;
-			x = document.documentElement.clientHeight;
-
-			return $element.css( prop ) === val;
-		}
-
-		function styleTestLoop() {
-			var styleTestSince = new Date().getTime() - styleTestStart;
-			// If it is passing or if we timed out, run the real test and stop the loop
-			if ( isCssImportApplied() || styleTestSince > styleTestTimeout ) {
-				assert.equal( $element.css( prop ), val,
-					'style "' + prop + ': ' + val + '" from url is applied (after ' + styleTestSince + 'ms)'
-				);
-
-				if ( fn ) {
-					fn();
-				}
-
-				return;
-			}
-			// Otherwise, keep polling
-			setTimeout( styleTestLoop );
-		}
-
-		// Start the loop
-		styleTestStart = new Date().getTime();
-		styleTestLoop();
-	}
-
-	function urlStyleTest( selector, prop, val ) {
-		return QUnit.fixurl(
-			mw.config.get( 'wgScriptPath' ) +
-				'/tests/qunit/data/styleTest.css.php?' +
-				$.param( {
-					selector: selector,
-					prop: prop,
-					val: val
-				} )
-		);
-	}
-
-	QUnit.test( 'mw.loader', 2, function ( assert ) {
-		var isAwesomeDone;
-
-		mw.loader.testCallback = function () {
-			assert.strictEqual( isAwesomeDone, undefined, 'Implementing module is.awesome: isAwesomeDone should still be undefined' );
-			isAwesomeDone = true;
-		};
-
-		mw.loader.implement( 'test.callback', [ QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/callMwLoaderTestCallback.js' ) ] );
-
-		return mw.loader.using( 'test.callback', function () {
-			assert.strictEqual( isAwesomeDone, true, 'test.callback module should\'ve caused isAwesomeDone to be true' );
-			delete mw.loader.testCallback;
-
-		}, function () {
-			assert.ok( false, 'Error callback fired while loader.using "test.callback" module' );
-		} );
-	} );
-
-	QUnit.test( 'mw.loader with Object method as module name', 2, function ( assert ) {
-		var isAwesomeDone;
-
-		mw.loader.testCallback = function () {
-			assert.strictEqual( isAwesomeDone, undefined, 'Implementing module hasOwnProperty: isAwesomeDone should still be undefined' );
-			isAwesomeDone = true;
-		};
-
-		mw.loader.implement( 'hasOwnProperty', [ QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/callMwLoaderTestCallback.js' ) ], {}, {} );
-
-		return mw.loader.using( 'hasOwnProperty', function () {
-			assert.strictEqual( isAwesomeDone, true, 'hasOwnProperty module should\'ve caused isAwesomeDone to be true' );
-			delete mw.loader.testCallback;
-
-		}, function () {
-			assert.ok( false, 'Error callback fired while loader.using "hasOwnProperty" module' );
-		} );
-	} );
-
-	QUnit.test( 'mw.loader.using( .. ) Promise', 2, function ( assert ) {
-		var isAwesomeDone;
-
-		mw.loader.testCallback = function () {
-			assert.strictEqual( isAwesomeDone, undefined, 'Implementing module is.awesome: isAwesomeDone should still be undefined' );
-			isAwesomeDone = true;
-		};
-
-		mw.loader.implement( 'test.promise', [ QUnit.fixurl( mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/callMwLoaderTestCallback.js' ) ] );
-
-		return mw.loader.using( 'test.promise' )
-		.done( function () {
-			assert.strictEqual( isAwesomeDone, true, 'test.promise module should\'ve caused isAwesomeDone to be true' );
-			delete mw.loader.testCallback;
-
-		} )
-		.fail( function () {
-			assert.ok( false, 'Error callback fired while loader.using "test.promise" module' );
-		} );
-	} );
-
-	QUnit.test( 'mw.loader.implement( styles={ "css": [text, ..] } )', 2, function ( assert ) {
-		var $element = $( '<div class="mw-test-implement-a"></div>' ).appendTo( '#qunit-fixture' );
-
-		assert.notEqual(
-			$element.css( 'float' ),
-			'right',
-			'style is clear'
-		);
-
-		mw.loader.implement(
-			'test.implement.a',
-			function () {
-				assert.equal(
-					$element.css( 'float' ),
-					'right',
-					'style is applied'
-				);
-			},
-			{
-				all: '.mw-test-implement-a { float: right; }'
-			}
-		);
-
-		return mw.loader.using( 'test.implement.a' );
-	} );
-
-	QUnit.test( 'mw.loader.implement( styles={ "url": { <media>: [url, ..] } } )', 7, function ( assert ) {
-		var $element1 = $( '<div class="mw-test-implement-b1"></div>' ).appendTo( '#qunit-fixture' ),
-			$element2 = $( '<div class="mw-test-implement-b2"></div>' ).appendTo( '#qunit-fixture' ),
-			$element3 = $( '<div class="mw-test-implement-b3"></div>' ).appendTo( '#qunit-fixture' ),
-			done = assert.async();
-
-		assert.notEqual(
-			$element1.css( 'text-align' ),
-			'center',
-			'style is clear'
-		);
-		assert.notEqual(
-			$element2.css( 'float' ),
-			'left',
-			'style is clear'
-		);
-		assert.notEqual(
-			$element3.css( 'text-align' ),
-			'right',
-			'style is clear'
-		);
-
-		mw.loader.implement(
-			'test.implement.b',
-			function () {
-				// Note: done() must only be called when the entire test is
-				// complete. So, make sure that we don't start until *both*
-				// assertStyleAsync calls have completed.
-				var pending = 2;
-				assertStyleAsync( assert, $element2, 'float', 'left', function () {
-					assert.notEqual( $element1.css( 'text-align' ), 'center', 'print style is not applied' );
-
-					pending--;
-					if ( pending === 0 ) {
-						done();
-					}
-				} );
-				assertStyleAsync( assert, $element3, 'float', 'right', function () {
-					assert.notEqual( $element1.css( 'text-align' ), 'center', 'print style is not applied' );
-
-					pending--;
-					if ( pending === 0 ) {
-						done();
-					}
-				} );
-			},
-			{
-				url: {
-					print: [ urlStyleTest( '.mw-test-implement-b1', 'text-align', 'center' ) ],
-					screen: [
-						// bug 40834: Make sure it actually works with more than 1 stylesheet reference
-						urlStyleTest( '.mw-test-implement-b2', 'float', 'left' ),
-						urlStyleTest( '.mw-test-implement-b3', 'float', 'right' )
-					]
-				}
-			}
-		);
-
-		mw.loader.load( 'test.implement.b' );
-	} );
-
-	// Backwards compatibility
-	QUnit.test( 'mw.loader.implement( styles={ <media>: text } ) (back-compat)', 2, function ( assert ) {
-		var $element = $( '<div class="mw-test-implement-c"></div>' ).appendTo( '#qunit-fixture' );
-
-		assert.notEqual(
-			$element.css( 'float' ),
-			'right',
-			'style is clear'
-		);
-
-		mw.loader.implement(
-			'test.implement.c',
-			function () {
-				assert.equal(
-					$element.css( 'float' ),
-					'right',
-					'style is applied'
-				);
-			},
-			{
-				all: '.mw-test-implement-c { float: right; }'
-			}
-		);
-
-		return mw.loader.using( 'test.implement.c' );
-	} );
-
-	// Backwards compatibility
-	QUnit.test( 'mw.loader.implement( styles={ <media>: [url, ..] } ) (back-compat)', 4, function ( assert ) {
-		var $element = $( '<div class="mw-test-implement-d"></div>' ).appendTo( '#qunit-fixture' ),
-			$element2 = $( '<div class="mw-test-implement-d2"></div>' ).appendTo( '#qunit-fixture' ),
-			done = assert.async();
-
-		assert.notEqual(
-			$element.css( 'float' ),
-			'right',
-			'style is clear'
-		);
-		assert.notEqual(
-			$element2.css( 'text-align' ),
-			'center',
-			'style is clear'
-		);
-
-		mw.loader.implement(
-			'test.implement.d',
-			function () {
-				assertStyleAsync( assert, $element, 'float', 'right', function () {
-					assert.notEqual( $element2.css( 'text-align' ), 'center', 'print style is not applied (bug 40500)' );
-					done();
-				} );
-			},
-			{
-				all: [ urlStyleTest( '.mw-test-implement-d', 'float', 'right' ) ],
-				print: [ urlStyleTest( '.mw-test-implement-d2', 'text-align', 'center' ) ]
-			}
-		);
-
-		mw.loader.load( 'test.implement.d' );
-	} );
-
-	// @import (bug 31676)
-	QUnit.test( 'mw.loader.implement( styles has @import )', 7, function ( assert ) {
-		var isJsExecuted, $element,
-			done = assert.async();
-
-		mw.loader.implement(
-			'test.implement.import',
-			function () {
-				assert.strictEqual( isJsExecuted, undefined, 'script not executed multiple times' );
-				isJsExecuted = true;
-
-				assert.equal( mw.loader.getState( 'test.implement.import' ), 'executing', 'module state during implement() script execution' );
-
-				$element = $( '<div class="mw-test-implement-import">Foo bar</div>' ).appendTo( '#qunit-fixture' );
-
-				assert.equal( mw.msg( 'test-foobar' ), 'Hello Foobar, $1!', 'messages load before script execution' );
-
-				assertStyleAsync( assert, $element, 'float', 'right', function () {
-					assert.equal( $element.css( 'text-align' ), 'center',
-						'CSS styles after the @import rule are working'
-					);
-
-					done();
-				} );
-			},
-			{
-				css: [
-					'@import url(\''
-						+ urlStyleTest( '.mw-test-implement-import', 'float', 'right' )
-						+ '\');\n'
-						+ '.mw-test-implement-import { text-align: center; }'
-				]
-			},
-			{
-				'test-foobar': 'Hello Foobar, $1!'
-			}
-		);
-
-		mw.loader.using( 'test.implement.import' ).always( function () {
-			assert.strictEqual( isJsExecuted, true, 'script executed' );
-			assert.equal( mw.loader.getState( 'test.implement.import' ), 'ready', 'module state after script execution' );
-		} );
-	} );
-
-	QUnit.test( 'mw.loader.implement( dependency with styles )', 4, function ( assert ) {
-		var $element = $( '<div class="mw-test-implement-e"></div>' ).appendTo( '#qunit-fixture' ),
-			$element2 = $( '<div class="mw-test-implement-e2"></div>' ).appendTo( '#qunit-fixture' );
-
-		assert.notEqual(
-			$element.css( 'float' ),
-			'right',
-			'style is clear'
-		);
-		assert.notEqual(
-			$element2.css( 'float' ),
-			'left',
-			'style is clear'
-		);
-
-		mw.loader.register( [
-			[ 'test.implement.e', '0', [ 'test.implement.e2' ] ],
-			[ 'test.implement.e2', '0' ]
-		] );
-
-		mw.loader.implement(
-			'test.implement.e',
-			function () {
-				assert.equal(
-					$element.css( 'float' ),
-					'right',
-					'Depending module\'s style is applied'
-				);
-			},
-			{
-				all: '.mw-test-implement-e { float: right; }'
-			}
-		);
-
-		mw.loader.implement(
-			'test.implement.e2',
-			function () {
-				assert.equal(
-					$element2.css( 'float' ),
-					'left',
-					'Dependency\'s style is applied'
-				);
-			},
-			{
-				all: '.mw-test-implement-e2 { float: left; }'
-			}
-		);
-
-		return mw.loader.using( 'test.implement.e' );
-	} );
-
-	QUnit.test( 'mw.loader.implement( only scripts )', 1, function ( assert ) {
-		mw.loader.implement( 'test.onlyscripts', function () {} );
-		assert.strictEqual( mw.loader.getState( 'test.onlyscripts' ), 'ready' );
-	} );
-
-	QUnit.test( 'mw.loader.implement( only messages )', 2, function ( assert ) {
-		assert.assertFalse( mw.messages.exists( 'bug_29107' ), 'Verify that the test message doesn\'t exist yet' );
-
-		// jscs: disable requireCamelCaseOrUpperCaseIdentifiers
-		mw.loader.implement( 'test.implement.msgs', [], {}, { bug_29107: 'loaded' } );
-		// jscs: enable requireCamelCaseOrUpperCaseIdentifiers
-
-		return mw.loader.using( 'test.implement.msgs', function () {
-			assert.ok( mw.messages.exists( 'bug_29107' ), 'Bug 29107: messages-only module should implement ok' );
-		}, function () {
-			assert.ok( false, 'Error callback fired while implementing "test.implement.msgs" module' );
-		} );
-	} );
-
-	QUnit.test( 'mw.loader.implement( empty )', 1, function ( assert ) {
-		mw.loader.implement( 'test.empty' );
-		assert.strictEqual( mw.loader.getState( 'test.empty' ), 'ready' );
-	} );
-
-	QUnit.test( 'mw.loader with broken indirect dependency', 4, function ( assert ) {
-		// don't emit an error event
-		this.sandbox.stub( mw, 'track' );
-
-		mw.loader.register( [
-			[ 'test.module1', '0' ],
-			[ 'test.module2', '0', [ 'test.module1' ] ],
-			[ 'test.module3', '0', [ 'test.module2' ] ]
-		] );
-		mw.loader.implement( 'test.module1', function () {
-			throw new Error( 'expected' );
-		}, {}, {} );
-		assert.strictEqual( mw.loader.getState( 'test.module1' ), 'error', 'Expected "error" state for test.module1' );
-		assert.strictEqual( mw.loader.getState( 'test.module2' ), 'error', 'Expected "error" state for test.module2' );
-		assert.strictEqual( mw.loader.getState( 'test.module3' ), 'error', 'Expected "error" state for test.module3' );
-
-		assert.strictEqual( mw.track.callCount, 1 );
-	} );
-
-	QUnit.test( 'mw.loader with circular dependency', 1, function ( assert ) {
-		mw.loader.register( [
-			[ 'test.circle1', '0', [ 'test.circle2' ] ],
-			[ 'test.circle2', '0', [ 'test.circle3' ] ],
-			[ 'test.circle3', '0', [ 'test.circle1' ] ]
-		] );
-		assert.throws( function () {
-			mw.loader.using( 'test.circle3' );
-		}, /Circular/, 'Detect circular dependency' );
-	} );
-
-	QUnit.test( 'mw.loader out-of-order implementation', 9, function ( assert ) {
-		mw.loader.register( [
-			[ 'test.module4', '0' ],
-			[ 'test.module5', '0', [ 'test.module4' ] ],
-			[ 'test.module6', '0', [ 'test.module5' ] ]
-		] );
-		mw.loader.implement( 'test.module4', function () {} );
-		assert.strictEqual( mw.loader.getState( 'test.module4' ), 'ready', 'Expected "ready" state for test.module4' );
-		assert.strictEqual( mw.loader.getState( 'test.module5' ), 'registered', 'Expected "registered" state for test.module5' );
-		assert.strictEqual( mw.loader.getState( 'test.module6' ), 'registered', 'Expected "registered" state for test.module6' );
-		mw.loader.implement( 'test.module6', function () {} );
-		assert.strictEqual( mw.loader.getState( 'test.module4' ), 'ready', 'Expected "ready" state for test.module4' );
-		assert.strictEqual( mw.loader.getState( 'test.module5' ), 'registered', 'Expected "registered" state for test.module5' );
-		assert.strictEqual( mw.loader.getState( 'test.module6' ), 'loaded', 'Expected "loaded" state for test.module6' );
-		mw.loader.implement( 'test.module5', function () {} );
-		assert.strictEqual( mw.loader.getState( 'test.module4' ), 'ready', 'Expected "ready" state for test.module4' );
-		assert.strictEqual( mw.loader.getState( 'test.module5' ), 'ready', 'Expected "ready" state for test.module5' );
-		assert.strictEqual( mw.loader.getState( 'test.module6' ), 'ready', 'Expected "ready" state for test.module6' );
-	} );
-
-	QUnit.test( 'mw.loader missing dependency', 13, function ( assert ) {
-		mw.loader.register( [
-			[ 'test.module7', '0' ],
-			[ 'test.module8', '0', [ 'test.module7' ] ],
-			[ 'test.module9', '0', [ 'test.module8' ] ]
-		] );
-		mw.loader.implement( 'test.module8', function () {} );
-		assert.strictEqual( mw.loader.getState( 'test.module7' ), 'registered', 'Expected "registered" state for test.module7' );
-		assert.strictEqual( mw.loader.getState( 'test.module8' ), 'loaded', 'Expected "loaded" state for test.module8' );
-		assert.strictEqual( mw.loader.getState( 'test.module9' ), 'registered', 'Expected "registered" state for test.module9' );
-		mw.loader.state( 'test.module7', 'missing' );
-		assert.strictEqual( mw.loader.getState( 'test.module7' ), 'missing', 'Expected "missing" state for test.module7' );
-		assert.strictEqual( mw.loader.getState( 'test.module8' ), 'error', 'Expected "error" state for test.module8' );
-		assert.strictEqual( mw.loader.getState( 'test.module9' ), 'error', 'Expected "error" state for test.module9' );
-		mw.loader.implement( 'test.module9', function () {} );
-		assert.strictEqual( mw.loader.getState( 'test.module7' ), 'missing', 'Expected "missing" state for test.module7' );
-		assert.strictEqual( mw.loader.getState( 'test.module8' ), 'error', 'Expected "error" state for test.module8' );
-		assert.strictEqual( mw.loader.getState( 'test.module9' ), 'error', 'Expected "error" state for test.module9' );
-		mw.loader.using(
-			[ 'test.module7' ],
-			function () {
-				assert.ok( false, 'Success fired despite missing dependency' );
-				assert.ok( true, 'QUnit expected() count dummy' );
-			},
-			function ( e, dependencies ) {
-				assert.strictEqual( $.isArray( dependencies ), true, 'Expected array of dependencies' );
-				assert.deepEqual( dependencies, [ 'test.module7' ], 'Error callback called with module test.module7' );
-			}
-		);
-		mw.loader.using(
-			[ 'test.module9' ],
-			function () {
-				assert.ok( false, 'Success fired despite missing dependency' );
-				assert.ok( true, 'QUnit expected() count dummy' );
-			},
-			function ( e, dependencies ) {
-				assert.strictEqual( $.isArray( dependencies ), true, 'Expected array of dependencies' );
-				dependencies.sort();
-				assert.deepEqual(
-					dependencies,
-					[ 'test.module7', 'test.module8', 'test.module9' ],
-					'Error callback called with all three modules as dependencies'
-				);
-			}
-		);
-	} );
-
-	QUnit.test( 'mw.loader dependency handling', 5, function ( assert ) {
-		var done = assert.async();
-		mw.loader.register( [
-			// [module, version, dependencies, group, source]
-			[ 'testMissing', '1', [], null, 'testloader' ],
-			[ 'testUsesMissing', '1', [ 'testMissing' ], null, 'testloader' ],
-			[ 'testUsesNestedMissing', '1', [ 'testUsesMissing' ], null, 'testloader' ]
-		] );
-
-		function verifyModuleStates() {
-			assert.equal( mw.loader.getState( 'testMissing' ), 'missing', 'Module not known to server must have state "missing"' );
-			assert.equal( mw.loader.getState( 'testUsesMissing' ), 'error', 'Module with missing dependency must have state "error"' );
-			assert.equal( mw.loader.getState( 'testUsesNestedMissing' ), 'error', 'Module with indirect missing dependency must have state "error"' );
-		}
-
-		mw.loader.using( [ 'testUsesNestedMissing' ],
-			function () {
-				assert.ok( false, 'Error handler should be invoked.' );
-				assert.ok( true ); // Dummy to reach QUnit expect()
-
-				verifyModuleStates();
-
-				done();
-			},
-			function ( e, badmodules ) {
-				assert.ok( true, 'Error handler should be invoked.' );
-				// As soon as server spits out state('testMissing', 'missing');
-				// it will bubble up and trigger the error callback.
-				// Therefor the badmodules array is not testUsesMissing or testUsesNestedMissing.
-				assert.deepEqual( badmodules, [ 'testMissing' ], 'Bad modules as expected.' );
-
-				verifyModuleStates();
-
-				done();
-			}
-		);
-	} );
-
-	QUnit.test( 'mw.loader skin-function handling', 5, function ( assert ) {
-		mw.loader.register( [
-			// [module, version, dependencies, group, source, skip]
-			[ 'testSkipped', '1', [], null, 'testloader', 'return true;' ],
-			[ 'testNotSkipped', '1', [], null, 'testloader', 'return false;' ],
-			[ 'testUsesSkippable', '1', [ 'testSkipped', 'testNotSkipped' ], null, 'testloader' ]
-		] );
-
-		function verifyModuleStates() {
-			assert.equal( mw.loader.getState( 'testSkipped' ), 'ready', 'Module is ready when skipped' );
-			assert.equal( mw.loader.getState( 'testNotSkipped' ), 'ready', 'Module is ready when not skipped but loaded' );
-			assert.equal( mw.loader.getState( 'testUsesSkippable' ), 'ready', 'Module is ready when skippable dependencies are ready' );
-		}
-
-		return mw.loader.using( [ 'testUsesSkippable' ],
-			function () {
-				assert.ok( true, 'Success handler should be invoked.' );
-				assert.ok( true ); // Dummy to match error handler and reach QUnit expect()
-
-				verifyModuleStates();
-			},
-			function ( e, badmodules ) {
-				assert.ok( false, 'Error handler should not be invoked.' );
-				assert.deepEqual( badmodules, [], 'Bad modules as expected.' );
-
-				verifyModuleStates();
-			}
-		);
-	} );
-
-	QUnit.asyncTest( 'mw.loader( "//protocol-relative" ) (bug 30825)', 2, function ( assert ) {
-		// This bug was actually already fixed in 1.18 and later when discovered in 1.17.
-		// Test is for regressions!
-
-		// Forge a URL to the test callback script
-		var target = QUnit.fixurl(
-			mw.config.get( 'wgServer' ) + mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/qunitOkCall.js'
-		);
-
-		// Confirm that mw.loader.load() works with protocol-relative URLs
-		target = target.replace( /https?:/, '' );
-
-		assert.equal( target.slice( 0, 2 ), '//',
-			'URL must be relative to test relative URLs!'
-		);
-
-		// Async!
-		// The target calls QUnit.start
-		mw.loader.load( target );
-	} );
-
-	QUnit.asyncTest( 'mw.loader( "/absolute-path" )', 2, function ( assert ) {
-		// Forge a URL to the test callback script
-		var target = QUnit.fixurl(
-			mw.config.get( 'wgScriptPath' ) + '/tests/qunit/data/qunitOkCall.js'
-		);
-
-		// Confirm that mw.loader.load() works with absolute-paths (relative to current hostname)
-		assert.equal( target.slice( 0, 1 ), '/', 'URL is relative to document root' );
-
-		// Async!
-		// The target calls QUnit.start
-		mw.loader.load( target );
-	} );
-
-	QUnit.test( 'mw.loader() executing race (T112232)', 2, function ( assert ) {
-		var done = false;
-
-		// The red herring schedules its CSS buffer first. In T112232, a bug in the
-		// state machine would cause the job for testRaceLoadMe to run with an earlier job.
-		mw.loader.implement(
-			'testRaceRedHerring',
-			function () {},
-			{ css: [ '.mw-testRaceRedHerring {}' ] }
-		);
-		mw.loader.implement(
-			'testRaceLoadMe',
-			function () {
-				done = true;
-			},
-			{ css: [ '.mw-testRaceLoadMe { float: left; }' ] }
-		);
-
-		mw.loader.load( [ 'testRaceRedHerring', 'testRaceLoadMe' ] );
-		return mw.loader.using( 'testRaceLoadMe', function () {
-			assert.strictEqual( done, true, 'script ran' );
-			assert.strictEqual( mw.loader.getState( 'testRaceLoadMe' ), 'ready', 'state' );
-		} );
-	} );
-
 	QUnit.test( 'mw.hook', 13, function ( assert ) {
 		var hook, add, fire, chars, callback;
 
@@ -1054,67 +436,4 @@
 		);
 	} );
 
-	QUnit.test( 'mw.loader require()', 6, function ( assert ) {
-		mw.loader.register( [
-			[ 'test.require1', '0' ],
-			[ 'test.require2', '0' ],
-			[ 'test.require3', '0' ],
-			[ 'test.require4', '0', [ 'test.require3' ] ]
-		] );
-		mw.loader.implement( 'test.require1', function () {} );
-		mw.loader.implement( 'test.require2', function ( $, jQuery, require, module ) {
-			module.exports = 1;
-		} );
-		mw.loader.implement( 'test.require3', function ( $, jQuery, require, module ) {
-			module.exports = function () {
-				return 'hello world';
-			};
-		} );
-		mw.loader.implement( 'test.require4', function ( $, jQuery, require, module ) {
-			var other = require( 'test.require3' );
-			module.exports = {
-				pizza: function () {
-					return other();
-				}
-			};
-		} );
-		return mw.loader.using( [ 'test.require1', 'test.require2', 'test.require3', 'test.require4' ] )
-		.then( function ( require ) {
-			var module1, module2, module3, module4;
-
-			module1 = require( 'test.require1' );
-			module2 = require( 'test.require2' );
-			module3 = require( 'test.require3' );
-			module4 = require( 'test.require4' );
-
-			assert.strictEqual( typeof module1, 'object', 'export of module with no export' );
-			assert.strictEqual( module2, 1, 'export a number' );
-			assert.strictEqual( module3(), 'hello world', 'export a function' );
-			assert.strictEqual( typeof module4.pizza, 'function', 'export an object' );
-			assert.strictEqual( module4.pizza(), 'hello world', 'module can require other modules' );
-
-			assert.throws( function () {
-				require( '_badmodule' );
-			}, /is not loaded/, 'Requesting non-existent modules throws error.' );
-		} );
-	} );
-
-	QUnit.test( 'mw.loader require() in debug mode', 1, function ( assert ) {
-		var path = mw.config.get( 'wgScriptPath' );
-		mw.loader.register( [
-			[ 'test.require.define', '0' ],
-			[ 'test.require.callback', '0', [ 'test.require.define' ] ]
-		] );
-		mw.loader.implement( 'test.require.callback', [ QUnit.fixurl( path + '/tests/qunit/data/requireCallMwLoaderTestCallback.js' ) ] );
-		mw.loader.implement( 'test.require.define', [ QUnit.fixurl( path + '/tests/qunit/data/defineCallMwLoaderTestCallback.js' ) ] );
-
-		return mw.loader.using( 'test.require.callback' ).then( function ( require ) {
-			var exported = require( 'test.require.callback' );
-			assert.strictEqual( exported, 'Require worked.Define worked.',
-				'module.exports worked in debug mode' );
-		}, function () {
-			assert.ok( false, 'Error callback fired while loader.using "test.require.callback" module' );
-		} );
-	} );
-
-}( mediaWiki, jQuery ) );
+}( mediaWiki ) );