Release notes/1.37

= MediaWiki 1.37 =

MediaWiki 1.37.3
This is a security and maintenance release of the MediaWiki 1.37 branch.

Changes since MediaWiki 1.37.2
triggered.
 * Localisation updates.
 * (T289879) Type hints for ArrayAccess and JsonSerializable.
 * (T304783) TemplateParser: avoid warnings when called by NoLocalSettings.
 * Rebuilt vendor with composer 2.3.3.
 * Fix old_name in UserLogoutComplete hook.
 * (T289879) Address some deprecations for PHP 8.1.
 * (T193565) UserGroupManager: Fix dbDomain in addUserToGroup deferred update.
 * (T309114) LocalFile::prerenderThumbnails: Limit the number of thumbnail jobs
 * (T307982) Updated wikimedia/parsoid from v0.14.0 to v0.14.1.
 * (T308471) SECURITY: Escape welcomeuser message passed to showSuccessPage.
 * (T308473) SECURITY: Escape contributions-title msg for use within page title.
 * (T311272) Call parent constructor of AddSite maintenance script first.
 * MediaWiki: Don't eagerly initialize action name.
 * Updated wikimedia/shellbox from v2.0.0 to v2.1.1.
 * (T311384, CVE-2022-27776) Updated guzzlehttp/guzzle from 7.2.0 to 7.4.5.
 * (T289926) Avoid passing null to trim in SkinTemplate.
 * (T311473) rollbackEdits: Pass user identity to RollbackPage.
 * (T307282) Avoid passing null to strcasecmp, for PHP 8.1.
 * (T311551) ShellboxClientFactory::getUrl: Check if $this->key is null.
 * (T311552) ChangesListSpecialPage: Don't pass null to FormatJson::decode.
 * (T311569) FileBackend::isStoragePath Handle being passed null.
 * (T311544) Pass int to ApiUsageException::newWithMessage's $httpCode param.
 * (T311678) SpecialEditWatchlist: Prevent passing null to strtolower.
 * (T281741) ChangeTags: Fix adding CSS classes for hidden tags.
 * (T296642) changetags: Fix management of a '0' tag.
 * (T311554) ChangeTags: Return early in formatSummaryRow if $tags === null.
 * (T303033) Handle null in ChangeTags::modifyDisplayQuery.
 * Updated wikimedia/common-passwords from 0.3.0 to 0.4.0.

MediaWiki 1.37.2
This is a security and maintenance release of the MediaWiki 1.37 branch.

Changes since MediaWiki 1.37.1

 * (T298261) Fix support for Composer 2.2.
 * (T298283) composer.json: Add wikimedia/composer-merge-plugin to allow-plugins.
 * Update doctrine/dbal (3.0.0 => 3.1.5).
 * (T296898) Add entry point name to disabled Session exception if possible.
 * (T298564) MemcachedClient: Add support for IPv6.
 * (T297543, CVE-2022-28202) SECURITY: properly escape output used within galleries and Special:RevisionDelete.
 * (T289956) WatchAction: Fix bug that prevents showing proper success message in the noscript fallback mode.
 * (T268847) Suppress deprecation warnings from libxml_disable_entity_loader.
 * (T283275) Fix PHP 8.0 failure of RefreshSecondaryDataUpdateTest.
 * (T283275) Fix PHP 8.0 failure of WikiExporterFactoryTest.
 * (T275673) objectcache: Avoid getCurrentTime call in MapCacheLRU::has.
 * (T275673) objectcache: split up MapCacheLRU::getAge to avoid conditional overhead.
 * Fix the json schema and the extension processor for Parsoid extension modules.
 * (T299696) update.php: Avoid passing null to substr.
 * (T195807, T256401) Fix signature of DatabasePostgres::buildGroupConcatField.
 * In PHP 8.1 don't throw exceptions from mysqli.
 * (T289926) SiteConfiguration: Don't pass null to str_replace.
 * (T264735) Fix deprecation warning from CURLPIPE_HTTP1.
 * (T260735) Stop using is_resource where possible.
 * (T289879) Apply ReturnTypeWillChange to various implementations of built in interfaces.
 * (T299312) Implement __serialize/__unserialize for PHP 8.1 support.
 * ExtensionRegistry: Add process cache for lazy attributes.
 * (T301041) ApiPageSet: Add "missing": true to missing revisions.
 * Allow ParsoidModules extension schema to register services.
 * (T300462) SpecialUndelete: Do not show empty comments as deleted.
 * (T297708) Allow setting max execution time to several special pages.
 * (T205349) LinkCache: Try invalidating cache before throwing.
 * (T302540) composer.json: Add ext-calendar to require.
 * (T302540) composer.json: Add ext-simplexml to require-dev.
 * (T302540) composer.json: Add various PHP extensions to suggests.
 * Upgrading symfony/polyfill-php80 (v1.23.1 => v1.25.0).
 * (T304008) Don't re-check "Move subpages" on Special:MovePage after a warning.
 * (T293576) listFiles: Display file name instead of version.
 * (T303871) Fix @since of Title::getId.
 * (T303560) Installer: Check correct PCRE_CONFIG_NEWLINE value.
 * wrapOldPasswords: add \n to two output calls.
 * (T297571, CVE-2022-28201) Title::newMainPage goes into an infinite recursion loop if it points to a local interwiki.
 * (T297731, CVE-2022-28203) Requesting Special:NewFiles on a wiki with many file uploads with actor as a condition can result in a DoS.
 * (T297754, CVE-2022-28204) Special:WhatLinksHere can result in a DoS when a page is used on a extremely large number of other pages.

MediaWiki 1.37.1
This is a security and maintenance release of the MediaWiki 1.37 branch.

Changes since MediaWiki 1.37.0

 * (T296112) Allow inserting new sections named '0'.
 * Fix path for ZhConversion.php.
 * nukeNS: don't run purgeRedundantText after every change.
 * (T286779, T297031) installer: Fix Postgres mistakes in using changeField method.
 * (T225888) RollbackAction: fix missing pagetitle.
 * (T297322, CVE-2021-44858, CVE-2021-44857) SECURITY: Fix permissions checks in undo actions.
 * (T297574, CVE-2021-45038) SECURITY: Fix permissions check in action=rollback.
 * (T34716, T297416) SECURITY: Require 'read' right for most actions.
 * (T271037, CVE-2021-44856) SECURITY: Fix use of EditFilterMergedContent hook when changing content model.

Changes since MediaWiki 1.37.0-rc.2

 * Remove justinrainbow/json-schema from vendor.
 * Updated pear/mail_mime from 1.10.9 to 1.10.11.
 * Update deprecated Guzzle Psr7 function calls.
 * (T281972) UserIdentityValue: Correct @since tags.
 * Updated wikimedia/parsoid from v0.14.0-a19 to v0.14.0.
 * Localisation updates.
 * Tweak error message for missing composer dependencies.

Changes since MediaWiki 1.37.0-rc.1

 * (T295173) Re-add wikimedia/normalized-exception to vendor.
 * Remove wikimedia/testing-access-wrapper, psr/simple-cache, psr/http-factory from vendor.
 * (T295191) ApiQuerySiteinfo: Fix "rightsinfo"/"url" when $wgRightsPage is set.
 * (T212428) Allow populateContentTables to continue when there are bad blobs.

Changes since MediaWiki 1.37.0-rc.0

 * (T294043) checkStorage: pass no parameters to WikiRevision::getContent.
 * (T292763,CVE-2021-44856) SECURITY: Do not cache private wiki completion results.
 * (T293783) ApiQueryImageInfo: don't show empty comments as deleted.
 * (T294316) Revert "Mark ApiClientLogin/ApiLogin as requiring write mode".
 * (T294796) JobQueueRedis: Replace deprecated zSize with zCard.
 * Remove duplicate settings from DefaultSettings.
 * (T278037) NoLocalSettings: Pass an EmptyBagOStuff to TemplateParser.

Upgrading notes for 1.37
Don't forget to always back up your database before upgrading!

See the file UPGRADE for more detailed per-version upgrade instructions from the oldest supported upgrading version, MediaWiki 1.27.

Some specific notes for MediaWiki 1.37 upgrades are below:
 * (T280806) Deprecated methods of fetching API tokens have been removed. This may cause older bots and scripts to fail. Most queries are trivially updateable to using new methods. See the Action API changes section below for more information.

For notes on 1.36.x and older releases, see HISTORY.

Configuration changes for system administrators in 1.37

 * (T242768) The PasswordCannotMatchUsername password policy has been removed, please use PasswordCannotBeSubstringInUsername instead. If you have not customised your password policies, there will be nothing to do here.

New configuration

 * $wgBrowserFormatDetection - This setting allows the enabling or disabling of automatic detection of possible phone numbers in a webpage in iOS Safari.
 * $wgParserEnableLegacyMediaDOM - This setting defaults to true, and enables the legacy media HTML structure in the output from the Parser. The alternative modern HTML structure for media is described at https://www.mediawiki.org/wiki/Parsing/Media_structure. In a future release of MediaWiki this option will default to false, so it's a good idea to test this setting on your wiki early and report any issues.

Changed configuration

 * $wgContentHandlerTextFallback - This migration setting, which defines how to react if a plain text version of a non-text Content object is requested using ContentHandler::getContentText, is deprecated.
 * $wgActions – This setting lets sysadmins override which actions can be used. It has been re-worked to support injecting dependencies into Action sub-classes as part of wider work on dependency injection. Previously, $wgActions was an array where the keys were the names of actions, and the values had the following impacts (for a given key 'Foo'):
 * `true`: use the class 'FooAction' unless for a specific page WikiPage::getActionOverrides wants to override that action
 * a string: use the class with that name, and do not allow over-riding on a per-page basis
 * `false`: the action is disabled
 * a callable: use the Action instance returned by invoking that callback, and do not allow overriding on a per-page basis
 * an object: use that specific Action instance, and do not allow overriding on a per-page basis.

As part of T253078, values can now be arrays that are not callables, which are treated as ObjectFactory specs, allowing for services to be injected. Additionally, the distinction between values that allow per-page overrides and those that do not was removed - all actions can now be overridden on a per-page basis using WikiPage::getActionOverrides.
 * $wgShellboxUrl – This setting, new in 1.36 to configure the novel Shellbox encapsulation system, is now deprecated; use $wgShellboxUrls as a mapping of service => URL instead.
 * $wgIncludejQueryMigrate – This setting, introduced in 1.29 to on whether to provide a migration layer for jQuery, has now switched its default value from true to false. This may break gadgets that depended on methods that were removed in jQuery 3 in 2017. See T280944 for more information.
 * A number of settings have been renamed. The former configuration variable names are deprecated, but will be used as the fall back if they are still set, and remain temporarily available for extensions which might try to read them:
 * $wgFileBlacklist is now $wgProhibitedFileExtensions
 * $wgMimeTypeBlacklist is now $wgMimeTypeExclusions
 * $wgEnableUserEmailBlacklist is now $wgEnableUserEmailMuteList
 * $wgShortPagesNamespaceBlacklist is now $wgShortPagesNamespaceExclusions
 * $wgMimeTypeExclusions - As well as being renamed, this configuration array now also prohibits the RFC 4329 form of JavaScript, 'application/javascript', as well as previous MIME types.
 * $wgFragmentMode - This setting, which determines the encoding of section IDs, has now switched its default value from legacy-first to html5-first: both the HTML5 anchor and the legacy percent-encoding-style anchor will still be generated for section titles, but references to them will use the HTML5 version, resulting in human-readable fragments.

Removed configuration

 * $wgLegacyJavaScriptGlobals, deprecated in 1.36.
 * (T274695) $wgAjaxEditStash, deprecated in 1.36.
 * $wgShowDBErrorBacktrace, deprecated and non-functional since 1.32.
 * $wgShowSQLErrors, deprecated and non-functional since 1.32.
 * $wgLangObjCacheSize, without deprecation; the LanguageFactory service now always retains at most 10 objects in its LRU-cache.
 * $wgDjvuToXML, without deprecation; the tool it enables is obsolete and abandoned upstream. Use $wgDjvuDump to use that tool instead.

New user-facing features in 1.37

 * (T161934) MediaWiki now supports JPEG2000 files, to a limited extent.

New external libraries

 * Added symfony/polyfill-php80 1.23.1.
 * Added whatwg-fetch 3.6.2.
 * Added wikimedia/normalized-exception 1.0.1.

Changed external libraries

 * Updated OOjs from v5.0.0 to v6.0.0
 * Updated OOjs-Router from v0.2.0 to v0.3.0
 * Updated OOUI from v0.41.3 to v0.42.0
 * Updated WVUI from v0.1.0 to v0.3.0
 * Updated cssjanus/cssjanus from v1.3.0 to v2.1.0.
 * Updated psr/container from v1.0.0 to v1.1.1.
 * Updated wikimedia/minify from v2.2.2 to v2.2.4.
 * Updated wikimedia/object-factory from v3.0.0 to v3.0.2.
 * Updated wikimedia/parsoid from v0.13.1 to v0.14.0-a19.
 * Updated wikimedia/relpath from v2.1.1 to v3.0.0.
 * Updated wikimedia/remex-html from v2.3.1 to v2.3.2.
 * Updated wikimedia/shellbox from v1.0.4 to v2.0.0.
 * Updated wikimedia/wait-condition-loop from v2.0.1 to v2.0.2.
 * Updated zordius/lightncandy from v1.2.5 to v1.2.6.

Changed development-only external libraries

 * Updated qunit from 2.10.0 to 2.16.0.

Removed external libraries

 * The pimple/pimple development-only library has been removed.

Action API changes in 1.37

 * (T280806) The API methods for fetching tokens which were deprecated in MediaWiki 1.24 have been removed. action=query&meta=tokens&type= should be used instead. Please note some token types no longer exist, and you should just use type=csrf for those instead.
 * action=query&prop=info&intoken -> action=query&meta=tokens&type=csrf
 * action=tokens&type= -> action=query&meta=tokens&type=
 * action=query&list=recentchanges&rctoken -> action=query&meta=tokens&type=csrf
 * action=query&prop=revisions&rvtoken=rollback -> action=query&meta=tokens&type=rollback
 * action=query&meta=userinfo&uiprop=preferencestoken -> action=query&meta=tokens&type=csrf
 * action=query&list=users&ustoken=userrights -> action=query&meta=tokens&type=userrights

Languages updated in 1.37
MediaWiki supports over 350 languages. Many localisations are updated regularly. Below only new and removed languages are listed, as well as changes to languages because of Phabricator reports.


 * (T280435) LRM and RLM characters were removed from names of languages with parentheses in Names.php
 * (T283422) Add namespace name translations and change the autonym of the Kinyarwanda language to "Ikinyarwanda".
 * (T283423) Change the autonym of the Lombard language from "lumbaart" to "lombard".
 * (T279619) Added language support for Dagbani (dag).
 * (T282085) Added language support for Malay in Arabic (Jawi) script (ms-arab).
 * (T283053) Added language support for Ojibwe (ojb).
 * (T283480) Added language support for Wallisian (wls, Fakaʻuvea).
 * (T284002) Added language support for Paiwan (pwn).
 * (T284044) Added language support for Carpathian Romani (rmc).
 * (T286460) Added language support for Gun (guw, Gungbe).
 * (T287345) Added language support for Baoulé (bci).
 * (T290126) Added language support for Kildin Sami (sjd).
 * (T290408) Added language support for Pite Sami (sje).
 * (T25216) Started the renaming of the language code for Norman from nrm to nrf.

Breaking changes in 1.37

 * The Revision class, emitting deprecation warnings since 1.35, was removed entirely. As part of this, the following hooks that included a Revision object were removed:
 * ArticleRevisionUndeleted - use RevisionUndeleted
 * ArticleRollbackComplete - use RollbackComplete
 * DiffRevisionTools - use DiffTools
 * DiffViewHeader - use DifferenceEngineViewHeader
 * HistoryRevisionTools - use HistoryTools
 * NewRevisionFromEditComplete - use RevisionFromEditComplete
 * PageContentInsertComplete - use PageSaveComplete
 * PageContentSaveComplete - use PageSaveComplete
 * ParserFetchTemplate - use BeforeParserFetchTemplateRevisionRecord
 * RevisionInsertComplete - use RevisionRecordInserted
 * TitleMoveComplete - use PageMoveComplete
 * TitleMoveCompleting - use PageMoveCompleting
 * UndeleteShowRevision - no replacement
 * UserRetrieveNewTalks - no replacement
 * … the following methods and variables have been removed:
 * Article::$mRevision
 * Article::getRevisionFetched
 * ContribsPager::tryToCreateValidRevision
 * EditPage::$mBaseRevision
 * EditPage::getBaseRevision
 * LinksUpdate::getRevision
 * LinksUpdate::setRevision
 * PageArchive::getArchivedRevision
 * PageArchive::getPreviousRevision
 * PageArchive::getRevision
 * Parser::$mRevisionObject
 * Parser::fetchCurrentRevisionOfTitle
 * Parser::getRevisionObject
 * Parser::statelessFetchRevision
 * ParserOptions::getCurrentRevisionCallback
 * ParserOptions::setCurrentRevisionCallback
 * Title::countAuthorsBetween
 * Title::getFirstRevision
 * User::getNewMessageLinks
 * User::getNewMessageRevisionId
 * User::setNewtalk
 * WikiPage::getOldestRevision
 * WikiPage::getRevision
 * WikiPage::getUndoContent
 * WikiPage::updateIfNewerOn
 * … and the following methods no longer accept Revision objects as parameters:
 * CategoryMembershipChange::__construct
 * ContentHandler::getUndoContent
 * DerivedPageDataUpdater::prepareUpdate
 * DifferenceEngine::getRevisionHeader
 * Linker::buildRollbackLink
 * Linker::generateRollback
 * Linker::getRevDeleteLink
 * Linker::getRollbackEditCount
 * Linker::revComment
 * Linker::revUserLink
 * Linker::revUserTools
 * WikiPage::doDeleteUpdates
 * WikiPage::doEditUpdates
 * WikiPage::hasDifferencesOutsideMainSlot
 * WikiPage::onArticleEdit
 * WikiPage::prepareContentForEdit
 * WikiPage::updateRevisionOn
 * The following methods return arrays that formerly included a 'revision' key that would emit deprecation warnings when accessed and return a Revision object. The Revision object has been removed from the arrays, and the 'revision-record' key should be used to get the relevant RevisionRecord instead:
 * PageUpdater::doCreate
 * PageUpdater::doModify
 * Parser::statelessFetchTemplate
 * WikiPage::doEditContent
 * Finally, the ParserOptions `templateCallback` option is a callback that is called in Parser::fetchTemplateAndTitle and should return an array - the 'revision' key to that array used to be a Revision object and was used if no 'revision-record' was returned - is now ignored.
 * Previously, the classes RevisionTestModifyableContent and RevisionTestModifyableContentHandler were loaded for use in tests, but were only used within the tests for the since-removed Revision class. This content and content handler class were removed without deprecation.
 * WANObjectCache::HOLDOFF_NONE, deprecated since 1.35, was removed. Use WANObjectCache::HOLDOFF_TTL_NONE instead.
 * Calling ResourceLoader::makeVersionQuery without $modules parameter, deprecated since MediaWiki 1.34, is no longer supported.
 * LocalFile::recordUpload2, deprecated since 1.35, was removed.
 * The following methods and fields in the Language class, deprecated since 1.35, have been removed:
 * ::classFromCode
 * ::clearCaches
 * ::convertTitle
 * ::findVariantLink
 * ::$mConverter
 * ::updateConversionTable
 * The following methods in the Parser class have been removed after having been deprecated in 1.35:
 * fetchTemplate
 * Title
 * (T273354) When an edit is prevented by an 'EditFilterMergedContent' hook handler without changing the status, the edit form will now be displayed.
 * User::clearNotification, which had been deprecated in 1.35, has been removed. Use WatchlistManager::clearTitleUserNotification instead.
 * User::getNewtalk, which had been deprecated in 1.35, has been removed. Use TalkPageNotificationManager::userHasNewMessages instead.
 * The Autopromote class, deprecated since 1.35, was removed. Use UserGroupManager instead.
 * The CachedAction, SpecialCachedPage, CacheHelper, and ICacheHelper classes, all emitting deprecation warnings since 1.36, have been removed.
 * The hooks BeforeHttpsRedirect, CanIPUseHTTPS and UserRequiresHTTPS, deprecated in 1.35, were removed.
 * The TitleArrayFromResult hook, deprecated in 1.36, was removed.
 * The deprecated "es6-promise" alias ResourceLoader module has been removed. Use the "es6-polyfills" module directly intead.
 * The deprecated "mediawiki.legacy.protect" ResourceLoader module, deprecated since 1.36, has been removed. Use "mediawiki.action.protect" instead.
 * The JavaScript alias $j for references to jQuery, deprecated since 1.23, has been removed. Use $ instead.
 * The AuthenticationProvider interface and the SessionProvider class no longer extend the PSR LoggerAwareInterface concept, so they can't be typehinted as LoggerAwareInterface.
 * User::getGrantName, emitting deprecation warnings since 1.36, has been removed. Use MWGrants::grantName instead.
 * The following ApiBase methods, deprecated since 1.35, have been removed:
 * ApiBase::explodeMultiValue
 * ApiBase::parseMultiValue
 * ApiBase::validateLimit
 * ApiBase::validateTimestamp
 * The User::idCacheByName public static field was removed without deprecation. Instead of using it, get a UserIdentity by name from the UserIdentityLookup service.
 * IDatabase::upsert and IDatabase::replace now only accept a single unique key. Previously, a warning was issued if there were multiple unique keys provided.
 * The MediaWiki:Autoblock_whitelist block exemption control was moved in 1.36 to MediaWiki:Block-autoblock-exemptionlist. The backward-compatibility of reading the old MediaWiki:Autoblock_whitelist page has now been dropped.
 * The following overridable methods in File hierarchy have changed signatures:
 * File::deleteFile - now accepts UserIdentity instead of User
 * File::getDescription - now accepts Authority instead of User
 * File::userCan - now accepts Authority instead of User
 * LocalFile::deleteOldFile - now accepts UserIdentity instead of User
 * The following global methods, each deprecated since 1.36, have been removed:
 * wfAppendToArrayIfNotDefault
 * wfAcceptToPrefs
 * wfConfiguredReadOnlyReason
 * wfDebugMem
 * wfGetPrecompiledData
 * wfNegotiateType
 * The following deprecated methods of the Title class have been removed:
 * ::nameOf, deprecated in 1.36
 * ::getPreviousRevisionID, deprecated in 1.34
 * ::getNextRevisionID, deprecated in 1.34
 * ::getEarliestRevTime, deprecated in 1.35
 * UploadBase::stashFile, deprecated since 1.28, was removed.
 * wfGetRusage, deprecated since 1.35, has been removed.
 * The following CLI options were removed from tests/phpunit.php:
 * use-filebackend
 * use-jobqueue
 * use-bagostuff
 * The following options (inherited from Maintenance) were also removed:
 * conf
 * dbuser
 * dbpass
 * dbdefaultgroup
 * globals
 * memory-limit
 * profiler
 * server
 * The following options were changed to environment variables:
 * wiki => PHPUNIT_WIKI
 * use-normal-tables => PHPUNIT_USE_NORMAL_TABLES
 * use-filebackend => PHPUNIT_USE_FILEBACKEND
 * use-bagostuff => PHPUNIT_USE_BAGOSTUFF
 * use-jobqueue => PHPUNIT_USE_JOBQUEUE
 * This is so that we can use the default PHPUnit entry point (T90875).
 * The PHPUNIT_REUSE_DB / --reuse-db option was removed from the phpunit.php runner. It had been broken for at least three years already. The original use case was speeding up tests on Oracle, but Oracle support was dropped several releases ago.
 * The MediaWikiPHPUnitTest__endTestHook and MediaWikiPHPUnitTest__startTestHook PHPUnit hooks were removed. MediaWikiHooksPHPUnitExtension was also removed.
 * EntryPoint::getTextFormatters was made private without a deprecation period; it had no known external callers.
 * DatabaseBlock::chooseBlock, deprecated since 1.35, was removed.
 * SpecialPageFactory::getRestrictedPages, deprecated since 1.36, was removed.
 * SpecialBlock::validateTarget, deprecated since 1.36, was removed.
 * The PatchFileLocation trait was removed without deprecation.
 * ActorMigrationBase::getExistingActorId and ::getNewActorId, emitting deprecation warnings since 1.36, were removed.
 * Hook handlers implementing the MediaWikiServicesHook hook are now prohibited from having services injected. This is because by definition, this hook runs before the service container is fully initialized.
 * The protected property LocalFile::$metadata was removed without deprecation.
 * WatchedItem::getUser, emitting deprecation warnings since 1.36, has been removed.
 * AuthManager::singleton, emitting deprecation warnings since 1.36, has been removed.
 * The AugmentPageProps class was removed without deprecation. It had no known uses.
 * Html::infobox, deprecated since 1.36, was removed.
 * ParserOptions::__construct now requires that the first parameter is a UserIdentity object - passing `null` used to fallback to the global $wgUser but was deprecated since 1.36.
 * ParserOptions::newCanonical no longer supports the first parameter being null (or omitted entirely), which would fallback to the global $wgUser but was deprecated since 1.35.
 * The SkinTemplatePreventOtherActiveTabs hook, deprecated in 1.35, was removed entirely.
 * The SkinTemplateTabAction hook, deprecated in 1.35, was removed entirely.
 * The SkinTemplateBuildNavUrlsNav_urlsAfterPermalink hook, deprecated in 1.35, was removed entirely.
 * The SkinTemplateToolboxEndHook, deprecated in 1.35, was removed entirely.
 * The following methods of the RevisionStore class, formerly emitting deprecation warnings, were removed:
 * ::newMutableRevisionFromArray
 * ::loadRevisionFromPageId
 * ::loadRevisionFromTitle
 * ::loadRevisionFromTimestamp
 * ::listRevisionSizes
 * LogEntry::getPerformer, deprecated since 1.36, was removed along with methods in sub-classes: DatabaseLogEntry, ManualLogEntry, RCDatabaseLogEntry.
 * Skin::getRelevantUser now returns an instance of UserIdentity, and not necessarily a User object. There were no known usages in the MediaWiki ecosystem that were not satisfied with UserIdentity.
 * Direct construction of the MergeHistory class, deprecated since 1.35, is no longer supported. Use MergeHistoryFactory instead. MergeHistory::checkPermissions, deprecated since 1.36, was removed.
 * Skin::generateDebugHTML, deprecated since 1.35, was removed. Call MWDebug::getHTMLDebugLog directly.
 * The ApiTestCase class no longer interacts with the global $wgUser. Previously, the global variable was set at the start of each test, and in ApiTestCase::doApiRequest if a performer was specified $wgUser was updated to match, and if no performer was specified $wgUser was used instead. Now, $wgUser is not updated, and if no performer is specified the reusable TestUser object for the sysop is relied on. Extensions or skins that rely on the global $wgUser variable (which has been deprecated since 1.35) should instead retrieve the acting user from the relevant context source.
 * SkinTemplate::makeArticleUrlDetails, deprecated since 1.35, was removed.
 * Skin::makeNSUrl, deprecated since 1.35, was removed.
 * Skin::getRevisionId, deprecated since 1.34, was removed. Use OutputPage::getRevisionId instead.
 * Skin::isRevisionCurrent, deprecated since 1.34, was removed. Use OutputPage::isRevisionCurrent instead.
 * AbstractBlock::parseTarget, deprecated since 1.36, was removed.
 * The ArticleEditUpdates hook, deprecated since 1.35, was removed.
 * The `@stable to extend` class CentralIdLookup has received the following changes:
 * The protected ::checkAudience method now returns an Authority instead of a User instance.
 * A number of its `@stable to override` methods now accept an Authority instead of a User instance as the $audience parameter.
 * A number of methods now accept a UserIdentity instead of their User parameter.
 * The ::localUserFromCentralId method now returns UserIdentity and not necessarily a User object.
 * All extensions that extend this class or use this method were updated to be ready to the new behavior.
 * WatchedItemStoreInterface::enqueueWatchlistExpiryJob, deprecated since 1.36, was removed.
 * ResultWrapper is now abstract. It cannot be directly constructed (T286694).
 * The SecondaryDataUpdates hook, deprecated in 1.32, was removed entirely.
 * Content::getDeletionUpdates, was removed. Use ContentHandler::getDeletionUpdates instead.
 * Content::getSecondaryDataUpdates, was removed. Use ContentHandler::getSecondaryDataUpdates instead.
 * wfDiff, deprecated since 1.25, has been removed.
 * Language::$mLangObjCache, deprecated since 1.35, was removed.
 * Language::$transformData, deprecated since 1.35, was removed.
 * Language::transformUsingPairFile was marked as @internal. Its deprecated parameters are no longer supported.
 * SpecialMute::getTarget, unused outside of the SpecialMute class, was made private.
 * The Skin::setupSkinUserCss method, deprecated in 1.32, was removed. Please use skin registration instead.
 * The ResourceLoaderSkinModule `legacy`, `content` and `content-thumbnails` features were deprecated. Skins should instead select from the features listed on mw:Manual:ResourceLoaderSkinModule.
 * ParserCache::getKey and ::getEtag, deprecated since 1.36, were removed.
 * The BaseTemplateToolbox hook, deprecated since 1.35, was removed.
 * Previously a capitalize-all-nouns class was added to the body element of languages where nouns must be capitalized. This class is no longer added to the body tag and must be provided by skins.
 * The SkinTemplateOutputPageBeforeExec hook, deprecated since 1.35, was removed.
 * Calling Message::toString without a parameter, which triggered deprecation warnings since 1.36, is no longer supported. You can instead use the explicit formatting methods directly, such as Message::text and Message::escaped.
 * Article::getContentObject, deprecated since 1.32, was removed.
 * Article::delete, Article::confirmDelete and ImagePage::delete were removed. The logic responsible for building the form is being moved to DeleteAction, while the actual deletion logic will be moved to a separate service.
 * WikiImporter::debugRevisionHandler, unused and for debug only, was removed.
 * Content::preloadTransform now emits deprecation warnings. Instead, please use ContentTransformer::preloadTransform. Extensions defining a content model should override ContentHandler::preloadTransform.
 * Content::preSaveTransform now emits deprecation warnings. Instead, please use ContentTransformer::preSaveTransform instead. Extensions defining a content model should override ContentHandler::preSaveTransform.
 * Constructing WikiPage objects from Title instances that cannot exist, emitting deprecation warnings since 1.36, now throws an exception. Additionally, WikiPage now implements ProperPageIdentity, rather than just PageIdentity.
 * The Skin::bottomScripts method is deprecated. Please instead use OutputPage::getBottomScripts.
 * LinksUpdate::getTriggeringUser now returns ?UserIdentity instead of ?User.
 * The LESS mixin `.box-shadow` (from mediawiki.mixins.less), deprecated since 1.36, was removed. Use CSS property `box-shadow` unprefixed for all basic supported browsers instead.
 * The LESS mixin `.flex` now no longer tries to support the 2009 version of the Flexbox specification; support for the 2012 and modern standard versions remains unchanged.
 * The StorageAwareness::ATTR_SYNCWRITES, StorageAwareness::QOS_SYNCWRITES_*, StorageAwareness::ATTR_LOCALITY, and StorageAwareness::QOS_LOCALITY_* constants were removed.

Deprecations in 1.37

 * JobQueue::getWiki, deprecated in 1.33, now emits deprecation warnings.
 * AbstractBlock::getTargetAndType and ::getTarget now emit deprecation warnings. Use ::getTargetName and ::getTargetUserIdentity together with ::getType.
 * Passing a UserIdentity to WatchlistManager::clearAllUserNotifications and WatchlistManager::clearTitleUserNotifications is now deprecated. Pass an Authority instead.
 * Passing LinkTarget to WatchlistManager::clearTitleUserNotifications and WatchlistManager::getTitleNotificationTimestamp. Pass PageIdentity instead.
 * The User class methods ::isWatched, ::isTempWatched, ::removeWatch, and ::addWatch have been deprecated. Use corresponding methods in WatchlistManager instead.
 * Multiple WatchAction methods have been deprecated in lieu of WatchlistManager:
 * ::doWatchOrUnwatch use WatchlistManager::setWatch
 * ::doWatch -> WatchlistManager::addWatch
 * ::doUnwatch -> WatchlistManager::removeWatch
 * WatchAction::getWatchToken now emits deprecation warnings. Instead use CsrfTokenSet::getToken.
 * Action::getHookContainer has been marked as internal. Actions that require access to a hook container should have one injected instead.
 * The ::getTitle and ::setTitle methods in Parser have been deprecated. Use ::getPage and ::setPage instead.
 * Title::isWatchable has been deprecated. Use WatchlistManager::isWatchable instead.
 * Methods and classes related to the primary database, previously referred to as 'master', have been deprecated, with the new ones replacing them as follows:
 * The DBMasterPos and MySQLMasterPos classes have been respectively renamed to DBPrimaryPos and MySQLPrimaryPos.
 * LocalRepo::getMasterDB -> ::getPrimaryDB
 * ForeignDBRepo::getMasterDB -> ::getPrimaryDB
 * JobQueueDB::getMasterDB -> ::getPrimaryDB
 * ForeignDBViaLBRepo::getMasterDB -> ::getPrimaryDB
 * DBFileJournal::getMasterDB -> ::getPrimaryDB
 * ILoadBalancer::getMasterPos -> ::getPrimaryPos
 * IDatabase::getMasterPos -> ::getPrimaryPos
 * ILoadBalancer::finalizeMasterChanges -> ::finalizePrimaryChanges
 * ILoadBalancer::approveMasterChanges -> ::approvePrimaryChanges
 * ILoadBalancer::beginMasterChanges -> ::beginPrimaryChanges
 * ILBFactory::beginMasterChanges -> ::beginPrimaryChanges
 * ILoadBalancer::commitMasterChanges -> ::commitPrimaryChanges
 * ILBFactory::commitMasterChanges -> ::commitPrimaryChanges
 * IDatabase::getTopologyRootMaster -> ::getTopologyRootPrimary
 * IDatabase::masterPosWait -> ::primaryPosWait
 * ILoadBalancer::runMasterTransactionIdleCallbacks -> ::runPrimaryTransactionIdleCallbacks
 * ILoadBalancer::runMasterTransactionListenerCallbacks -> ::runPrimaryTransactionListenerCallbacks
 * ILoadBalancer::rollbackMasterChanges -> ::rollbackPrimaryChanges
 * ILBFactory::rollbackMasterChanges -> ::rollbackPrimaryChanges
 * ILoadBalancer::flushMasterSnapshots -> ::flushPrimarySnapshots
 * ILoadBalancer::hasMasterConnection -> ::hasPrimaryConnection
 * ILoadBalancer::hasMasterChanges -> ::hasPrimaryChanges
 * ILBFactory::hasMasterChanges -> ::hasPrimaryChanges
 * ILoadBalancer::lastMasterChangeTimestamp -> ::lastPrimaryChangeTimestamp
 * ILoadBalancer::hasOrMadeRecentMasterChanges -> ::hasOrMadeRecentPrimaryChanges
 * ILBFactory::hasOrMadeRecentMasterChanges -> ::hasOrMadeRecentPrimaryChanges
 * ILoadBalancer::pendingMasterChangeCallers -> ::pendingPrimaryChangeCallers
 * ILoadBalancer::forEachOpenMasterConnection -> ::forEachOpenPrimaryConnection
 * ILoadBalancer::waitForMasterPos -> ::waitForPrimaryPos
 * Database::assertIsWritableMaster -> ::assertIsWritablePrimary
 * RevDelList::reloadFromMaster -> ::reloadFromPrimary
 * ExternalStoreDB::getMaster -> ::getPrimary
 * DatabaseMysqlBase::getMasterServerInfo -> ::getPrimaryServerInfo
 * MWExceptionHandler::rollbackMasterChangesAndLog -> ::rollbackPrimaryChangesAndLog
 * wfGetLB, deprecated since 1.27, now emits deprecation warnings.
 * wfLocalFile, deprecated since 1.34, now emits deprecation warnings.
 * wfFindFile, deprecated since 1.34, now emits deprecation warnings.
 * wfIncrStats, deprecated in 1.36, now emits deprecation warnings.
 * wfCanIPUseHTTPS is now deprecated, and always returns true.
 * The UserLoadFromDatabase hook has been deprecated. It had no known uses.
 * The following methods in ApiPageSet have been deprecated:
 * ::getTitles, use ::getTargets instead.
 * ::getGoodTitles, use ::getGoodPages instead.
 * ::getMissingTitles, use ::getMissingPages instead.
 * ::getGoodAndMissingTitles, use ::getGoodAndMissingPages instead.
 * ::getRedirectTitles, use ::getRedirectTargets instead.
 * ::getSpecialTitles, use ::getSpecialPages instead.
 * The following methods from the User class, deprecated in 1.35, now each emit deprecation warnings:
 * ::getOptions
 * ::isIP
 * ::isUsableName
 * ::isCreatableName
 * ::getCanonicalName
 * ::addAutopromoteOnceGroups
 * ::getEffectiveGroups
 * ::getAutomaticGroups
 * ::getFormerGroups
 * ::getIntOption
 * ::getBoolOption
 * The following methods in User were deprecated:
 * ::idFromName - use UserIdentityLookup::getUserIdentityByName instead.
 * ::resetIdByNameCache - in tests, reset service container. No replacement needed in production code.
 * Use of ActorMigration for any table except revision, deprecated in 1.34, now emits deprecation warnings. Instead of getInsertValues, use ActorNormalization::acquireActorId. Instead of getWhere and getJoin, do your own join on the actor table.
 * DatabasePostgres::remappedTableName and its dependent constructor parameter 'keywordTableMap' are deprecated. Reserved identifiers that are used as table names should be quoted where necessary.
 * LinkCache::singleton, deprecated since 1.28, now emits deprecation warnings.
 * MessageCache::singleton, deprecated since 1.34, now emits deprecation warnings.
 * LockManagerGroup::singleton and ::destroySingletons, deprecated since 1.34, now emit deprecation warnings.
 * HtmlFileCacheUpdate::newFromTitles is now deprecated and emitting warnings. Use newFromPages instead.
 * SessionProvider ::setLogger, ::setManager, ::setConfig, and ::setHookContainer were deprecated. Use ::init to inject dependencies, or override ::postInitSetup to do any custom post-initialization configuration.
 * AbstractAuthenticationProvider ::setLogger, ::setManager, ::setConfig, and ::setHookContainer now emit deprecation warnings. Use ::init to inject dependencies, or override ::postInitSetup to do any custom post-initialization configuration.
 * User::isLoggedIn, deprecated since 1.36, now emits deprecation warnings. Use the method it wraps, User::isRegistered, instead.
 * FileBackendGroup::singleton and ::destroySingletons, deprecated since 1.35, now emit deprecation warnings.
 * The first parameter of User::getBlock should now be an integer using the Authority::FOR_XXX constants. Providing a boolean is deprecated.
 * ApiBase::addBlockInfoToStatus is deprecated for use by extensions. It is now marked as @internal and may be deleted in the future. It should not be necessary to call this method, Authority should be providing all relevant information via a PermissionStatus object.
 * JobQueueGroup::singleton was deprecated - use MediaWikiServices::getJobQueueGroup instead.
 * JobQueueGroup::destroySingletons was deprecated. JobQueueGroups are now automatically destroyed after tests.
 * LinkCache::addGoodLinkObj has been deprecated, since it is prone to corrupting the cache with invalid information. Use addGoodLinkObjFromRow instead. PHPUnit tests must use LinkCacheTestTrait::addGoodLinkObject.
 * ContentHandler::getContentText is now deprecated. Use Content::getText instead.
 * LinkCache::addLinkObj has been deprecated, use PageStore::getPageForLink instead.
 * MediaWiki\User\UserNamePrefixSearch::search previously accepted as its first parameter either the string 'public' or a UserIdentity object, to filter results for. It now expects an Authority object instead of UserIdentity, and providing just a UserIdentity will now trigger a deprecation warning.
 * User::getRights, deprecated since 1.34, now emits deprecation warnings.
 * User::changeableGroups and ::changeableByGroup now emit deprecation warnings. Use corresponding methods in UserGroupManager instead.
 * User::incEditCount was deprecated in favor of the new method UserEditTracker::incrementUserEditCount.
 * RepoGroup::singleton, ::destroySingleton and ::setSingleton, deprecated since 1.34, now emit deprecation warnings.
 * RecentChange::getPerformer, deprecated since 1.36, now emits deprecation warnings. Use ::getPerformerIdentity instead.
 * ContentHandler::cleanupHandlersCache, deprecated since 1.35, now emits deprecation warnings.
 * Category::getTitle was deprecated in favor of Category::getPage
 * File::getUser method now emits deprecation warnings, along with its overrides in LocalFile and ForeignApiFile in favor of ::getUploader.
 * SpecialBlock::checkUnblockSelf, deprecated in 1.36, now emits deprecation warnings.
 * (T284179) The mediawiki.viewport ResourceLoader module is deprecated. You can now just use MutationObserver or InterSectionObserver directly, which are widely available in all supported JavaScript browsers.
 * The following constructor options of DatabaseBlock class will now trigger deprecation warnings:
 * the 'byText' property with blocker's name,
 * the 'by' property with blocker's ID, For both of these, use the 'by' property with UserIdentity value instead.
 * The BeforeResetNotificationTimestamp hook was deprecated.
 * ArchivedFile::getUser ::getRawUser ::getRawUserText were deprecated in favor of ::getUploader. ::getRawDescription was deprecated in favor of ::getDescription with RAW audience parameter.
 * When calling LocalFile::newFromRow or LocalFile::loadFromRow, passing extra fields not requested by ::getQueryInfo will now trigger deprecation warnings. This is to warn callers that deprefixing and automatic assignment of such fields will not be done in a future version.
 * JobSpecification::getTitle was deprecated without providing a replacement. It wasn't used and job given the purpose of JobSpecification class it is not needed.
 * The protected method File::getImageSize is now deprecated.
 * BacklinkCache::get was deprecated, use BacklinkCacheFactory::getBacklinkCache instead.
 * Title::getBacklinkCache now emits deprecation warnings. Instead, use the ::getBacklinkCache method in the BacklinkCacheFactory service.
 * MediaHandler::getImageSize, ::getMetadata, and ::isMetadataValid were deprecated and should no longer be overridden. Instead, sub-classes should override getSizeAndMetadata.
 * Deprecated File::getMetadata. Instead use ::getMetadataArray, ::getMetadataItem and ::getMetadataItems.
 * Message::title has been deprecated; use Message::page instead.
 * BaseTemplate::getAfterPortlet, BaseTemplate::renderAfterPortlet, and the BaseTemplateAfterPortlet hook, which were deprecated in 1.35, now emit deprecation warnings.
 * The LocalFile::getHistory hook is deprecated.
 * Calling WikiPage::prepareContentForEdit without a UserIdentity is now deprecated.
 * User::getEditTokenObject, ::getEditToken, and ::matchEditToken were each deprecated. Use CsrfTokenRepository, which is available via IContextSource, instead. ::matchEditTokenNoSuffix was deprecated without replacement. It was introduced to be able to provide custom error message if the token was submitted, but ending slashes were stripped by some ASCII mangling proxy.  Use ::matchToken instead, such proxies are much less common now and there's not much benefit in customising the error message.
 * ContentHandler::getForTitle, deprecated since 1.35, now emits deprecation warnings.
 * User::listOptionKinds, deprecated since 1.35, now emits deprecation warnings.
 * WikiPage::doEditContent, deprecated since 1.32, now emits deprecation warnings.
 * CentralIdLookup::factory and ::factoryNonLocal now emit deprecation warnings; obtain an instance from MediaWikiServices instead.
 * The class RandomPage was renamed to SpecialRandomPage. The class RandomPage is now deprecated.
 * BotPassword::invalidateAllPasswordsForCentralId was deprecated.
 * BotPassword::removeAllPasswordsForCentralId was deprecated.
 * The Title class members: $mTextform, $mUrlform, $mDbkeyform, $mNamespace, $mInterwiki, and $mFragment have been deprecated to not be used directly. Instead, their corresponding accessor methods should be used.
 * IDatabase::fetchObject, ::fetchRow, ::numRows, ::numFields, ::fieldName, ::freeResult and ::dataSeek are deprecated. Use the corresponding methods in IResultWrapper instead.
 * ResultWrapper::unwrap, DatabaseMysqlBase::fieldType and DatabasePostgres::fieldType each now emit deprecation warnings.
 * Sub-classes implementing Database::doQuery should return either boolean or an IResultWrapper. To do otherwise will now trigger a deprecation warning.
 * User::getOptionKinds and ::resetOptions, both deprecated since 1.35, now emit deprecation warnings.
 * The following methods in MWNamespace, all deprecated since 1.34, now emit deprecation warnings:
 * ::isMovable
 * ::isSubject
 * ::getTalk
 * ::getSubject
 * ::getAssociated
 * ::equals
 * ::subjectEquals
 * ::hasTalkNamespace
 * ::wantSignatures
 * ::isWatchable
 * ::getSubjectNamespaces
 * ::getTalkNamespaces
 * ::isCapitalized
 * ::hasGenderDistinction
 * ::isNonincludable
 * ::getNamespaceContentModel
 * ::getRestrictionLevels
 * ::getCategoryLinkType
 * LogFormatter::styleRestricedElement has been deprecated in favor of LogFormatter::styleRestrictedElement
 * The following hooks related to user preferences were deprecated:
 * UserLoadOptions: use LoadUserOptions instead.
 * UserSaveOptions: use SaveUserOptions instead.
 * UserResetAllOptions: no replacement was provided, the hook is not used.
 * Title::isNamespaceProtected, deprecated in 1.34, now emits deprecation warnings.
 * UserSelectQueryBuilder::userIds, ::userNames, and ::userNamePrefix has been deprecated in favor of ::whereUserIds, ::whereUserNames, and ::whereUserNamePrefix.
 * Manually constructing a MovePage object, deprecated in 1.34, now emits deprecation warnings. Use MovePageFactory instead.
 * The following deletion-related methods were deprecated:
 * WikiPage::doDeleteArticleReal (soft) - use DeletePage
 * WikiPage::doDeleteArticleBatched (soft) - no replacement
 * WikiPage::isBatchedDelete (soft) - use DeletePage
 * WikiPage::doDeleteUpdates (hard) - no replacement
 * WikiPage::getDeletionUpdates (hard) - no replacement
 * Title::isBigDeletion (soft) - no replacement
 * Relying on PermissionManager or Authority to check for big deletions was deprecated. This is now automatically checked if you use DeletePage::deleteIfAllowed. (T288759)
 * The userCan hook now emits deprecation warnings. Use the getUserPermissionsErrors or getUserPermissionsErrorsExpensive hooks instead.
 * Parser::$mUser public access, and the methods ParserOptions::getUser and Parser::getUser each now emit deprecation warnings.
 * The following methods in the Title class have been deprecated in favor of the corresponding methods in the new RestrictionStore service (with different names where indicated):
 * ::areCascadeProtectionSourcesLoaded
 * ::areRestrictionsCascading
 * ::areRestrictionsLoaded
 * ::getAllRestrictions
 * ::getCascadeProtectionSources
 * ::getFilteredRestrictionTypes -> ::listAllRestrictionTypes
 * ::getRestrictionExpiry
 * ::getRestrictionTypes -> ::listApplicableRestrictionTypes
 * ::getRestrictions
 * ::isCascadeProtected
 * ::isProtected
 * ::isSemiProtected
 * ::loadRestrictionsFromRows
 * The following Title methods have been deprecated with no direct public replacement:
 * ::deleteTitleProtection
 * ::getTitleProtection
 * ::flushRestrictions
 * ::loadRestrictions
 * User::isAllowUsertalk now emits deprecation warnings. Use User::getBlock and AbstractBlock::isUsertalkEditAllowed instead.
 * Classes used by Preprocessor_DOM have been merged with classes used by Preprocessor_Hash, as Preprocessor_DOM was removed in 1.35.
 * PPDPart has been merged into PPDPart_Hash
 * PPDStack has been merged into PPDStack_Hash
 * PPDStackElement has been merged into PPDStackElement_Hash
 * By default, the global variable $wgUser is now an instance of the new class StubGlobalUser rather than User, and the first time it is used it will emit deprecation warnings (the $wgUser variable was deprecated in 1.35). For extensions that read from this variable, please use a relevant ContextSource instead, falling back to RequestContext::getMain if none is available.
 * Collation::singleton and ::factory were deprecated; obtain an instance of the CollationFactory from MediaWikiServices instead.
 * Title::getDefaultNamespace has been deprecated to be removed because there are no known callers/consumers.
 * With removal of the stub threshold feature, the following methods now emit deprecation warnings:
 * LinkRenderer::setStubThreshold and ::getStubThreshold - no replacement.
 * LinkRendererFactory::createForUser - calling ::create is now sufficient
 * ParserOptions::setStubThreshold and ::getStubThreshold - no replacement.
 * User::getStubThreshold - no replacement.
 * The ArticleDelete and ArticleDeleteComplete hooks were deprecated. Use PageDelete and PageDeleteComplete instead.
 * The ArticleUndeleteLogEntry hook was deprecated without replacement.
 * The following LESS mediawiki.mixins have been deprecated:
 * .box-sizing
 * .transform
 * .transform-origin
 * .transition
 * .transition-transform
 * The `UndeleteForm::undelete` hook was deprecated. A new hook was introduced, `PageUndelete`, that provides handlers with more information and is also called for non-UI requests. The capability of replacing the PageArchive object has been removed, as that violates the laws of nature.

Other changes in 1.37

 * WatchlistManager::addWatch and WatchlistManager::addWatchIgnoringRights, which replace User::addWatch, now call the WatchArticle and WatchArticleComplete hooks.
 * WatchlistManager::removeWatch and WatchlistManager::removeWatchIgnoringRights, which replace User::removeWatch, now call the UnwatchArticle and UnwatchArticleComplete hooks.
 * The overridable postInitSetup method was added to the AbstractAuthenticationProvider class. A provider can override postInitSetup to do any custom post-initialization configuration.
 * The overridable postInitSetup method was added to the SessionProvider class. A provider can override postInitSetup to do any custom post-initialization configuration.
 * The protected getConfig method was added to the SessionProvider class. Use SessionProvider::getConfig to get a config.
 * The DBAccessBase class is deprecated. Classes that used to extend it should get a load balancer (factory) injected in the constructor instead.
 * ActorNormalization::acquireActorId now requires IDatabase parameter. Not providing one emitted deprecation warnings since 1.36.
 * Anti-lock constants ALF_PRELOAD_LINK, ALF_NO_BLOCK_LOCK, ALF_NO_LINK_LOCK and ALF_PRELOAD_EXISTENCE have been removed. They're unused since 1.25.
 * (T278036) CSS class 'mw-htmlform-field-autoinfuse' used by some forms has been renamed to 'mw-htmlform-autoinfuse'.
 * User::newFromRow does not accept pre-loaded user preferences under $data['user_properties'] anymore. This optimization was not used.
 * The following files change the letter case of the file names:
 * SpecialRandompage.php -> SpecialRandomPage.php
 * SpecialRandomredirect.php -> SpecialRandomRedirect.php
 * SpecialRandomrootpage.php -> SpecialRandomRootPage.php
 * Media files which are uploaded server side using the importImages.php maintenance script will now have the "mw-server-side-upload" change tag.
 * (T284917) The stub threshold feature has been removed.
 * Skin::getPoweredBy and Skin::getCopyrightIcon have been deprecated as they are only designed for use by skins extended BaseTemplate. You can move calls to instead use BaseTemplate::getPoweredByHTML and ::getCopyrightIconHTML respectively.
 * The SkinGetPoweredBy hook is deprecated. No replacement is provided.
 * HTMLTitleTextField didn't support interwiki titles well previously. Starting with 1.37, HTMLTitleTextField has a new parameter, 'interwiki', which can be used to control acceptance of interwiki titles. To provide a transitional period, the default value ('interwiki' => null) ensures MW will have the same behavior as before (logging a deprecation warning). In 1.38, the default behavior will change to "interwiki links aren't allowed".

Compatibility
MediaWiki 1.37 requires PHP 7.3.19 or later and the following PHP extensions:


 * ctype
 * dom
 * fileinfo
 * iconv
 * intl
 * json
 * mbstring
 * xml

MySQL/MariaDB is the recommended DBMS. PostgreSQL or SQLite can also be used, but support for them is somewhat less mature.

The supported versions are:


 * MySQL 5.5.8 or later
 * PostgreSQL 9.4 or later
 * SQLite 3.8.0 or later

Online documentation
Documentation for both end-users and site administrators is available on MediaWiki.org, and is covered under the GNU Free Documentation License (except for pages that explicitly state that their contents are in the public domain):

https://www.mediawiki.org/wiki/Special:MyLanguage/Documentation

Mailing list
A mailing list is available for MediaWiki user support and discussion:

https://lists.wikimedia.org/mailman/listinfo/mediawiki-l

A low-traffic announcements-only list is also available:

https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce

It's highly recommended that you sign up for one of these lists if you're going to run a public MediaWiki, so you can be notified of security fixes.

IRC help
There's usually someone online in #mediawiki on irc.libera.chat.