Release notes/1.39

= MediaWiki 1.39 =

MediaWiki 1.39.0-rc.0
THIS IS NOT A RELEASE YET

MediaWiki 1.39 is a pre-release testing branch, and is not recommended for use in production.

Upgrading notes for 1.39
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 1.31.

Some specific notes for MediaWiki 1.39 upgrades are below:
 * (T278139) Drop PHP 7.3 support in MediaWiki 1.39; require 7.4.3 or higher.

For notes on 1.38.x and older releases, see HISTORY.

Configuration changes for system administrators in 1.39

 * The default serialization method for file meta-data has been changed to JSON. You can revert it to PHP by setting the 'useJsonMetadata' property to false in $wgLocalFileRepo.
 * The DBO_SSL flag in $wgDBservers and $wgLBFactoryConf has been deprecated in favour of a boolean "ssl" parameter.
 * $wgMangleFlashPolicy is deprecated and is no longer functional. Users who are somehow still using Flash as a browser extension will be exposed to CSRF vulnerabilities.

New configuration

 * $wgAutoCreateTempUser – configures automatic user creation on page save.
 * $wgCopyUploadAllowOnWikiDomainConfig – Configures if administrators can use the MediaWiki:Copyupload-allowed-domains system message to define which domains can be used with the upload-by-url tool.
 * $wgLBFactoryConf['configCallback'] can be set to a callback function that returns an array with keys to update in $wgLBFactoryConf. This can be used to update the database configuration on the fly, e.g. to take replica hosts out of rotation.
 * $wgCdnMatchParameterOrder can be set to false if MediaWiki is behind a CDN that re-orders query parameters. This will make the code that matches request URLs to canonical CDN URLs insensitive to parameter order.
 * $wgMultiShardSiteStats – split site_stats across multiple rows. Only useful for very large, heavily edited wikis. (T306589)

Changed configuration

 * $wgInvalidUsernameCharacters now contains the char '>', reserved delimiter for external user names.

Removed configuration
deprecated since 1.35. Use the MW_WIKI_NAME environment variable to specifiy the name of the site to load configuration for. Using the WIKI_NAME environment variable for this purpose is deprecated. Reading old non-JSON cache entries is still supported. The setting had been deprecated since 1.36. from $wgMimeTypeExclusions. see T296430. and disabled by default. This feature was experimental, and disabled by default. was removed in this release. Most former "wikibits" functions were removed after deprecation in previous releases. The remaining functions, such as importScript, are available unconditionally. removed because it was unused. removed because it was unused.
 * $wgMultiContentRevisionSchemaMigrationStage - Migration is over, was
 * $wgWikiFarmSiteDetector – experimental setting removed without replacement.
 * $wgParserCacheUseJson - the ParserCache now always uses JSON serialization.
 * $wgAllowJavaUploads - To allow uploads of JAR files, remove application/java
 * $wgMaxRedirects has been removed. This feature never worked as intended,
 * $wgElementTiming has been removed. This feature was experimental,
 * $wgPriorityHints and $wgPriorityHintsRatio have been removed.
 * $wgIncludeLegacyJavaScript has been removed. Note that no functionality
 * $wgActorTableSchemaMigrationStage has been removed. Migration is over.
 * In $wgObjectCaches, globalKeyLB and localKeyLB are no longer supported.
 * $wgLegacySchemaConversion - This global configuration has been
 * $wgInterwikiPrefixDisplayTypes - This global configuration has been

New user-facing features in 1.39
page when they are (un)deleting a given page. `deletetalk` and `undeletetalk` options were added to the 'delete' and 'undelete' action APIs in MW 1.38. conventionally used as an escape mechanism to allow the use of `=` in unnamed template arguments. Defining Template:= to expand to something other than `=` has been deprecated since 1.36, with affected pages put into a special tracking category for migration.
 * Optional automatic user creation on page save ($wgAutoCreateTempUser)
 * Administrators now have the option to delete/undelete the associated "Talk"
 * `=` is now a wikitext built-in magic word, expanding to `=`. This is
 * (T284020) Bot passwords are now supported when using the REST API.

New developer features in 1.39
namespace to MediaWiki\Search\Hook. pre-save validations for specific JSON pages (T313254) errors on specfic actions. For instance account registration failed attempts due to a block (T306018).
 * Added optional $size param to SearchResultProvideThumbnail hook.
 * SearchResultProvideThumbnail hook interface moved from MediaWiki\Rest\Hook
 * JsonValidateSaveHook has been added to allow extensions to set additional
 * Added 'PermissionErrorAudit' hook, enabling extensions to audit permission

New external libraries

 * Added Codex v0.1.1. This replaces the now deprecated wvui library.

New development-only external libraries

 * Updated QUnit from 2.18.0 to 2.18.2.

Changed external libraries

 * Updated jQuery from v3.6.0 to v3.6.1.
 * Updated OOUI from v0.43.2 to v0.44.3.
 * Updated composer/semver from 3.2.6 to 3.3.2.
 * Updated symfony/polyfill-php73 from 1.25.0 to 1.26.0.
 * Updated symfony/polyfill-php80 from 1.25.0 to 1.26.0.
 * Updated symfony/yaml from 5.4.3 to 5.4.10.
 * Updated vue/compat from 3.2.23 to 3.2.37.
 * Updated wikimedia/base-convert from 2.0.1 to 2.0.2.
 * Updated wikimedia/ip-set from 3.0.0 to 3.1.0.
 * Updated wikimedia/minify from 2.2.6 to 2.3.0.
 * Updated wikimedia/php-session-serializer from 2.0.0 to 2.0.1.
 * Updated wikimedia/running-stat from 1.2.1 to 2.1.0.
 * Updated wikimedia/scoped-callback from 3.0.0 to 4.0.0.
 * Updated wikimedia/services from 2.0.1 to 3.0.0.
 * Updated wikimedia/timestamp from 3.0.0 to 4.0.0.
 * Updated wikimedia/xmp-reader from 0.8.1 to 0.8.3.

Changed development-only external libraries

 * Updated composer/spdx-licenses from 1.5.5 to 1.5.6.
 * Updated doctrine/dbal for PHP < 7.3 from 2.13.6 to 2.13.9.
 * Updated doctrine/dbal for PHP >= 7.3 from 3.1.5 to 3.4.2.

Bug fixes in 1.39
specified in extension.json files. While this setting can still be used to rename extension-defined namespaces, system administrators may need to run namespaceDupes.php after upgrading.
 * (T314013) $wgExtraNamespaces no longer overrides canonical namespace names

Action API changes in 1.39
all revisions of the associated talk page.
 * New `undeletetalk` parameter on action=undelete that allows you to restore

Languages updated in 1.39
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.

in Names.php and even used for a Wikipedia: and the "File" namespace is now "Faili". The old name of the "File" namespace was "Picha", and it's kept for backwards compatibility. If you manage a wiki in Swahili, and you use "Faili:" as a namespace anywhere in wikitext, and you mean to use it as "Media:", these need to be replaced to "Media:". ones are retained as aliases for backwards compatibility. and sr-el to sr-cyrl and sr-latn.
 * Actual localization was added for several languages, which were already
 * (T313200) Added language support for Rundi (Kirundi, rn).
 * (T310976) Added language support for Tumbuka (ChiTumbuka, tum).
 * (T314270) Added language support for Kanuri (kr).
 * (T313199) Added language support for Sylheti (syl).
 * (T311975) Added language support for Ghanaian Pidgin (gpe).
 * (T307080) Added language support for Okinawan (ryu).
 * (T307887) Added language support for Mooré (mos).
 * (T308813) Added language support for Nigerian Pidgin (pcm).
 * (T309763) Added language support for Tai Nüa (tdd).
 * (T310040) Added language support for Fante (fat).
 * (T311034) Added language support for Campidanese Sardinian (sro).
 * (T315406) Fix the autonym of the Iñupiaq language to "Iñupiatun".
 * (T315677) Removed French fallback from the Fula language (ff).
 * (T304920) In Swahili, The "Media" namespace is now "Media", as in English,
 * (T309866) Some namespace translations were updated for Kyrgyz (ky). The old
 * (T117845) Started the renaming of the language codes for Serbian from sr-ec

Breaking changes in 1.39
9-10, Firefox 27-38, and Android 4.3-4.4. - ::fetchObject - ::fetchRow - ::numRows - ::freeResult BlockRestrictionStoreFactory should be used to fetch a correct BlockRestrictionStore instead. This was deprecated since 1.38. can use ObjectCache::getInstance instead. You can use ObjectCache::getLocalClusterInstance instead. fallback to MediaWikiServices emitted deprecation notices since 1.37. provided. Not providing one has been deprecated since 1.37. override isKnownStatementRollbackError instead. override isQueryTimeoutError instead. - Linker::setStubThreshold, ::getStubThreshold. - LinkRendererFactory::createForUser. - ParserOptions::getStubThreshold, ::setStubThreshold. - The mediawiki.viewport module, deprecated in 1.37 has been removed. Use IntersectionObserver instead. and you mean to use it as "Media:", replace it with "Media:". See T304920. - Skin::getCopyrightIcon, ::getPoweredBy, deprecated in 1.37 have been removed. - Skin::bottomScripts soft deprecated in 1.37, was hard deprecated. Skins using SkinTemplate must set bodyOnly as a skin option and remove lines of code generating html, body and head elements. - Skin::makeSearchButton and Skin::makeSearchInput were deprecated in 1.38. Use SkinTemplate methods with the same name or Skin::getTemplateData instead. - Styles for the HTML classes `warningbox`, `errorbox` and `successbox` have been removed in favor of Html class methods. - The feature `legacy` used inside ResourceLoaderSkinModule, deprecated in 1.37, will no longer ship any styles. - Skin::getSkinStylePath, deprecated since 1.36, has been removed. - Skin::getPortletData has been made private. - SkinTemplate::getPersonalToolsList, deprecated in 1.35 has been removed. - The following SkinTemplate template data, deprecated in 1.37, have been removed: - poweredbyico - copyrightico - The following hooks, deprecated in 1.37, have been removed: - SkinGetPoweredBy: SkinGetPoweredByHook - The following hooks are deprecated and replaced with SkinTemplateNavigation::Universal: - SkinTemplateNavigation::SpecialPage - SkinTemplateNavigation - PersonalUrls - The mediawiki.skinning.content.externallinks module, which was deprecated in 1.36 has been removed. Skins that still rely on it   will lose the icon styling of external links by type. within a wiki farm based on the requested domain has been removed. Use the MW_WIKI_NAME environment variable to specify the name of the site to load configuration for. Using the WIKI_NAME environment variable for this purpose is deprecated. This is only relevant if you have been using $wgWikiFarmSettingsDirectory to load wiki farm config. arguments added. This method is intended for use in bootstrap code and is unused in known extensions. This method was apparently only public for testing and is unused in known extensions. since 1.36, now throws an exception. deprecation and without replacement. They had been introduced in 1.35 for use in the testing framework, and were not in use by any known extension: - exportAutoloadClassesAndNamespaces - exportTestAutoloadClassesAndNamespaces NamespaceInfo service instead. use FallbackContent and FallbackContentHandler instead. it implements. fetchObject has the same behavior as next used to. 'autocomplete-messages', which were deprecated in MediaWiki 1.29, were removed. Instead, use 'autocomplete-data' and 'autocomplete-data-messages'. MediaWikiServices::getInstance->getParser instead. given null. Previously it did nothing if given null. is now null instead of ''. have been removed. is now required. has been removed. Classes are IncompleteRevisionException, MutableRevisionRecord, MutableRevisionSlots, RevisionAccessException, RevisionArchiveRecord, RevisionFactory, RevisionLookup, RevisionRecord, RevisionSlots, RevisionStore, RevisionStoreRecord, SlotRecord, and SuppressedDataException. 1.38, now throws an exception. or TemplatesOnThisPageFormatter::format is no longer supported, a MediaWiki\Page\PageIdentity is required. TrivialLanguageConverter instead. ApiQueryUserContribs instead. removed, use MediaWiki\SpecialPage\SpecialPageFactory instead. - mediawiki.skinning.elements - mediawiki.skinning.content - mediawiki.toc.styles - mediawiki.legacy.config - mediawiki.legacy.shared - mediawiki.legacy.commonPrint ::compileLessString instead. removed. Use ::styleRestrictedElement instead. is not supported anymore. It is recommended to request an instance from the service container. removed. Use ApiQueryBlockInfoTrait instead. Use ::parsePrefixedTitlePart instead. ExternalStoreDB::getReplica instead. SpecialWatchlist::checkStructuredFilterUiEnabled now support UserIdentity as the only argument. Passing Config argument was deprecated in 1.34. ::ifTableNotExists instead. to allow passing bool true as a dbDomain, this is no longer possible, because that is an invalid value for a dbDomain. internal in 1.35. ::isTargetMuted instead. Use MediaWiki\ExtensionInfo::getAuthorsFileName. Use MediaWiki\ExtensionInfo::getLicenseFileNames. in 1.35, have been removed. removed. - ::implicitOrderby - ::selectSQLText - ::bitNot - ::bitAnd - ::bitOr - ::buildConcat - ::buildGreatest - ::buildLeast - ::buildSubstring - ::buildStringCast - ::buildIntegerCast - ::tableName - ::addIdentifierQuotes - ::buildLike - ::limitResult - ::unionSupportsOrderAndLimit - ::unionQueries - ::conditional - ::strreplace - ::timestamp - ::getInfinity - ::setTableAliases - ::setIndexAliases - ::buildGroupConcatField UnblockUser instead. not used outside core. Users should override corresponding methods in SQLPlatform instead: - Database::doInsert -> SQLPlatform::insertSqlText - Database::doDropTable -> SQLPlatform::dropTableSqlText - Database::doRollback -> SQLPlatform::rollbackSqlText - Database::doSavepoint -> SQLPlatform::savepointSqlText - Database::doReleaseSavepoint -> SQLPlatform::releaseSavepointSqlText - Database::doRollbackToSavepoint -> SQLPlatform::rollbackToSavepointSqlText deprecation as they are not used outside core. Users should call corresponding methods in SQLPlatform: - Database::makeInsertLists -> SQLPlatform::makeInsertLists - Database::isFlagInOptions -> SQLPlatform::isFlagInOptions - Database::normalizeOptions -> SQLPlatform::normalizeOptions - Database::fieldNameWithAlias -> SQLPlatform::fieldNameWithAlias - Database::isTransactableQuery -> SQLPlatform::isTransactableQuery $wgExtraNamespaces. Extensions should use the NamespaceInfo service instead of accessing this configuration setting directly. - ParserGetVariableValueVarCache: ParserGetVariableValueVarCacheHook no longer used; non-standard use of this parameter has been deprecated since 1.35. - IDatabase::fieldExists -> IMaintainableDatabase::fieldExists - IDatabase::indexExists -> IMaintainableDatabase::indexExists - IDatabase::tableExists -> IMaintainableDatabase::tableExists Only parameters for getting connection should be provided.
 * Basic non-JavaScript (Grade C) support has been dropped for Internet Explorer
 * The following methods, deprecated since 1.37, have been removed from IDatabase
 * Title::getDefaultNamespace, deprecated since 1.37, has been removed.
 * The DBPrimaryPos class alias 'DBMasterPos' has been removed.
 * The global function wfGetLB, deprecated since 1.27, has been removed.
 * Passing a db to BlockRestrictionStore::loadByBlockId is no longer supported.
 * The global function wfGetCache, deprecated since 1.32, has been removed. You
 * The global function wfGetMainCache, deprecated since 1.32, has been removed.
 * MovePage::__construct now requires that all parameters be passed. The
 * WikiPage::doEditContent, deprecated since 1.32, was removed.
 * WikiPage::prepareContentForEdit now requires a UserIdentity parameter to be
 * EventRelayerKafka, deprecated in 1.38, was removed.
 * MediaWiki\Logger\Monolog\KafkaHandler, deprecated in 1.38, was removed.
 * The "trace" option of SectionProfiler, deprecated in 1.38, was removed.
 * The global function wfWikiID, deprecated since 1.35, has been removed.
 * Database::wasKnownStatementRollbackError was removed. Subclasses should
 * Database::wasQueryTimeoutError was removed. Subclasses should
 * Database::buildSuperlative has been removed without deprecation.
 * The following methods, deprecated in 1.37, have been removed:
 * Changes to ResourceLoader modules:
 * If you manage a wiki in Swahili, and you use "Faili:" as a namespace anywhere,
 * Changes to skins:
 * Experimental wiki farm support: Automatic detection of the requested site
 * MWExceptionHandler::installHandler was marked @internal and had required
 * MWException::useOutputPage was made private without deprecation.
 * Calling getId on a User or UserIdentityValue from the wrong wiki, deprecated
 * The following methods have been removed from ExtensionRegistry without
 * The MWNamespace class, deprecated since 1.34, has been removed. Use the
 * The UnknownContent and UnknownContentHandler class aliases have been removed,
 * IResultWrapper::next now returns void, to match the Iterator interface that
 * In HTMLForm HTMLAutoCompleteSelectFields, the parameters 'autocomplete' and
 * The global $wgParser, deprecated in 1.32, was removed. Use
 * ParserOutput::setText will now set the ParserOutput's text to null if
 * The default value for the first argument to the ParserOutput constructor
 * IDatabase::lockTables and IDatabase::unlockTables, deprecated since 1.38,
 * The $context parameter to `new HTMLForm( … )` and `HTMLForm::factory( … )`
 * The class alias for revision related classes in namespace MediaWiki\Storage
 * Calling getBy on an AbstractBlock from the wrong wiki, deprecated since
 * Passing a MediaWiki\Linker\LinkTarget to EditPage::makeTemplatesOnThisPageList
 * The deprecated class alias FakeConverter has been removed, use
 * The deprecated ApiQueryContributions class alias has been removed, use
 * The deprecated MediaWiki\Special\SpecialPageFactory class alias has been
 * The following skin modules, deprecated in 1.37, have been removed:
 * FileModule::compileLessFile, deprecated since 1.35, has been removed. Use
 * LogFormatter::styleRestricedElement, deprecated since 1.37, has been
 * Title::isNamespaceProtected, deprecated in 1.34, has been removed.
 * ApiStashEdit::parseAndStash, deprecated in 1.34, has been removed.
 * LinkCache::forUpdate, deprecated in 1.34, has been removed.
 * Passing null instead of a NamespaceInfo instance to LinkCache::__construct
 * ApiQueryBase::showHiddenUsersAddBlockInfo, deprecated in 1.34, has been
 * ApiQueryBase::prefixedTitlePartToKey, deprecated in 1.35, has been removed.
 * ExternalStoreDB::getSlave, deprecated in 1.34, has been removed. Use
 * ChangesListSpecialPage::checkStructuredFilterUiEnabled and
 * DatabaseUpdater::ifNoActorTable, deprecated in 1.35, has been removed. Use
 * MediaWiki\Revision\RevisionStoreFactory::getRevisionStore was documented
 * LinkHolderArray::__construct had its signature changed. The class was marked
 * SpecialMute::isTargetBlacklisted, deprecated in 1.35, has been removed. Use
 * WebRequest::checkUrlExtension, deprecated in 1.35, has been removed.
 * ContentHandler::cleanupHandlersCache, deprecated in 1.35, has been removed.
 * SpecialVersion::getExtAuthorsFileName, deprecated in 1.35, has been removed.
 * SpecialVersion::getExtLicenseFileName, deprecated in 1.35, has been removed.
 * CategoryPage::getCategoryViewerClass and ::setCategoryViewerClass, deprecated
 * SqlBlobStore::getLegacyEncodingConversionLang, deprecated in 1.34, has been
 * wfCanIPUseHTTPS, deprecated in 1.37, has been removed.
 * wfGetScriptUrl, deprecated in 1.35, has been removed.
 * The following methods of Database class, are no longer stable to override:
 * SpecialUnblock::processUnblock, deprecated in 1.36, has been removed. Use
 * wfLocalFile and wfFindFile, deprecated in 1.34, have been removed.
 * Maintenance script resetUserTokens.php, deprecated in 1.27, has been removed.
 * These methods in Database have been removed without deprecation as they are
 * The following protected methods of Database class have been removed without
 * $wgCanonicalNamespaceNames no longer includes custom namespaces defined using
 * The following hook, deprecated in 1.35, has been removed:
 * The $variableCache parameter to the ParserGetVariableValueSwitch hook is
 * These methods have been moved from IDatabase to IMaintainableDatabase:
 * DBConnRef doesn't accept live connection in constructor anymore.
 * IDatabase::getTopologyRootPrimary was removed.
 * User::blockedBy, deprecated since 1.38, has been removed.
 * User::getBlockId, deprecated since 1.38, has been removed.

Deprecations in 1.39
LoadBalancer::getConnection instead. is hard deprecated. the ::factory method. AuthManager::authorizeCreateAccount or AuthManager::probablyCanCreateAccount instead. PageStore::newSelectQueryBuilder warnings. Use ::newFromLinkTarget instead. should use ExtensionProcessor instead. ExtensionProcessor::getExtraAutoloaderPaths have been deprecated, use get getExtractedAutoloadInfo instead. methods. - wfExpandUrl -> UrlUtils::expand - wfGetServerUrl -> UrlUtils::getServer - wfAssembleUrl -> UrlUtils::assemble - wfRemoveDotSegments -> UrlUtils::removeDotSegments - wfUrlProtocols -> UrlUtils::validProtocols - wfUrlProtocolsWithoutProtRel -> UrlUtils::validAbsoluteProtocols - wfParseUrl -> UrlUtils::parse - wfExpandIRI -> UrlUtils::expandIRI - wfMatchesDomainList -> UrlUtils::matchesDomainList These methods are exact replacements except that 1) they return null instead of false or empty string on error (where applicable); 2) UrlUtils::validProtocols does not take a parameter (documentation said not     to pass one to wfUrlProtocols anyway); 3) they use type hints (don't try passing null instead of string, etc.). config settings, use MainConfigSchema::listDefaultValues or  MainConfigSchema::getDefaultValue.  AbstractContent::getUltimateRedirectTarget are now emitting deprecation  warnings (T296430).  should be overridden.  deprecation warnings. Use MediaWikiServices::getInstance->getJobRunner  instead.  deprecated. Supply a single redirect target instead (T296430).  - .animation  - .animation-delay  - .transform-rotate  Use UserOptionsLookup::getOption instead.  are deprecated without replacement.  MediaWiki\ResourceLoader namespace, the old names becoming deprecated aliases:  ResourceLoader, MessageBlobStore, VueComponentParser.  moved to the MediaWiki\ResourceLoader namespace, the old names becoming  deprecated aliases: DerivativeResourceLoaderContext,  ResourceLoaderCircularDependencyError, ResourceLoaderClientHtml, ResourceLoaderCodexModule, ResourceLoaderContext, ResourceLoaderFileModule, ResourceLoaderFilePath, ResourceLoaderForeignApiModule, ResourceLoaderImage, ResourceLoaderImageModule, ResourceLoaderLanguageDataModule, ResourceLoaderLessVarFileModule, ResourceLoaderModule, ResourceLoaderMwUrlModule, ResourceLoaderOOUIFileModule, ResourceLoaderOOUIIconPackModule, ResourceLoaderOOUIImageModule, ResourceLoaderOOUIModule, ResourceLoaderSiteModule, ResourceLoaderSiteStylesModule, ResourceLoaderSkinModule, ResourceLoaderStartUpModule, ResourceLoaderUserModule, ResourceLoaderUserOptionsModule, ResourceLoaderUserStylesModule, ResourceLoaderWikiModule. ImportableUploadRevision and ImportableOldRevision are deprecated: - ::getUserObj → ::getUser - ::setUserObj → ::setUsername - ::setUserIP → ::setUsername warnings. warnings, use CoreParserFunctions::namespace instead. AbstractBlock::$mHideName, AbstractBlock::$mTimestamp, DatabaseBlock::$mAuto, and DatabaseBlock::$mParentBlockId, deprecated in 1.34, now emits deprecation warnings. User::$mHideName, deprecated in 1.35, now emits deprecation warnings. emit deprecation warnings. warnings. emit deprecation warnings. 1.31, now emits deprecation warnings. 1.29, now emits deprecation warnings. DerivativeContext::getStats, deprecated in 1.27, now emit deprecation warnings. warnings. warnings. deprecation warnings. warnings. warnings. are now emitting deprecation warnings: - getValidGrants - getRightsByGrant - grantName - grantNames - getGrantRights - grantsAreValid - getGrantGroups - getHiddenGrants - getGrantsLink - getGrantsWikiText warnings. warnings. None of the tableName* functions should be used by most users; if you absolutely must use raw SQL, write several tableName calls instead. LanguageCode::isWellFormedLanguageTag. the new PagerNavigationBuilder one. IndexPager::buildPrevNextNavigation have been deprecated in favor of IndexPager::getNavigationBuilder.
 * PageProps::getInstance, deprecated since 1.38, emits deprecations warnings.
 * The global function wfGetDB has been deprecated. Use
 * SpecialRedirectWithAction::__construct without SearchEngineFactory argument
 * Use of the SiteStatsUpdate constructor has been deprecated in favor of
 * AuthManager::checkAccountCreatePermissions has been deprecated. Use
 * Title::getSelectFields has been deprecated in favor of
 * Title::newFromTitleValue, deprecated since in 1.34, now emits deprecation
 * ExtensionRegistry::readFromQueue has been marked @internal. Extensions
 * Processor::getExtraAutoloaderPaths and
 * The following global functions are deprecated in favor of the listed UrlUtils
 * MaintainableDBConnRef is deprecated, use DBConnRef instead.
 * Loading DefaultSettings.php is deprecated. To get default values of main
 * AbstractContent::getRedirectChain and
 * (T244138) QueryPage::getSQL is deprecated. Instead QueryPage::getQueryInfo
 * Calling new JobRunner directly without $serviceOptions now emits
 * Passing an array of targets to Article::getRedirectHeaderHtml is
 * The following Less mediawiki.mixins have been deprecated:
 * Skin::getAction is deprecated. Use IContextSource::getActionName instead.
 * User::getOption, deprecated since 1.35, now emits deprecation warnings.
 * ILBFactory::forEachLB is deprecated. Use ::getAllLBs.
 * LoadBalancer::forEachOpenConnection and ::forEachOpenPrimaryConnection
 * The following classes were moved from the root namespace to the
 * The following classes had the "ResourceLoader" prefix stripped while being
 * The following methods in WikiRevision and their interfaces
 * ObjectCache::addBusyCallback is deprecated and non-functional.
 * MWTimestamp::getHumanTimestamp, deprecated in 1.26, now emits deprecation
 * Article::viewRedirect, deprecated in 1.30, now emits deprecation warnings.
 * Parser::getFreshParser is deprecated, use ParserFactory::getInstance.
 * CoreParserFunctions::mwnamespace is deprecated and emits deprecation
 * Registering magic variables whose names include a colon is deprecated.
 * User::blockedFor, deprecated in 1.35, now emits deprecation warnings.
 * Access to previously public properties AbstractBlock::$mExpiry,
 * Access to previously public properties User::$mBlock, User::$mBlockedby, and
 * JobQueueGroup::singleton and ::destroySingletons, deprecated in 1.37, now
 * Title::getNotificationTimestamp, deprecated in 1.35, now emits deprecation
 * Global functions wfReadOnly and wfReadOnlyReason, deprecated in 1.38, now
 * Overriding or calling DifferenceEngine::getDiffBodyCacheKey, deprecated in
 * Access to previously public property WikiRevision::$fileIsTemp, deprecated in
 * wfQueriesMustScale has been deprecated and emits deprecation warnings.
 * ContextSource::getStats, RequestContext::getStats, and
 * ManualLogEntry::setTags, deprecated in 1.33, now emits deprecation warnings.
 * WikiRevision::downloadSource, deprecated in 1.31, now emits deprecation
 * DifferenceEngine::textDiff, deprecated in 1.32, now emits deprecation
 * FormatMetadata::flattenArrayContentLang, deprecated in 1.36, now emits
 * SkinTemplate::getNameSpaceKey, deprecated in 1.35, now emits deprecation
 * EnqueueJob::newFromJobsByWiki, deprecated in 1.33, now emits deprecation
 * The following methods of the MWGrants class, all deprecated since 1.38,
 * DataUpdate::runUpdates, deprecated in 1.28, now emits deprecation warnings.
 * CdnCacheUpdate::newFromTitles, deprecated in 1.35, now emits deprecation
 * Instantiating HTMLCacheUpdate class, deprecated in 1.34, now emits deprecation
 * ISQLPlatform::tableNames (implemented by IDatabase) is soft deprecated.
 * Language::isWellFormedLanguageTag has been deprecated in favor of
 * The PrevNextNavigationRenderer helper class has been deprecated in favor of
 * The methods IndexPager::getPagingLinks, IndexPager::getLimitLinks and
 * Overriding the method IndexPager::makeLink has been deprecated.

Other changes in 1.39
are run. This way, extensions have a complete view of config variables, with all defaults applied. For example, when the default value of X used to be static but becomes dynamic, and an extension reads the value of X in the registration callback, it will now continue to function as expected. In some cases however, this may cause an undesired change in behavior: if the dynamic default of setting X depends on the value of setting Y, and an extension changes Y, the changed value of Y will no longer affect the value of X.
 * Dynamic default values are now applied before extension registration callbacks

Compatibility
MediaWiki 1.39 requires PHP 7.4.3 or later and the following PHP extensions:


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

MariaDB is the recommended database software. MySQL, PostgreSQL, or SQLite can be used instead, but support for them is somewhat less mature.

The supported versions are:


 * MariaDB 10.3 or higher
 * MySQL 5.7.0 or higher
 * PostgreSQL 10 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.