path: root/RELEASE-NOTES-1.41

= MediaWiki 1.41 =

== MediaWiki 1.41.0-PRERELEASE ==

THIS IS NOT A RELEASE YET

MediaWiki 1.41 is an alpha-quality development branch, and is not recommended
for use in production.

== Upgrading notes for 1.41 ==
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 1.35.

Some specific notes for MediaWiki 1.41 upgrades are below:
* (T178356) MediaWiki now requires browsers to support ES6 for them to receive
  JavaScript, up from ES5. In practice, this primarily means that users of
  Internet Explorer 11 (EOL in 2022) will no longer get JavaScript tools.
* …

For notes on 1.40.x and older releases, see HISTORY.

=== Configuration changes for system administrators in 1.41 ===
* $wgGroupPermissions: The 'purge' permission is now considered an
  implicit right that can be rate limited, but not revoked. This has
  effectively already been the case for a long time, see T291316.

==== New configuration ====
* $wgPrivilegedGroups – Users belonging in some of the listed groups will be
  audited more aggressively.
* $wgPageLinksSchemaMigrationStage – This temporary flag lets you control the
  migration stage for converting the pagelinks database table into normal form.
* $wgExternalLinksDomainGaps – Can be used by large wikis to optimize certain
  external link queries.
* $wgResourceLoaderEnableSourceMapLinks - Add a SourceMap header to
  ResourceLoader responses for JavaScript modules (T47514).
* $wgVirtualDomainsMapping - Mapping of virtual domains to other dbs. It's
  useful to get connection to the external cluster.
* …

==== Changed configuration ====
* $wgAuthManagerAutoConfig – When using this setting to modify the
  authentication system in MediaWiki, the classes
  TemporaryPasswordPrimaryAuthenticationProvider,
  LocalPasswordPrimaryAuthenticationProvider and
  EmailNotificationSecondaryAuthenticationProvider now require
  DBLoadBalancerFactory, not DBLoadBalancer, as a service.
* $wgUseFileCache is no longer used for ResourceLoader module caching.
* $wgLBFactoryConf['secret'] has been replaced by $wgChronologyProtectorSecret.
* …

==== Removed configuration ====
* $wgCommentTempTableSchemaMigrationStage – This temporary flag did let you
  control the migration stage for the temporary comment database table, from
  revision.
* $wgExternalLinksSchemaMigrationStage – This temporary flag did let you
  control the migration stage for the externallinks database table.
* $wgParserOutputHooks - This array interacted with
  ParserOutput::addOutputHook(), which has been deprecated since 1.38 and was
  removed in this release.
* …

=== New user-facing features in 1.41 ===
* Special:RandomPage can now take multiple namespaces in its URL, split by ','.
* The aria-level HTML attribute is now allowed in wikitext by the Sanitizer.
* …

=== New features for sysadmins in 1.41 ===
* $wgDBssl can now enabled in the installer when the database type is
  Postgres or MariaDB/MySQL (T335828).
* MWHttpRequest will forward 'tracestate' and/or 'traceparent' headers when
  those are present in the original request and $wgAllowExternalReqID is set
  to true.
* MultiHttpClient will send X-Request-Id header and additionally will forward
  'tracestate' and/or 'traceparent' headers when those are present in the
  original request and $wgAllowExternalReqID is set to true.
* (T191805) The max possible size of an uploaded file was increased to 32 GiB.
* …

=== New developer features in 1.41 ===
* Added ForeignResourcesDir extension.json / skin.json attribute, which should
  point to the directory holding your foreign-resources.yaml file. See
  https://www.mediawiki.org/wiki/Foreign_resources for background.
* Added PrivilegedGroups attribute for extension.json / skin.json, which lets
  you add any new user groups you define to wgPrivilegedGroups (see above).
* Added a .gitmessage commit template. To use it, run:
  `git config commit.template .gitmessage`
* A new hook, TextSlotDiffRendererTablePrefixHook, has been added to allow
  extensions to add content within #mw-content-text but after the
  DifferenceEngineViewHeader or DifferenceEngineShowDiffPage hooks have been
  run. The new hook is used to add elements within a horizontal display area,
  where their order can be explicitly set. Examples of uses for this include
  adding the VisualEditor diff-type switch, and the legend for inline diffs that
  is displayed if Wikidiff2 is installed.
* validation callbacks for HTMLForm fields can now return Status objects.
  HTMLForm::validate will convert good Status instances to true and Status
  instances to a string containing a list with the errors.
* ?action=rollback, if successful, will fire core's postEdit JavaScript hook;
  for now, we do *not* display a success message to the user via mw.notify(),
  as the RollbackAction form's success page is already shown
* MultiHttpClient constructor will accept `headers` property which defines a
  set of headers attached to every request performed by the client.
* New `Wikimedia/Http/TelemetryHeadersInterface` interface that provides a
  telemetry information which could be attached to HTTP Requests
* Wikimedia/Http/TelemetryHeadersInterface can be passed to MultiHttpClient
  via 'telemetry' option.
* UserRegistrationLookup adds support for multiple kinds of registration dates
  Extensions providing support for wiki-farm can use this to provide a global
  registration date (across all wikis), for example.
* When $wgUseXssLanguage is set to true (enabled by default in
  DevelopmentSettings.php), ?uselang=x-xss can be used to easily test
  whether all messages are being escaped correctly.
* Html::noticeBox accepts new optional parameters, 'heading' & 'iconClassName'.
  'heading' allows to pass an string as title; 'iconClassName' overwrites the
  default info icon.
* …

=== External library changes in 1.41 ===

==== New external libraries ====
* Added pinia at v2.0.16.
* Added symfony/polyfill-php81 at v1.28.0.
* Added symfony/polyfill-php82 at v1.28.0.
* Added symfony/polyfill-php83 at v1.28.0.

===== New development-only external libraries =====
* …

==== Changed external libraries ====
* Updated codex, codex-design-tokens and codex-icons
  from v0.6.2 to v1.0.0.
* Updated guzzlehttp/guzzle from 7.5.0 to 7.5.3.
* Updated jQuery from v3.6.1 to v3.7.0.
* Updated justinrainbow/json-schema from 5.2.12 to v5.2.13.
* Updated Mustache from 3.0.1 to 4.2.0.
* Updated OOjs from 6.0.0 to 7.0.1.
* Updated OOUI from v0.46.3 to v0.48.1.
* Updated pear/mail from 1.5.0 to 1.5.1.
* Updated symfony/polyfill-php82 from v1.27.0 to v1.28.0.
* Updated symfony/yaml from v5.4.17 to v5.4.23.
* Updated wikimedia/bcp-47-code from 1.0.0 to 2.0.0.
* Updated wikimedia/common-passwords from 0.4.0 to 0.5.0.
* Updated wikimedia/composer-merge-plugin from 2.0.1 to 2.1.0.
* Updated wikimedia/html-formatter from 3.0.1 to 4.0.3.
* Updated wikimedia/ip-utils from 4.0.0 to 5.0.0.
* Updated wikimedia/less.php from 4.0.0 to 4.1.1.
* Updated wikimedia/minify from 2.3.0 to 2.5.1.
* Updated wikimedia/remex-html from 3.0.3 to 4.0.1.
* Updated wikimedia/timestamp from 4.1.0 to 4.1.1.
* Updated wikimedia/utfnormal from 3.0.2 to 4.0.0.
* …

===== Changed development-only external libraries =====
* Updated mediawiki/mediawiki-codesniffer from 41.0.0 to 42.0.0.
* Updated mediawiki/mediawiki-phan-config from 0.12.1 to 0.13.0.
* …

==== Removed external libraries ====
* jquery.hoverIntent was removed.
* codex-search was removed, it's part of codex now.
* wikimedia/ip-set was removed, it's part of wikimedia/ip-utils now.
* jquery.color was removed.
* jquery.fullscreen was removed.
* jquery.form was removed.
* …

=== Bug fixes in 1.41 ===
* …

=== Action API changes in 1.41 ===
* (T322944) `Authorization` was added to the default list of headers
  allowed for cross-origin API requests ($wgAllowedCorsHeaders).
* …

=== Action API internal changes in 1.41 ===
* …

=== Languages updated in 1.41 ===
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.

* (T345807) Added language support for Karekare (kai).
* (T333765) Removed language support for Akan (Ak).
* (T332113) Added language support for Northern Hindko (hno).
* (T333425) Added language support for Iraqi (Mesopotamian) Arabic (acm).
* (T336919) Added language support for Crimean Tatar (Romania) (crh-ro).
* (T338416) Added language support for Betawi (bew).
* (T341545) Added language support for West Coast Bajau (a.k.a. Sama; bdr).
* (T332118) Namespace translations for Angika (anp) were added
* (T341942) The autonym of the Buginese language is changed to the Latin-script
  name "Basa Ugi", and the localization in the language code "bug" is now only
  in the Latin script. It's possible to add localization in the Lontara script
  in translatewiki under the code "bug-bugi".
* (T341943) Main Page name translation was changed from "Leppa Indoë"
  to "Watangpola". If you manage a wiki in this language, make sure that
  links to the main page are correctly updated. See
  https://translatewiki.net/w/i.php?title=Support&oldid=11723654#Change_MediaWiki:Mainpage/bug

=== Breaking changes in 1.41 ===
* Article::doDelete(), deprecated since 1.37, has been removed.
* CommentStore::getStore(), deprecated since 1.31, has been removed.
* Article::getRedirectHeaderHtml() no longer accepts an array as $target.
  Passing an array was deprecated in 1.39.  (The method itself has also
  been deprecated.)
* BagOStuff::addBusyCallback(), deprecated since 1.39, has been removed.
* IExpiringStore has been removed, use either ExpirationAwareness or
  StorageAwareness constants instead.
* IDatabase::wasErrorReissuable(), deprecated since 1.40, has been removed.
* IDatabase::lastQuery and IReadableDatabase::lastQuery, deprecated in 1.40,
  have been removed.
* Database::queryMulti(), unused, has been removed without deprecation.
  The protected Database::doMultiStatementQuery method was removed, and the
  protected Database::executeQuery method signature was changed to take
  Query object as argument instead of a raw SQL string.
* Database::unionConditionPermutations(), unused, has been removed without
  deprecation.
* SimpleSearchResultSetWidget and SimpleSearchResultWidget classes, deprecated
  in 1.31, have been removed.
* Database::factory(), deprecated in 1.39, has been removed.
* Calling IDatabase::delete() or IDatabase::update() with empty conditions
  has been deprecated since 1.35. This now throws an error.
* Maintenance::shutdown() has been moved over into the MaintenanceRunner class
  without deprecation.
* The following DatabasePostgres methods were unused and have been removed:
  - ::currentSequenceValue()
  - ::triggerExists()
  - ::ruleExists()
* The following IDatabase methods were unused and removed without deprecation:
  - ::wasLockTimeout()
  - ::wasConnectionLoss()
* Database::getTempTableWrites(), previously protected, is now private.
* DatabasePostgres class parameter "keywordTableMap", deprecated since 1.37,
  has been removed.
* Database::doUpsert() and ::doReplace() have been removed without deprecation.
  Subclasses should override ::upsert() or ::replace() respectively.
* SelectQueryBuilder::lockForUpdate(), deprecated in 1.40 and unused,
  has been removed without hard deprecation.
* TransactionProfiler::setSilenced() deprecated in 1.40, has been removed.
* ILoadBalancer::closeConnection, unused, has been removed without deprecation.
* ILoadBalancer::waitFor, unused, has been removed without deprecation.
* ILBFactory::resolveDomainID and ::getChronologyProtectorTouched, unused,
  have been removed without deprecation.
* The following methods have been moved from ILoadBalancer to
  ILoadBalancerForOwner:
  - ::redefineLocalDomain()
  - ::hasPrimaryConnection()
  - ::setIndexAliases()
* LBFactory::makeCookieValueFromCPIndex() and ::getCPInfoFromCookieValue()
  has been moved to ChronologyProtector class without backward compatability
  as they are not supposed to be used outside of core.
* MWHttpRequest::factory(), deprecated since 1.34, has been removed.
* The Http class, deprecated since 1.34, with the functions ::request(),
  ::get(), ::post(), ::userAgent(), ::isValidURI(), ::getProxy(),
  ::createMultiClient() have been removed.
* WikiPage::factory(), ::newFromID() and ::newFromRow, deprecated in 1.36,
  have been removed.
* Maintenance::$mArgList, ::shouldExecute(), ::setAgentAndTriggers(),
  ::adjustMemoryLimit(), ::globals(), and ::loadSettings() have been removed.
* The GenericArrayObject class, deprecated in 1.40,
  has been removed.
* The $replace parameter has been removed from HookContainer::scopedRegister.
  This parameter was unused outside core, and the functionality was intended
  for testing.
* PrevNextNavigationRenderer class, deprecated in 1.39,
  has been removed.
* class alias MediaWiki\User\WatchlistNotificationManager, deprecated in 1.36,
  has been removed.
* MediaWikiServices::getWatchlistNotificationManager(), deprecated in 1.36,
  has been removed.
* Interface MediaWiki\Hook\ParserTestTablesHook, deprecated in 1.36,
  has been removed.
* The NewPagesLineEndingHook now takes NewPagesPager instead of
  SpecialNewpages as first argument.
* The following methods in the Title class, deprecated since 1.37, have been
  removed:
  - ::areCascadeProtectionSourcesLoaded()
  - ::areRestrictionsCascading()
  - ::areRestrictionsLoaded()
  - ::getAllRestrictions()
  - ::getCascadeProtectionSources()
  - ::getFilteredRestrictionTypes()
  - ::getRestrictionExpiry()
  - ::getRestrictionTypes()
  - ::getRestrictions()
  - ::isCascadeProtected()
  - ::isProtected()
  - ::isSemiProtected()
  - ::loadRestrictionsFromRows()
* Global function wfShowingResults, deprecated in 1.40, has been removed.
* Global function wfClearOutputBuffers, deprecated in 1.36, has been removed.
* LinkBatch::__construct() now requires that all parameters be passed. The
  fallback to MediaWikiServices emitted deprecation notices since 1.35.
* The methods IndexPager::getPagingLinks(), IndexPager::getLimitLinks() and
  IndexPager::buildPrevNextNavigation(), deprecated in 1.39,
  have been removed.
* Overriding the method IndexPager::makeLink(), deprecated in 1.39,
  is no longer possible.
* MagicWordFactory::getCacheTime() is deprecated and returns -1.
* Various mediawiki.less mediawiki.ui variables, deprecated in 1.35, have been
  removed. See also below that the remaining mediawiki.ui variables are now also
  deprecated.
* Calling getId() on an AbstractBlock from the wrong wiki, deprecated since
  1.38, now throws an exception.
* SQLite no longer supports raw MySQL queries.
* The following functions from the mediawiki.mixins Less import, deprecated
  since 1.37, have been removed: .transition(), .transition-transform(),
  .transform() and .transform-origin().
* Support was dropped for skins with paths relative to core which has been
  sending deprecation notices since 1.37. The skin `templateDirectory` key
  should now always be relative to the skin.
* The Skin public thisquery property was removed without deprecation. Only
  one skin was known to use it and that has been patched accordingly.
* The jquery.tipsy module, deprecated since 1.28, has now been removed.
* NamespaceInfo::getRestrictionLevels(), deprecated in 1.34, has been removed.
  Use PermissionManager::getNamespaceRestrictionLevels() instead.
* Proto-relative external links are now stored and indexed only as HTTPS
  instead of two rows, one for HTTP and one for HTTPS.
* MediaWikiIntegrationTestCase::getTestUser(), ::getTestSysop(), and
  ::getMutableTestUser() have been made protected and non-static.
* MediaWikiIntegrationTestCase::$supportedDBs has been changed to a private
  constant.
* MediaWikiIntegrationTestCase::addCoreDBData() has been deprecated. The method
  is now a no-op and is no longer called. Tests should create the fixtures
  they need.
* Saving preferences for a temporary user now throws an error (e.g. via
  UserOptionsManager::saveOptions)
* ApiQuery::getNamedDB() and ApiQueryBase::selectNamedDB(), deprecated in
  1.39, have been removed.
* ChangeTags::addTagsAccompanyingChangeWithChecks() and
  ChangeTags::undefineTag() unused everywhere, have been removed without
  deprecation.
* Usage of MediaWiki::preOutputCommit() with the $postCommitWork arg has been
  dropped. It's no longer used.
* SkinTemplateNavigation and SkinTemplateNavigation::SpecialPage hooks,
  deprecated in 1.39, have been removed.
* The PersonalUrls hook, deprecated in 1.39, has been removed.
* OutputPage::getCSPNonce(), soft deprecated in 1.35, now emits deprecation
  warnings.
* Support of the third parameter of LogEventsListGetExtraInputs hook,
  deprecated since 1.32, has been removed.
* JobSpecification::getTitle(), deprecated in 1.37, has been removed.
* The module mw.ui.anchor has been removed. Projects that need it should
  maintain a local copy or use the Codex link mixin. More information
  at T235961.
* ParsoidCachePrewarmJob::newSpec() now requires a PageRecord as the second
  parameter instead of a page ID.
* Public access to the DifferenceEngine properties mOldid, mNewid, mOldRev,
  mNewRev, mOldPage, mNewPage, mOldContent, mNewContent, mRevisionsLoaded,
  mTextLoaded and mCacheHit, deprecated in 1.32, was removed.
* SearchDatabase::db, deprecated since 1.38, has been removed.
* SearchDatabase::lb has been removed without deprecation, use ::dbProvider
  instead.
* StreamFile::STREAM_HEADLESS and StreamFile::STREAM_ALLOW_OB, deprecated
  in 1.34, have been removed.
* AbstractAuthenticationProvider::setLogger(), ::setManager(), ::setConfig()
  and ::setHookContainer() have been removed and also from it's related
  interface, AuthenticationProvider. The corresponding properties are set in
  AbstractAuthenticationProvider::init(). For side effects, you can override
  AbstractAuthenticationProvider::postInitSetup().
* Title::newFromTitleValue(), deprecated since 1.34, has been removed.
* Parser::OT_MSG, related to OT_MSG(3) MediaWiki constant, parameter for
  starting external parse has been dropped. This was kept since 2008 for B/C
  only and no longer used. Use instead Parser::OT_PREPROCESS as the
  replacement.
* SpecialPageAction has been removed without deprecation. There were no known
  uses outside of core.
* ConfigRepository::getValueOf() has been removed without deprecation. This
  method was introduced and never used for a long time now.
* BacklinkCache::get(), ::getLinks(), ::getCascadeProtectedLinks() which
  emitted deprecation warnings has no usage left. It has been removed.
* The following constants and methods in the Language class, hard deprecated
  since 1.40, have been removed:
  - ::ALL
  - ::SUPPORTED
  - ::MESSAGES_FALLBACKS
  - ::STRICT_FALLBACKS
  - ::factory()
  - ::isSupportedLanguage()
  - ::isWellFormedLanguageTag()
  - ::isValidCode()
  - ::isValidBuiltInCode()
  - ::isKnownLanguageTag()
  - ::getLocalisationCache()
  - ::fetchLanguageNames()
  - ::fetchLanguageName()
  - ::getConverter()
  - ::autoConvert()
  - ::autoConvertToAllVariants()
  - ::convert()
  - ::convertNamespace()
  - ::hasVariants()
  - ::hasVariant()
  - ::convertHtml()
  - ::convertCategoryKey()
  - ::getVariants()
  - ::getPreferredVariant()
  - ::getDefaultVariant()
  - ::getURLVariant()
  - ::getExtraHashOptions()
  - ::getParentLanguage()
  - ::getFileName()
  - ::getMessagesFileName()
  - ::getJsonMessagesFileName()
  - ::getFallbackFor()
  - ::getFallbacksFor()
  - ::getFallbacksIncludingSiteLanguage()
  - ::getMessagesFor()
  - ::getMessageFor()
  - ::getMessageKeysFor()
  - ::getConvRuleTitle()
* The parameter noSeparators to Language::formatNum, deprecated since 1.36,
  has been removed. Use Language::formatNumNoSeparators instead.
* The following methods in the ParserOutput class, deprecated since 1.38, have
  been removed:
  - ::addOutputHook()
  - ::addTrackingCategory()
  - ::addWarning()
  - ::getCategoryLinks()
  - ::getOutputHooks()
  - ::getProperties()
  - ::getProperty()
  - ::hasDynamicContent()
  - ::hideNewSection()
  - ::preventClickjacking()
  - ::setCategoryLinks()
  - ::setProperty()
  - ::unsetProperty()
* OutputPage::allowClickjacking() and ::preventClickjacking(), deprecated
  since 1.38, have been removed.
* ResourceFileCache has been removed without deprecation. There were no known
  uses outside of core.
* Many LocalisationCache constants, properties and methods that have no known
  usage outside of the class have been made private without deprecation.
* User::idFromName(), deprecated in 1.37, has been removed. Instead, you should
  use UserIdentityLookup::getUserIdentityByName().
* User::incEditCount(), deprecated in 1.37, has been removed. Instead, use
  UserEditTracker::incrementUserEditCount().
* Article::getTimestamp(), deprecated in 1.35, has been removed. Use WikiPage's
  or RevisionRecord's version of this method instead.
* ActionFactory::actionExists(), deprecated since 1.38, has been dropped.
* Action::exists(), deprecated since 1.38, has been dropped.
* ContentHandler::getForTitle(), deprecated since 1.35, has been dropped.
* LockManagerGroup::getDefault() and ::getAny(), deprecated since 1.35, have
  been dropped.
* BaseTemplate::getToolbox(), deprecated since 1.35, has been dropped. To add
  items to the toolbox, use the SidebarBeforeOutput hook. To get the toolbox,
  subclasses can use $this->data['sidebar']['TOOLBOX'].
* IndexPager::getHookContainer(), deprecated since 1.40, has been removed. You
  should instead inject a HookContainer into your code.
* Not specifying a manifest_version in your extension.json or skin.json file,
  deprecated since 1.26 and emitting warnings since 1.29, is no longer supported
  with a fallback; it will now have unspecified behaviour.
* RecentChange::getEngine(), deprecated since 1.29, has been removed. Use
  RCFeed::factory() instead.
* EditPage::showEditForm() no longer respects the $formCallback parameter, which
  was deprecated in 1.25. Use the EditPage::showEditForm:fields hook instead.
* The following properties in EditPage, deprecated in 1.38, were made private:
  - $mArticle
  - $mTitle
  - $isNew
  - $allowBlankArticle
  - $selfRedirect
  - $allowSelfRedirect
  - $diff
  - $undoAfter
  - $edit
  - $contentLength
* EditPage::addNewLineAtEnd(), deprecated since 1.38, was removed.
* AuthManager::checkAccountCreatePermissions(), deprecated in 1.39, has been
  removed. Use authorizeCreateAccount() or probablyCanCreateAccount() instead.
* LinkCache::addGoodLinkObj(), deprecated in 1.37, has been removed. You should
  use ::addGoodLinkObjFromRow().
* Constructing TextConflictHelper without a ContentHandlerFactory, deprecated
  since 1.35, will now trigger a type error.
* JobQueue::getWiki(), deprecated in 1.33, has been removed.
* ManualLogEntry::setTags(), deprecated in 1.33, has been removed.
* WikiPage::getDeletionUpdates(), deprecated in 1.37, has been removed.
* ResourceLoader\Context::getConfig(), deprecated in 1.34, has been removed.
* When creating a SearchUpdate instance, passing a non-Content string or Boolean
  as the $c parameter, deprecated since 1.34, will now trigger type errors.
* SkinTemplate::getNameSpaceKey(), deprecated in 1.35, has been dropped. Instead
  you should use Title::getNamespaceKey().
* The AddNewAccount hook, deprecated since 1.27, will now trigger deprecation
  warnings. You should use the LocalUserCreated hook instead.
* The PrefixSearchBackend hook, deprecated since 1.27, will now trigger
  deprecation warnings. Override SearchEngine::completionSearchBackend instead.
* PrefixSearch::validateNamespaces(), completely unused everywhere, has been
  removed without deprecation.
* BaseTemplate::getTrail() and ::printTrail(), deprecated since 1.39, have been
  dropped.
* Passing a second query parameter to Title::getFullURL(), Title::getLocalURL(),
  Title::getInternalURL(), or Title::getCanonicalURL(), each deprecated in 1.19,
  is now not supported. Pass it as a key,value pair in the first parameter array
  instead.
* Title::getBacklinkCache(), deprecated since 1.37, has been dropped. Instead,
  use BacklinkCacheFactory::getBacklinkCache().
* Title::newFromIDs and TitleFactory::newFromIDs, deprecated in 1.38, have been
  dropped; use a PageStore QueryBuilder instead.
* Title::getSelectFields(), deprecated since 1.36, has been dropped. You can use
  PageStore::newSelectQueryBuilder() instead.
* Title::getTouched() will now trigger an error if you pass it an instance of
  IDatabase rather than a READ_XXX constant. This legacy behaviour has been
  deprecated since 1.38.
* User::getGroupPermissions(), getGroupsWithPermission() & groupHasPermission(),
  all of which were deprecated since 1.34, have been removed. Instead, use the
  GroupPermissionsLookup service.
* Similarly, PermissionManager::getGroupPermissions(), getGroupsWithPermission()
  & groupHasPermission(), all of which were deprecated since 1.36, have also
  been removed. Instead, use the GroupPermissionsLookup service.
* The following old, deprecated aliases for classes in the RDBMS layer, have now
  been removed:
   - DBConnRef (use Wikimedia\Rdbms\DBConnRef)
   - Database (use Wikimedia\Rdbms\Database)
   - DatabaseBase (use Wikimedia\Rdbms\Database)
   - DatabaseMysqlBase (use Wikimedia\Rdbms\DatabaseMySQL)
   - DatabaseMysqli (use Wikimedia\Rdbms\DatabaseMySQL)
   - DatabasePostgres (use Wikimedia\Rdbms\DatabasePostgres)
   - DatabaseSqlite (use Wikimedia\Rdbms\DatabaseSqlite)
   - IDatabase (use Wikimedia\Rdbms\IDatabase)
   - FakeResultWrapper (use Wikimedia\Rdbms\FakeResultWrapper)
   - ResultWrapper (use Wikimedia\Rdbms\ResultWrapper)
* The following old, deprecated aliases for classes have now been removed:
   - MediaWiki\Rest\Handler\HtmlInputTransformHelper
   - MediaWiki\Rest\Handler\HtmlMessageOutputHelper
   - MediaWiki\Rest\Handler\HtmlOutputRendererHelper
   - MediaWiki\Rest\Handler\PageContentHelper
   - MediaWiki\Rest\Handler\PageRestHelperFactory
   - MediaWiki\Rest\Handler\ParsoidFormatHelper
   - MediaWiki\Rest\Handler\RevisionContentHelper
  (use the classes from namespace MediaWiki\Rest\Handler\Helper)
   - SearchNearMatcher (use MediaWiki\Search\TitleMatcher)
* $CHANGEDORCREATED argument of 'enotif_body' message was removed.
  It wasn't used in the default messages since 1.21.
* The AbstractBlock and DatabaseBlock public properties mExpiry, mHideName,
  mTimestamp, mAuto and mParentBlockId, deprecated since 1.34, have been
  removed.
* WikiPage::doDeleteUpdates() and ::getDeletionUpdates(), deprecated in 1.37,
  have been removed.
* The User public properties mOptions, mBlock, mBlockedby and mHideName,
  deprecated since 1.35, were removed.
* User::CHECK_USER_RIGHTS and User::IGNORE_USER_RIGHTS were removed. They were
  flags passed to methods which were previously removed.
* All public properties of LinksUpdate, deprecated in 1.38, were removed.
* The class Wikimedia\Rdbms\MySQLMasterPos, deprecated in 1.37, has been
  removed. Use Wikimedia\Rdbms\MySQLPrimaryPos instead.
* The class GetBlockErrorMessageKey, deprecated in 1.40, has been removed.
* The ability to set Parser::mTitle to null, deprecated in 1.34, was removed.
* The following MagicWord methods have been removed without deprecation. There
  were no known uses.
  - ::addToArray
  - ::compareStringLength
  - ::getVariableRegex
  - ::getVariableStartToEndRegex
  - ::getWasModified
  - ::matchStart
  - ::matchVariableStartToEnd
  - ::pregRemoveAndRecord
  - ::substituteCallback
* The following MagicWordArray methods have been removed or made private without
  deprecation. There were no known uses outside of the class.
  - ::addArray
  - ::getRegex, already marked as @internal, now private
  - ::getRegexStart, already marked as @internal, now private
  - ::getVariableRegex, deprecated since 1.36
  - ::getVariableStartToEndRegex, already marked as @internal, now private
  - ::parseMatch, now private
* AbstractContent::getRedirectChain() and ::getUltimateRedirectTarget(), both
  deprecated in 1.38, have been removed.
* The default max file size in FileBackendStore was increased from 4 GiB to
  32 GiB. Subclasses that cannot handle files larger than 4 GiB need to set
  $this->maxFileSize explicitly.
* …

=== Deprecations in 1.41 ===
* The MessageCache::get hook is deprecated for performance reasons. Use
  MessageCacheFetchOverrides instead.
* EtcdConfig::setLogger() is deprecated as it was unused and could not be
  used correctly. As a standalone class, its warnings now surface
  unconditionally via the native PHP error log.
* The interface for hook ParserModifyImageHTML have been renamed from
  ParserModifyImageHTML to ParserModifyImageHTMLHook,
  the old name is deprecated.
* (T178356) The es6-polyfills module is deprecated and is now a no-op.
* SerializedValueContainer::newUnified() is unused and now emits deprecation
  warnings.
* Profiler::setProfileID() and ::getAllowOutput() are now deprecated and also
  emit deprecation warnings. For ::setProfileID(), override the related class
  member directly in sub-class.
* (T166010) All PHP code in MediaWiki is slowly being moved to be in a class
  namespace as appropriate, so that we can use PSR-4 auto-loading, which will
  speed up general code loading of MediaWiki. The old global namespace class
  names are being left behind as deprecated aliases.

  In this release of MediaWiki, 1661 classes now have a namespace and 972 do
  not yet (63% done, up from 54% in MediaWiki 1.40.0). The following have newly
  been moved:
  - MediaWiki\Config:
    - Config
    - ConfigException
    - ConfigFactory
    - EtcdConfig
    - EtcdConfigParseError
    - GlobalVarConfig
    - HashConfig
    - MultiConfig
    - MutableConfig
    - SiteConfiguration
  - MediaWiki\EventRelayer:
    - EventRelayer
    - EventRelayerNull
    - EventRelayerGroup
  - MediaWiki\Installer:
    - Pingback
  - MediaWiki\Libs:
    - Emptiable
  - MediaWiki\Output:
    - OutputPage
    - OutputHandler
    - StreamFile
  - MediaWiki\Pager:
    - ActiveUsersPager
    - AllMessagesTablePager
    - AlphabeticPager
    - BlockListPager
    - CategoryPager
    - ContribsPager
    - DeletedContribsPager
    - HistoryPager
    - ImageListPager
    - IndexPager
    - LogPager
    - MergeHistoryPager
    - NewFilesPager
    - NewPagesPager
    - Pager
    - PagerTools
    - ProtectedPagesPager
    - ProtectedTitlesPager
    - RangeChronologicalPager
    - ReverseChronologicalPager
    - TablePager
    - UsersPager
  - MediaWiki\Parser:
    - Sanitizer
  - MediaWiki\Request:
    - ProxyLookup
    - WebRequest
  - MediaWiki\SiteStats:
    - SiteStats
    - SiteStatsInit
  - MediaWiki\Specials:
    - SpecialActiveUsers
    - SpecialAllMessages
    - SpecialAncientPages
    - SpecialApiHelp
    - SpecialApiSandbox
    - SpecialAutoblockList
    - SpecialBlankpage
    - SpecialBlock
    - SpecialBlockList
    - SpecialBookSources
    - SpecialBotPasswords
    - SpecialBrokenRedirects
    - SpecialCategories
    - SpecialChangeContentModel
    - SpecialChangeCredentials
    - SpecialChangeEmail
    - SpecialChangePassword
    - SpecialComparePages
    - SpecialConfirmEmail
    - SpecialContribute
    - SpecialContributions
    - SpecialCreateAccount
    - SpecialDeadendPages
    - SpecialDeletePage
    - SpecialDeletedContributions
    - SpecialDiff
    - SpecialDoubleRedirects
    - SpecialEditPage
    - SpecialEditTags
    - SpecialEditWatchlist
    - SpecialEmailInvalidate
    - SpecialEmailUser
    - SpecialExpandTemplates
    - SpecialExport
    - SpecialFewestRevisions
    - SpecialFileDuplicateSearch
    - SpecialFilepath
    - SpecialGoToInterwiki
    - SpecialImport
    - SpecialJavaScriptTest
    - SpecialLinkAccounts
    - SpecialLinkSearch
    - SpecialListDuplicatedFiles
    - SpecialListFiles
    - SpecialListGrants
    - SpecialListGroupRights
    - SpecialListRedirects
    - SpecialListUsers
    - SpecialLockdb
    - SpecialLog
    - SpecialLonelyPages
    - SpecialLongPages
    - SpecialMIMESearch
    - SpecialMediaStatistics
    - SpecialMergeHistory
    - SpecialMostCategories
    - SpecialMostInterwikis
    - SpecialMostLinked
    - SpecialMostLinkedCategories
    - SpecialMostLinkedTemplates
    - SpecialMostRevisions
    - SpecialMute
    - SpecialMyLanguage
    - SpecialNewFiles
    - SpecialNewPages (and capitalisation corrected)
    - SpecialNewSection
    - SpecialPageData
    - SpecialPageHistory
    - SpecialPageInfo
    - SpecialPageLanguage
    - SpecialPagesWithProp
    - SpecialPasswordPolicies
    - SpecialPasswordReset
    - SpecialPermanentLink
    - SpecialPreferences
    - SpecialPrefixIndex (and capitalisation corrected)
    - SpecialProtectedPages (and capitalisation corrected)
    - SpecialProtectedTitles (and capitalisation corrected)
    - SpecialProtectPage
    - SpecialPurge
    - SpecialRandomInCategory
    - SpecialRandom
    - SpecialRandomRedirect
    - SpecialRandomRootPage
    - SpecialRecentChanges
    - SpecialRecentChangesLinked
    - SpecialRedirect
    - SpecialRedirectToSpecial
    - SpecialRemoveCredentials
    - SpecialRenameUser (and capitalisation corrected)
    - SpecialResetTokens
    - SpecialRevisionDelete
    - SpecialRunJobs
    - SpecialSearch
    - SpecialShortPages
    - SpecialSpecialPages (and capitalisation corrected)
    - SpecialStatistics
    - SpecialTags
    - SpecialTrackingCategories
    - SpecialUnblock
    - SpecialUncategorizedCategories
    - SpecialUncategorizedImages
    - SpecialUncategorizedPages
    - SpecialUncategorizedTemplates
    - SpecialUndelete
    - SpecialUnlinkAccounts
    - SpecialUnlockdb
    - SpecialUnusedCategories
    - SpecialUnusedImages
    - SpecialUnusedTemplates
    - SpecialUnwatchedPages
    - SpecialUpload
    - SpecialUploadStash
    - SpecialUserLogin
    - SpecialUserLogout
    - SpecialVersion
    - SpecialWantedCategories
    - SpecialWantedTemplates
    - SpecialWatchlist
    - SpecialWhatLinksHere
    - SpecialWithoutInterwiki
  - MediaWiki\Specials\Redirects:
    - SpecialAllMyUploads
    - SpecialListAdmins
    - SpecialListBots
    - SpecialMycontributions
    - SpecialMylog
    - SpecialMypage
    - SpecialMytalk
    - SpecialMyuploads
  - MediaWiki\SpecialPage:
    - AuthManagerSpecialPage
    - ChangesListSpecialPage
    - DisabledSpecialPage
    - FormSpecialPage
    - ImageQueryPage
    - IncludableSpecialPage
    - LoginSignupSpecialPage
    - PageQueryPage
    - QueryPage
    - RedirectSpecialArticle
    - RedirectSpecialPage
    - SpecialPage
    - SpecialRedirectToSpecial
    - SpecialRedirectWithAction
    - UnlistedSpecialPage
    - WantedQueryPage
  - MediaWiki\Status:
    - Status
  - MediaWiki\Title:
    - ForeignTitle
    - ForeignTitleFactory
    - ImportTitleFactory
    - MalformedTitleException
    - MediaWikiTitleCodec
    - NaiveForeignTitleFactory
    - NaiveImportTitleFactory
    - NamespaceAwareForeignTitleFactory
    - NamespaceImportTitleFactory
    - NamespaceInfo
    - SubpageImportTitleFactory
    - TitleFormatter
    - TitleParser
    - TitleValue
  - MediaWiki\User:
    - BotPassword
    - ExternalUserNames
    - LoggedOutEditToken
    - PasswordReset
    - User
    - UserArray
    - UserArrayFromResult
    - UserGroupMembership
    - UserRightsProxy
  - MediaWiki\User\CentralId:
    - CentralIdLookup
    - LocalIdLookup
  - MediaWiki\Utils:
    - MWTimestamp
    - GitInfo
    - ExtensionInfo (previously under MediaWiki\ExtensionInfo)
  - Wikimedia\Rdbms:
    - ConfiguredReadOnlyMode
    - ReadOnlyMode
* Various mediawiki.ui variables have been deprecated in favor of
  'mediawiki.skin.variables.less' Codex design tokens featuring replacements.
* Hook handlers must now be specified either as a PHP callable, or as a PHP
  object that has a method matching the hook name. Other ways to specify
  the handler are deprecated and will soon be removed. Deprecated ways to
  specify a hook handler include callables wrapped in an array. Handlers
  defined using a "HookHandlers" entry in extension.json are not affected.
* TitleArray::newFromResult() has been deprecated and now emits deprecation
  warnings, use TitleArrayFromResults instead.
* The MediaWikiIntegrationTestCase::$users has been deprecated. Use Authority
  if possible, or call ::getTestUser() or ::getTestSysop() directly.
* WebRequest::isSafeRequest() and ::markAsSafeRequest() has been deprecated
  and now emits deprecation warnings. Use ::hasSafeMethod() instead.
* The tests/phpunit/phpunit.php entrypoint has been deprecated. PHPUnit
  tests should be run with composer, for example with the
  `composer phpunit:entrypoint` command.
* The unnamespace UserNamePrefixSearch class, deprecated in 1.36, now emits
  deprecation warnings. Use the MediaWiki\User\UserNamePrefixSearch service.
* The jquery.cookie ResourceLoader module has been merged into the existing
  mediawiki.cookie module; jquery.cookie remains but is deprecated.
* Passing a database to DatabaseBlockStore::insertBlock() is deprecated.
  DatabaseBlockStoreFactory should be used to fetch a correct
  DatabaseBlockStore instead.
* The global function wfGetLangObj is deprecated and emits deprecation
  warnings. Use MediaWiki\Languages\LanguageFactory::getLanguage instead.
* The SwiftVirtualRESTService class is deprecated in 1.41 and now emits
  deprecation warnings.
* SqlBagOStuff::expireAll() is deprecated and now emits deprecation warnings,
  use SqlBagOStuff::deleteObjectsExpiringBefore() instead.
* SqlBagOStuff::deleteAll() is deprecated and now emits deprecation warnings.
* Passing an actor id to the UserIdentityValue constructor is now emits
  deprecation warnings, it is deprecated since 1.36.
* UserGroupMembership::getGroupName(), deprecated in 1.38, and
  UserGroupMembership::getGroupMemberName(), deprecated in 1.40, now emit
  deprecation warnings.
* UserGroupMembership::getLink() has been deprecated in favour of
  ::getLinkHTML() and ::getLinkWiki().
* Linker::formatComment(), ::formatLinksInComment(), ::commentBlock() and
  ::revComment(), deprecated in 1.38, now emit deprecation warnings.
* PageArchive::listRevisions(), ::getRevisionRecordByTimestamp(),
  ::getArchivedRevisionRecord(), ::getPreviousRevisionRecord(),
  ::getLastRevisionId() and ::isDeleted(), deprecated in 1.38,
  now emit deprecation warnings.
* SearchResultThumbnail::getSize() has been deprecated to be dropped in the
  future as it is resource intensive and degrades performance.
* The EmailUserPermissionsErrors and UserCanSendEmail hooks have been
  deprecated in favour of the EmailUserAuthorizeSend hook.
* The EmailUser hook has been deprecated in favour of the EmailUserSendEmail
  hook.
* The InterwikiLoadPrefix hook now emits deprecation warnings. Resetting the
  $wgInterwikiCache setting instead.
* SiteConfiguration::getConfig() now emits deprecation warnings, Use ::get()
  instead.
* SiteConfiguration::extractVar() and ::extractGlobal() have been deprecated
  and also emit deprecation warnings.
* JobQueueGroup::waitForBackups() is deprecated. JobQueue::waitForBackups()
  should be used instead.
* Hooks::isRegistered(), ::getHandlers(), ::run() and ::runWithoutAbort(),
  deprecated in 1.35, now emit deprecation warnings.
* VirtualRESTService class and its subclasses now emit deprecation warnings
  in 1.41 and as a replacement we can use MultiHttpClient.
* Calling the MediaWikiServices::getVirtualRESTServiceClient() function
  which creates the VirtualRESTServiceClient now emits deprecation warnings.
* Language::getMessage and Language::getAllMessages are deprecated. Use
  LocalisationCache or MessageCache as appropriate.
* VirtualRESTService class is deprecated in 1.41 and as a replacement
  we can use MultiHttpClient.
* MediaWikiServices::getConfiguredReadOnlyMode() is deprecated. Use
  ::getReadOnlyMode() instead. ReadOnlyMode::getConfiguredReason()
  and ::isConfiguredReadOnly() has been added to support that.
* UploadBase::isThrottled() has been deprecated and is emitting deprecation
  warnings. Rate limits are enforced by UploadBase::verifyTitlePermissions(),
  since rate limit checks are now implicit in permission checks.
* JobSpecification::toSerializableArray() now emits deprecation warnings.
* The following skin methods were deprecated:
  - Skin::makeSpecialUrl (use Title or Special class instead)
  - Skin::makeSpecialUrlSubpage (use Title or Special class instead)
* mw.jqueryMsg.parser, deprecated in 1.31, now emits deprecation warnings.
* ResourceLoader (T127268): The targets system is deprecated. Modules that
  have been marked as desktop or mobile only are no longer supported and
  will send deprecation warnings.
* TextSlotDiffRenderer::setLanguage() is deprecated, and calling it will
  have no effect. Use ContentHandler::getSlotDiffRenderer(), or in subclasses,
  ContentHandler::createTextSlotDiffRenderer(), to correctly inject
  dependencies into TextSlotDiffRenderer.
* The static methods encodeJsVar() and encodeJsCall() have been moved from the
  Xml class to the more appropriate MediaWiki\Html\Html one, and the old ones
  are now deprecated.
* Some work to rename classes was done in previous releases, but the renaming
  was not noted at the time. The old aliases work for now but are deprecated;
  this is now explicitly noted:
  From 1.40:
  - Category -> MediaWiki\Category\Category
  - CategoriesRdf -> MediaWiki\Category\CategoriesRdf
  - CategoryViewer -> MediaWiki\Category\CategoryViewer
  - TrackingCategories -> MediaWiki\Category\TrackingCategories
  - CommentStore -> MediaWiki\CommentStore\CommentStore
  - CommentStoreComment -> MediaWiki\CommentStore\CommentStoreComment
  - EditPage -> MediaWiki\EditPage\EditPage
  - TemplatesOnThisPageFormatter
    -> MediaWiki\EditPage\TemplatesOnThisPageFormatter
  - LinkFilter -> MediaWiki\ExternalLinks\LinkFilter
  - AtomFeed -> MediaWiki\Feed\AtomFeed
  - ChannelFeed -> MediaWiki\Feed\ChannelFeed
  - FeedItem -> MediaWiki\Feed\FeedItem
  - FeedUtils -> MediaWiki\Feed\FeedUtils
  - RSSFeed -> MediaWiki\Feed\RSSFeed
  - Html -> MediaWiki\Html\Html
  - FormOptions -> MediaWiki\Html\FormOptions
  - HtmlHelper -> MediaWiki\Html\HtmlHelper
  - ListToggle -> MediaWiki\Html\ListToggle
  - TemplateParser -> MediaWiki\Html\TemplateParser
  - RawMessage -> MediaWiki\Language\RawMessage
  - FileDeleteForm -> MediaWiki\Page\File\FileDeleteForm
  - MergeHistory -> MediaWiki\Page\File\MergeHistory
  - MovePage -> MediaWiki\Page\File\MovePage
  - ProtectionForm -> MediaWiki\Page\File\ProtectionForm
  - MediaWiki\BadFileLookup -> MediaWiki\Page\File\BadFileLookup
  - PageProps -> MediaWiki\Page\PageProps
  - MagicWord -> MediaWiki\Parser\MagicWord
  - MagicWordArray -> MediaWiki\Parser\MagicWordArray
  - MagicWordFactory -> MediaWiki\Parser\MagicWordFactory
  - Linker -> MediaWiki\Linker\Linker
  - DummyLinker -> MediaWiki\Linker\DummyLinker
  - ForkController -> MediaWiki\Maintenance\ForkController
  - OrderedStreamingForkController
    -> MediaWiki\Maintenance\OrderedStreamingForkController
  - ContentSecurityPolicy -> MediaWiki\Request\ContentSecurityPolicy
  - DerivativeRequest -> MediaWiki\Request\DerivativeRequest
  - FauxRequest -> MediaWiki\Request\FauxRequest
  - FauxRequestUpload -> MediaWiki\Request\FauxRequestUpload
  - PathRouter -> MediaWiki\Request\PathRouter
  - WebRequestUpload -> MediaWiki\Request\WebRequestUpload
  - FauxResponse -> MediaWiki\Request\FauxResponse
  - WebResponse -> MediaWiki\Request\WebResponse
  - MediaWiki\HeaderCallback -> MediaWiki\Request\HeaderCallback
  - StubObject -> MediaWiki\StubObject\StubObject
  - DeprecatedGlobal -> MediaWiki\StubObject\DeprecatedGlobal
  - StubGlobalUser -> MediaWiki\StubObject\StubGlobalUser
  - StubUserLang -> MediaWiki\StubObject\StubUserLang
  - Title -> MediaWiki\Title\Title
  - TitleArray -> MediaWiki\Title\TitleArray
  - TitleArrayFromResult -> MediaWiki\Title\TitleArrayFromResult
  - TitleFactory -> MediaWiki\Title\TitleFactory
  - ActorMigration -> MediaWiki\User\ActorMigration
  - ActorMigrationBase -> MediaWiki\User\ActorMigrationBase
  - WikiMap -> MediaWiki\WikiMap\WikiMap
  - WikiReference -> MediaWiki\WikiMap\WikiReference
  From 1.39:
  - ResourceLoader -> MediaWiki\ResourceLoader\ResourceLoader
  From 1.29:
  - IMaintainableDatabase -> Wikimedia\Rdbms\IMaintainableDatabase
* The WebRequest::getRequestId() and WebRequest::overrideRequestId() are
  deprecated. Use methods from MediaWiki\Http\Telemetry class instead.
* The XmlJsCode wrapper class has been renamed to MediaWiki\Html\HtmlJsCode,
  and the old name is now deprecated.
* The use of non-serializable arguments to ParserOutput::addWarningMsg() has
  been deprecated and will emit deprecation warnings.
* Class UserRightsProxy, deprecated since 1.38, now emits
  deprecation warnings from its factory functions.
* MediaWiki\ResourceLoader\Module::getDeprecationInformation() is deprecated.
  Use ::getDeprecationWarning() instead.
* Passing a Message to OutputPage::setPageTitle() is deprecated.
  Use ::setPageTitleMsg() instead (which escapes HTML metacharacters).
* Passing arguments to OutputPage::prepareErrorPage() is deprecated.
  Use explicit calls to OutputPage::setPageTitleMsg() and ::setHTMLTitle()
  instead.
* Returning a string from Action::getPageTitle() is deprecated;
  return a Message instead, which will be formatted using FORMAT_ESCAPED.
* Returning a string from SpecialPage::getDescription() is deprecated;
  return a Message instead, which will be formatted using FORMAT_ESCAPED.
* MediaWiki\Block\AbstractBlock::getReason(), deprecated since 1.35, now emits
  deprecation warnings. Use ::getReasonComment() instead.
* User::getGroups(), ::addGroup(), ::removeGroup(), ::getGroupMemberships(),
  ::getAllGroups(), ::getImplicitGroups(), deprecated since 1.35, now emit
  deprecation warnings.
* The global function wfReportTime(), deprecated since 1.40, now emits
  deprecation warnings. The SkinTemplate parameter 'reporttime' is deprecated.
* RevisionStore::getQueryInfo() and RevisionFactory::getQueryInfo() have been
  deprecated. Use ::newSelectQueryBuilder() instead.
* Following methods in rdbms library have been made internal:
  - IDatabase::getLBInfo()
  - IDatabase::setLBInfo()
  - IDatabase::insert() Use InsertQueryBuilder instead.
  - IDatabase::update() Use UpdateQueryBuilder instead.
  - IDatabase::replace() Use ReplaceQueryBuilder instead.
  - IDatabase::upsert() Use InsertQueryBuilder instead.
  - IDatabase::delete() Use DeleteQueryBuilder instead.
  - IReadableDatabase::selectField() Use SelectQueryBuilder instead.
  - IReadableDatabase::selectFieldValues() Use SelectQueryBuilder instead.
  - IReadableDatabase::select() Use SelectQueryBuilder instead.
  - IReadableDatabase::selectRow() Use SelectQueryBuilder instead.
  - IReadableDatabase::estimateRowCount() Use SelectQueryBuilder instead.
  - IReadableDatabase::selectRowCount() Use SelectQueryBuilder instead.
  - ISQLPlatform::unionQueries() Use UnionQueryBuilder instead.
* The core Wikimedia\Rdbms\DatabaseMysqlBase class has been renamed to reflect
  the earlier merger of Mysqli into it; it's now Wikimedia\Rdbms\DatabaseMySQL.
* The following methods in SpecialEmailUser have been deprecated:
  - SpecialEmailUser::validateTarget(), use EmailUser::validateTarget()
  - SpecialEmailUser::getPermissionsError(), use EmailUser::canSend() or
    EmailUser::authorizeSend()
  - SpecialEmailUser::submit(), use EmailUser::sendEmailUnsafe()
* User::isBlockedFromEmailuser() has been deprecated. EmailUser::canSend()
  checks blocks amongst other things. If you only need this check, use
  User::getBlock()->appliesToRight( 'sendemail' ).
* User::canSendEmail() has been deprecated. Use EmailUser::canSend() instead.
* The following methods, previously deprecated, now emit deprecation warnings:
  - ConfigFactory::getDefaultInstance(), deprecated since 1.27
  - AbstractContent::getNativeData(), deprecated since 1.33
  - TablePager::getBody(), deprecated since 1.24
  - ContentHandler::getSlotDiffRendererInternal(), deprecated since 1.35
  - ParserOutput::getCategories(), deprecated since 1.40
  - PasswordFactory::init(), deprecated since 1.32
* WikitextContent::getRedirectTargetAndText has been deprecated, use
  WikitextContentHandler::extractRedirectTargetAndText instead.
* WikiPage::doDeleteArticleBatched, deprecated in 1.37, now emits deprecation
  warnings.
* WikiPage::getPageIsRedirectField() is now deprecated.
* WikiPage::insertRedirect() is now deprecated.
* Parser::getFreshParser(), deprecated since 1.39, now emits deprecation
  warnings.
* The legacy MediaWiki UI ResourceLoader modules, such as `mediawiki.ui`, are
  all now emitting deprecation warnings in the JavaScript console. Please use
  Codex CSS components instead.
* Article::getRedirectHeaderHtml() has been deprecated and emits deprecation
  warnings, use LinkRenderer::makeRedirectHeader() instead.
* SpecialBlock::getTargetAndType(), deprecated since 1.36, now emits deprecation
  warnings.
* ApiBase::checkTitleUserPermissions() now type-forces a PageIdentity instead of
  a LinkTarget. Passing a LinkTarget has been deprecated since 1.36.
* Passing a User to ApiBase::checkUserRightsAny() in the second parameter, which
  was deprecated in 1.36, is no longer read. Instead, it will use the request
  context's set Authority via IContextSource::getAuthority().
* Sanitizer::escapeIdReferenceList(), deprecated since 1.36, has been dropped.
* RecentChange::getPerformer(), deprecated since 1.36, has been dropped.
* SpecialPage::getLanguageConverter(), deprecated since 1.36, has been dropped.
  Use LanguageConverterFactory::getLanguageConverter() directly.
* SpecialBlock::checkUnblockSelf(), deprecated since 1.36, has been dropped. Use
  BlockPermissionChecker instead.
* DifferenceEngine::localiseLineNumbers() has been deprecated in favor of
  BaseTextDiffer::localizeLineNumbers(). Subclasses such as PhpTextDiffer may
  make this available via a ::localize() method.
* ChangeTags::modifyDisplayQuery() and ChangeTagsStore::modifyDisplayQuery()
  have been deprecated in favor of ChangeTagsStore::modifyDisplayQueryBuilder()
* Calling SpecialRandomPage::__construct without services as parameters is
  deprecated and emit deprecation warnings.
* …

=== Other changes in 1.41 ===
* ExternalLinksLookup::getExternalLinksForPage() now exists to centralize
  logic of looking up externallinks rows.
* The update script no longer accepts the --skip-compat-checks option.
* Use of the deprecated "Pragma: no-cache" HTTP response header on uncachable
  responses has been removed in favour of "Cache-Control: no-cache" (T345420).
* Type hints were added to:
   - The return value of WebRequest:: and DerivativeRequest::getSession()
   - The return value of WebRequest:: and DerivativeRequest::getIP()
   - The return value of User::getTitleKey()
   - The return value of User::getRequest()
   - The `$key` parameter to Skin::normalizeKey()
  None of the methods whose return value was updated belongs to a class
  stable to extend, and adding type hints to parameters is backwards
  compatible. Therefore, this is not considered a breaking change.
* The mergeMessageFileList script now only works for extensions and skins
  supporting extension registration (using extension.json or skin.json).
  It will no longer attempt to load PHP entry points.
* Parser will no longer fall back to $wgTitle if a null is provided as a
  Title or PageReference. To change the relevant title used for methods
  that do not offer an option to set the page, call Parser::setPage.
  This affects the methods cleanSig, getSection and replaceSection.
* …

== Compatibility ==

MediaWiki 1.41 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.