MediaWiki 1.33

MediaWiki 1.33 is a future release of MediaWiki. Consult the file for the full list of changes. It was deployed on Wikimedia Foundation wikis through incremental "wmf" alpha branches from 23 October 2018 until 10 April 2019. The 1.33.0 stable release is expected to come out on sometime in July 2019. Download or checkout the   branch in Git to follow this release.

Upgrading notes for 1.33
1.33 has several database changes since 1.32, and will not work without schema updates. Note that due to changes to some very large tables like the revision table, the schema update may take quite long (minutes on a medium sized site, many hours on a large site).

Don't forget to always back up your database before upgrading!

See the file UPGRADE for more detailed upgrade instructions, including important information when upgrading from versions prior to 1.11.

Some specific notes for MediaWiki 1.33 upgrades are below:

refreshExternallinksIndex.php) is run. These include searches for links using IP addresses, internationalized domain names, and possibly mailto links.  run your wiki with $wgActorTableSchemaMigrationStage SCHEMA_COMPAT_READ_OLD,  note that log_search rows needed to find revision deletions by target user  were incorrectly deleted. See T215464 for details.  $wgActorTableSchemaMigrationStage SCHEMA_COMPAT_WRITE_BOTH and without  migrateActors.php having been run, the log_search table may contain rows with  empty values for "target_author_actor" which will prevent log searches for  revision deletions by target user from finding those log entries. These rows  may be corrected by (re-)running migrateActors.php.
 * Some external link searches will not work correctly until update.php (or
 * If you ran migrateActors.php using an older version of MediaWiki and want to
 * If revision deletions were performed when the wiki was configured with

For notes on 1.32.x and older releases, see HISTORY.

Changes since MediaWiki 1.33.0-rc.0
tables.
 * (T225558) Update installer link to PHP intl.
 * (T225901) Only attempt to deduplicate if there is data in archive and revision
 * (T225564) Fetch tag ID before calling undefineTag.
 * (T225496) Detect APC for MainCacheType in CLI installer.
 * Call unpack with correct parameters in MimeAnalyzer.php for PHP 7.0 support.
 * (T212613) Style change tags correctly on Special:Newpages.
 * (T202211) Fix SQLite patch-(page|template)links-fix-pk.sql column order.

New configuration
accounts with block permissions the ability to block users, IPs, and IP ranges from editing specific pages, while allowing them to edit the rest of the wiki. It is a temporary setting for gradual enablement, current default to `false`, and will be set to `true` and then removed once initial development completes.
 * $wgEnablePartialBlocks – This enables the Partial Blocks feature, which gives

Changed configuration
MediaWiki 1.32, now defaults to MIGRATION_NEW instead of MIGRATION_WRITE_BOTH. password is not in the large blacklist. This is enabled by default for the built-in user groups bureaucrat, sysop, interface-admin, and bot. To configure this for other user groups, set the `PasswordNotInLargeBlacklist` flag `true`. password hashing (which requires PHP 7.2 and above). It's designed to resist timing attacks, and (on systems with PHP 7.3+) GPU hacking; if you configure argon2 to be used, by default, it will automatically choose the best available algorithm depending on which version of PHP you have available. To use this, you can set `$wgPasswordDefault = 'argon2';`. update.php will back-populate the new database fields due to the changed setting, which may take some time on large wikis. You can avoid downtime by following a process like that described in T188327.
 * $wgChangeTagsSchemaMigrationStage (T193868) — This temporary setting, added in
 * $wgPasswordPolicy – There is a new password policy to check that the account's
 * $wgPasswordDefault – There is a new password type configuration using Argon2
 * $wgActorTableSchemaMigrationStage now defaults to reading the new schema.

Removed configuration
MediaWiki 1.32, has now been removed. When loading Special:Tags, MediaWiki will now always use the `change_tag_def` instead of the `change_tag` table. $wgDebugTidy – These options, all deprecated since 1.26, have now all been removed, as MediaWiki now always tidies user output. The $wgTidyConfig setting remains only for experimental features and debugging, and should not be used. been removed. If you still desire to disable the parser cache, instead you can set `$wgParserCacheType = CACHE_NONE;`. been removed. Code finding it unset should treat it as being MIGRATION_NEW. the removal of AuthPlugin. to allow sites to configure a file in which to cache the SiteStore database table, but it was never used. SiteStore already caches its information by default using BagOStuff (e.g. Memcached or APC). how much MediaWiki would fudge when trying to minimize the chances of a user.user_touched database update to the "current" timestamp being before the value already there (e.g. due to clock skew between different servers). This is no longer a problem, because the code now ensures the timestamp is always higher than the previous one. The writes are guarded with CAS logic (check and set), which prevents updates that would overlap. been removed.
 * $wgTagStatisticsNewTable (T199334) — This temporary setting, added in
 * $wgUseTidy, $wgTidyBin, $wgTidyConf, $wgTidyOpts, $wgTidyInternal, and
 * $wgEnableParserCache – This setting has been deprecated since 1.26, has now
 * $wgCommentTableSchemaMigrationStage – This temporary migration setting has now
 * $wgAuth – This old setting, deprecated in 1.27, has been removed as part of
 * $wgSitesCacheFile – This configuration was introduced in 1.25 with the intent
 * $wgClockSkewFudge – This setting was used by User.php to let sites adjust by
 * $wgDBmysql5 (T196185) - This experimental setting, deprecated in 1.31, has

New user-facing features in 1.33
to be hidden on Special:UnusedCategories. pages. normalized. language where available. the last time the active users query cache was updated. to modify (example: add tags) log entries.
 * (T96041) __EXPECTUNUSEDCATEGORY__ on a category page causes the category
 * (T210814) SVGs are now by default displayed in wiki language on image
 * Special:CreateAccount now warns the user if their chosen username has to be
 * (T205040) Multilingual images are now be displayed in the current parse
 * Special:ActiveUsers will no longer filter out users who became inactive since
 * (T215675) RecentChange and ManualLogEntry implement new Taggable interface.
 * (T215675) Added a hook, ManualLogEntryBeforePublish, to allow extensions

New developer features in 1.33
additional information about the authentication event. Content::getNativeData for text-based content models. LinksUpdate::getRemovedExternalLinks were introduced. associated with this entry in the patrol log. limited to shell access for now.
 * The AuthManagerLoginAuthenticateAudit hook has a new parameter for
 * TextContent::getText was introduced as a replacement for
 * (T214706) LinksUpdate::getAddedExternalLinks and
 * (T213893) Added 'MaintenanceUpdateAddParams' hook
 * (T219655) The MarkPatrolled hook has a new parameter for the tags
 * (T212472) Extensions can now specify platform abilities they require to work,

New external libraries

 * Added wikimedia/password-blacklist 0.1.4.
 * Added guzzlehttp/guzzle 6.3.3.

Changed external libraries

 * Updated OOUI from v0.29.2 to v0.31.3.
 * Updated OOjs Router from pre-release to v0.2.0.
 * Updated moment from v2.19.3 to v2.24.0.
 * Updated wikimedia/xmp-reader from 0.6.0 to 0.6.2.
 * Updated wikimedia/scoped-callback from 2.0.0 to 3.0.0.
 * Updated jquery-client from 2.0.1 to 2.0.2.
 * Updated pear/net_smtp from 1.8.0 to 1.8.1.
 * Updated cssjanus/cssjanus from 1.2.0 to 1.3.0.
 * Updated wikimedia/php-session-serializer from 1.0.6 to 1.0.7.

Removed external libraries

 * (T219403) jquery.ui.spinner, deprecated since 1.31, was removed.

New developer libraries

 * Added jakub-onderka/php-console-highlighter 0.3.2 explicitly (dev-only).
 * Added mediawiki/mediawiki-phan-config 0.5.0 (dev-only).

Changed developer libraries
* The deprecated IPSet\IPSet alias was removed, Wikimedia\IPSet must be   used instead.
 * Updated wikimedia/ip-set from 1.3.0 to 2.0.1.
 * Updated psy/psysh from 0.9.6 to 0.9.9 (dev-only).
 * Updated nikic/php-parser from 3.1.3 to 3.1.5 (dev-only).
 * Updated mediawiki/mediawiki-codesniffer from 22.0.0 to 25.0.0 (dev-only).
 * Updated qunitjs from 2.6.2 to 2.9.1.

Removed developer libraries
stubs we need, which are kept in the new `.phan/internal_stubs` directory (dev-only).
 * The jetbrains/phpstorm-stubs repository was removed in favour of the minimal

Bug fixes in 1.33
"conflict detected" error when there weren't any conflicts. a non-Latin name on a page with non-Latin characters in title. saveFileDependencies.
 * (T164211) Special:UserRights could sometimes fail with a
 * (T216029) Chrome redirects to Special:BadTitle after editing a section with
 * (T222385) resourceloader: Use AND instead of OR for upsert conds in

Action API changes in 1.33
include the exception class name in a data field named "errorclass". * Class names are not guaranteed to remain stable, and in particular database exceptions will now include the "Wikimedia\Rdbms\" prefix in the class name. * The code including an exception class name is deprecated. In the future, all internal errors will use code "internal_api_error". may return a boolean-true 'scheduled' and no 'logid'. This signifies that the deletion will be processed via the job queue. if entirewatchlist is set, so updates may not be visible immediately the date of user's latest contribution.
 * (T198913) Added 'ApiOptions' hook.
 * The JSON formatversion=2 is no longer experimental.
 * Internal API errors (those with code beginning "internal_api_error") will
 * (T212356) When using action=delete on pages with many revisions, the module
 * action=setnotificationtimestamp will now update the watchlist asynchronously
 * Block info will be added to "blocked" errors from more modules.
 * (T216245) Autoblocks will now be spread by action=edit and action=move.
 * action=query&meta=userinfo has a new uiprop, 'latestcontrib', that returns
 * (T25227) action=logout now requires to be posted and have a csrf token.

Action API internal changes in 1.33
by extensions, are no longer called by MediaWiki, and will emit deprecation notices if your extension attempts to use them: * ApiBase::getDescription (deprecated in 1.25) * ApiBase::getParamDescription (deprecated in 1.25) * ApiBase::getExamples (deprecated in 1.25) * ApiBase::getDescriptionMessage (deprecated in 1.30) Additionally, the 'APIGetDescription' and 'APIGetParamDescription' hooks have been removed, as their only use was to let extensions override values returned by getDescription and getParamDescription, respectively. hyphen. Methods such as ApiBase::dieWithError and ApiMessageTrait::setApiCode will throw an InvalidArgumentException if passed a bad code. parameter. Passing a User object or null is deprecated. deprecated and will be removed in the future.
 * A number of deprecated methods for API documentation, intended for overriding
 * API error codes may only contain ASCII letters, numbers, underscore, and
 * ApiBase::checkTitleUserPermissions now takes an options array as its third
 * The api-feature-usage log channel now has log context. The text message is

Languages updated in 1.33
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.

for NS_TEMPLATE.
 * (T203908) Added language support for Eastern Pwo (kjp).
 * (T213717) Fixed a translation error on Goan Konkani (gom-deva) translations
 * (T212221) Added $digitTransformTable for Santali (sat).
 * (T216479) Added language support for Saisiyat (xsy).
 * (T219728) Added support for new Japanese era name "Reiwa"

Breaking changes in 1.33
Language. Other types are deprecated since 1.32. The parameters $tooltip and $lang are mandatory. Omitting the parameters is deprecated since 1.32. instead. and 'notice-message', which were deprecated in 1.32, were removed. Instead, use 'help', 'help-message', and 'help-messages'. RestbaseVirtualRESTService, deprecated since 1.26, have been removed. Use the RESTBase v1 or Parsoid v3 API instead. parser are being deprecated and ParserOptions::getCanonicalOverrides has always been true at any rate. This was deprecated in 1.32. The pure PHP Remex tidy implementation is now used and no configuration is necessary. by extensions, are no longer called by MediaWiki, and will emit deprecation notices if your extension attempts to use them: * ApiBase::getDescription (deprecated in 1.25) * ApiBase::getParamDescription (deprecated in 1.25) * ApiBase::getExamples (deprecated in 1.25) * ApiBase::getDescriptionMessage (deprecated in 1.30) Additionally, the 'APIGetDescription' and 'APIGetParamDescription' hooks have been removed, as their only use was to let extensions override values returned by getDescription and getParamDescription, respectively. 'LoginUserMigrated', 'UserCreateForm', and 'UserLoginForm', all deprecated by the creation of AuthManager in 1.27, have been removed. This also means that the FakeAuthTemplate and LoginForm classes are removed, that FakeAuthTemplate is no longer passed into LoginSignupSpecialPage->getFieldDefinitions, and that LoginSignupSpecialPage->getBCFieldDefinitions is removed. use 'jquery.i18n'. 1.16, have now been removed. Instead, use $specialPageAliases or $magicWords respectively in a $wgExtensionMessagesFiles file. removed: * getSaveBlacklist * loadPreferenceValues * getOptionFromUser * profilePreferences * skinPreferences * filesPreferences * datetimePreferences * renderingPreferences * editingPreferences * rcPreferences * watchlistPreferences * searchPreferences * miscPreferences * generateSkinOptions * getDateOptions * getImageSizes * getThumbSizes * validateSignature * cleanSignature * getTimezoneOptions * filterIntval * filterTimezoneInput * getTimeZoneList Specifically: mediawiki.api.category, mediawiki.api.edit, mediawiki.api.login, mediawiki.api.options, mediawiki.api.parse, mediawiki.api.upload, mediawiki.api.user, mediawiki.api.watch, mediawiki.api.messages, and mediawiki.api.rollback. deprecated in 1.31, was removed. Title->getCdnUrls. Sanitizer::escapeIdForLink or escapeIdForExternalInterwiki instead. Title->canHaveTalkPage. 1.31, were removed: * Title->isCssOrJsPage — Use Title->isSiteConfigPage * Title->isCssJsSubpage – Use Title->isUserConfigPage * Title->getSkinFromCssJsSubpage – Use Title->getSkinFromConfigSubpage * Title->isCssSubpage – Use Title->isUserCssConfigPage * Title->isJsSubpage – Use Title->isUserJsConfigPage would return the global SiteStore instance, has been removed. You can get to this via MediaWiki\MediaWikiServices::getInstance->getSiteStore directly. Instead, use Language->formatSize with the relevant Language object. version in DummyLinker). You can use TemplatesOnThisPageFormatter directly. use MediaWikiServices::getInstance->getEventRelayerGroup directly.  be unused, and is distinct from OutputPage->addLink, which remains.  JsonContent->getData.  exception ID is the same as the request ID, from WebRequest::getRequestId.  You can use SearchEngine::getNearMatcher instead.  removed. Instead, use WatchedItemStore::updateNotificationTimestamp directly.  been removed. Instead, please use UserGroupMembership::getGroupName and  UserGroupMembership::getGroupMemberName.  wgSessionHandler, both of which were deprecated in 1.27 with the introduction  of SessionManager, has been removed.  MediaWiki\Auth\AuthManager::autoCreateUser instead.  Use require( 'mediawiki.libs.jpegmeta' ) instead.  Use mw.user.getPageviewToken instead.  parameter.  been removed.  has been removed.  should instead use AuthManager. The following no longer exist: * The AuthPlugin class itself and the related AuthPluginUser class and i18n * The AuthPluginSetup and AuthPluginAutoCreate hooks * The transitional wrapper classes AuthPluginPrimaryAuthenticationProvider, AuthManagerAuthPlugin, and AuthManagerAuthPluginUser. * The $wgAuth configuration setting and its use in Setup.php and unit tests LanguageConverter::markNoConversion instead. Use ParserOutput::allCacheVaryingOptions instead. Use CdnCacheUpdate::newFromTitles instead. has been removed. to "Pàgina printzipale". Existing wikis using this content language need to move the main page or change the name through MediaWiki:Mainpage page. Use ::getBlobs instead. removed. Use MediaWikiTestCase::overrideMwServices instead.
 * The parameteter $lang in DifferenceEngine::setTextLanguage must be of type
 * Skin::doEditSectionLink requires type Language for the parameter $lang.
 * Language::truncate, deprecated in 1.31, has been removed.
 * UtfNormal, deprecated in 1.25, was removed. Use UtfNormal\Validator directly
 * (T197179) In OOUI HTMLForm fields, the parameters 'notice', 'notice-messages',
 * (T197179) HTMLFormField::getNotices, deprecated in 1.32, was removed.
 * The "Parsoid v1" compatibility mappings in ParsoidVirtualRESTService and
 * ParserOptions defaults 'tidy' to true now, since the untidy modes of the
 * Support for disabling tidy and external tidy implementations has been removed.
 * A number of deprecated methods for API documentation, intended for overriding
 * The authentication hooks 'AbortAutoAccount' 'AbortNewAccount', 'AbortLogin',
 * The 'jquery.localize' module, deprecated in 1.32, has been removed. Instead,
 * The hooks LanguageGetSpecialPageAliases and LanguageGetMagic, deprecated since
 * The following methods of the Preferences class, deprecated in 1.31, have been
 * mw.util.jsMessage, deprecated in 1.20, was removed. Use mw.notify instead.
 * (T61113) User::EDIT_TOKEN_SUFFIX was removed. It was deprecated since 1.27.
 * The 'mediawiki.api' module aliases, deprecated in 1.32, have been removed.
 * The 'jquery.byteLimit' module alias for 'jquery.lengthLimit',
 * Revision::fetchRevision, deprecated in 1.28, was removed.
 * Class SquidUpdate, deprecated in 1.27, was removed.
 * Title->getSquidURLs, deprecated in 1.27, was removed. Instead, use
 * Title::escapeFragmentForURL, deprecated in 1.30, was removed. Use
 * Title->canTalk, deprecated in 1.30, was removed. Instead, use
 * Title's methods for site and user page related to CSS and JS, deprecated in
 * SiteSQLStore, deprecated in 1.27 and whose only method, ::newInstance,
 * Linker::formatSize, deprecated in 1.28, has been removed (with DummyLinker's).
 * Linker::formatTemplates, deprecated in 1.28, has been removed (along with the
 * EventRelayerGroup::singleton, deprecated in 1.27, has been removed. You can
 * LinkCache->addLink, deprecated in 1.27, has been removed. It is thought to
 * JsonContent->getJsonData, deprecated in 1.25, has been removed. Instead, use
 * MWExceptionHandler::getLogId, deprecated in 1.27, has been removed, as the
 * SearchEngine::getNearMatchResultSet, deprecated in 1.27, has been removed.
 * EmailNotification::updateWatchlistTimestamp, deprecated in 1.27, has been
 * User::getGroupName and ::getGroupMember, both deprecated in 1.29, have
 * Backwards compatibility for setting wgSessionsInObjectCache to false or using
 * SessionManager::autoCreateUser, deprecated in 1.27, has been removed. Use
 * The mw.libs.jpegmeta property, deprecated in 1.31, was removed.
 * The mw.user.stickyRandomId method, deprecated in 1.32, was removed.
 * Removed deprecated class property WikiRevision::$importer.
 * ResourceLoaderFileModule::readStyleFiles now requires its $context
 * The ChangeList::insertArticleLink method, that was deprecated in 1.27, has
 * MessageBlobStore::__construct now requires its $rl parameter.
 * Second parameter to Sanitizer::escapeIdReferenceList (deprecated in 1.31)
 * The 'jquery.xmldom' module has been removed.
 * The 'jquery.mockjax' module has been removed.
 * The 'jquery.hidpi' module, deprecated in 1.32, has been removed.
 * AuthPlugin and related code, deprecated in 1.27, has been removed. Extensions
 * (T217772) The 'wgAvailableSkins' mw.config key in JavaScript, was removed.
 * Language::markNoConversion, deprecated in 1.32, has been removed. Use
 * BagOStuff::modifySimpleRelayEvent method has been removed.
 * ParserOutput::getLegacyOptions, deprecated in 1.30, has been removed.
 * CdnCacheUpdate::newSimplePurge, deprecated in 1.27, has been removed.
 * Handling of multiple arguments by the Block constructor, deprecated in 1.26,
 * The translation of main page in Sardinian (sc) was changed from "Pàgina Base"
 * wfSplitWikiID, deprecated in 1.32, has been removed.
 * MessageBlobStore::getBlob, deprecated in 1.27, has been removed.
 * The .background-size LESS mixin, deprecated in 1.27, has been removed.
 * ReadOnlyMode::clearCache and ConfiguredReadOnlyMode::clearCache have been

Deprecations in 1.33
to be removed in a future release. and is expected to be removed in a future release. introduced in MW 1.17, have been deprecated. These fixes will always be applied for Arabic and Malayalam in the future. Please enable these on your local wiki (if you have them explicitly set to false) and run maintenance/cleanupTitles.php to fix any existing page titles. in 1.27 as part of the AuthManager re-write, now emits deprecation warnings. This will help identify the issue if you added it to $wgAuthManagerConfig. domain ID as a key component and use makeGlobalKey. Title::getDBKey, which doesn't vary case. returns the same information in a more useful format. as the $lang parameter was deprecated. The same applies to DummyLinker. follow best practices, it is reccommended to use 'PasswordNotInLargeBlacklist' instead which blacklists 100,000 commonly used passwords. Title::getUserPermissionsErrors and Title::userCan. Previously, the method was only called in Action::checkCanExecute. Actions should ensure that their requiresUnblock returns the proper result (the default is `true`). Wikimedia\Services. The old name is still supported, but deprecated. specific getters, such as TextContent::getText. needs asynchronous behaviour should use Promises. other means to fetch a properly escaped message string or Message object. testing code for your JavaScript modules, is deprecated. Instead, you can now use the new extension registration key 'QUnitTestModule'. code that needs this behaviour should use OO.ui.debounce/throttle. 'mediawiki.language.specialCharacters' module has been deprecated. Use require( 'mediawiki.language.specialCharacters' ) instead. removed in a future release. ApiBase::checkTitleUserPermissions has been deprecated. Pass an array [ 'user' => $user ] instead. Block::isCreateAccountBlocked and Block::isUsertalkEditAllowed to get and set block properties; use Block::appliesToRight and Block::appliesToUsertalk to check block behaviour. deprecated and will be removed in the future. implementation, use CachingSiteStore instead. SpecialPage::buildPrevNextNavigation instead instead. The setTags method was overriding the tags, addTags doesn't override, only adds new tags. parameter has been deprecated. Please pass the argument number 0. Use ResourceLoader::expandModuleNames instead.
 * The configuration option $wgUseESI has been deprecated, and is expected
 * The configuration option $wgSquidPurgeUseHostHeader has been deprecated,
 * The configuration options $wgFixArabicUnicode and $wgFixMalayalamUnicode,
 * The LegacyHookPreAuthenticationProvider class, deprecated since its creation
 * wfSplitWikiId is now deprecated. Cache key generation should have the wiki
 * (T202094) Title::getUserCaseDBKey is deprecated; instead, please use
 * User::getPasswordValidity is now deprecated. User::checkPasswordValidity
 * For Linker::generateTOC and Linker::tocList, passing strings or booleans
 * The PasswordPolicy 'PasswordCannotBePopular' has been deprecated. To
 * (T208862) Action::requiresUnblock is now called from
 * (T211608) The MediaWiki\Services namespace has been renamed to
 * (T155582) Content::getNativeData has been deprecated. Please use model-
 * The class WebInstallerOutput is now marked as @private.
 * (T209699) The jquery.async module has been deprecated. JavaScript code that
 * Password::equals is deprecated, use verify.
 * BaseTemplate::msgWiki and QuickTemplate::msgWiki will be removed. Use
 * (T126091) The 'ResourceLoaderTestModules' hook, which lets you declare QUnit
 * (T213426) The jquery.throttle-debounce module has been deprecated. JavaScript
 * The mw.language.specialCharacters property from the
 * ChangeTags::purgeTagUsageCache has been deprecated, and is expected to be
 * Passing a User object or null as the third parameter to
 * (T211578) Block::prevents is deprecated. Use Block::isEmailBlocked,
 * The api-feature-usage log channel now has log context. The text message is
 * The FileBasedSiteLookup class has been deprecated. For a cacheable SiteLookup
 * Language::viewPrevNext function is deprecated, use
 * ManualLogEntry::setTags is deprecated, use ManualLogEntry::addTags
 * Block::isValid is deprecated, since it is no longer needed in core.
 * Calling Maintenance::hasArg as well as Maintenance::getArg with no
 * ResourceLoaderContext::expandModuleNames has been deprecated.

Other changes in 1.33
in it. changed to explicitly cast. Subclasses relying on the base-class implementation should check whether they need to override it now. the following hooks will now be triggered upon page deletion in addition to page updates: LinksUpdateConstructed, LinksUpdate, LinksUpdateComplete. LinksUpdateAfterInsert is not triggered since deletions do not cause insertions into links tables. validation, to avoid a mostly unnecessary DB query. html when no link is specified.
 * (T201747) Html::openElement warns if given an element name with a space
 * The implementation of buildStringCast in Wikimedia\Rdbms\Database has
 * BagOStuff::add is now abstract and must explicitly be defined in subclasses.
 * LinksDeletionUpdate is now a subclass of LinksUpdate. As a consequence,
 * Category::newFromID( $id )->getID will now return $id without any
 * On Special:Version, the name for an extension can no longer be arbitrary

Compatibility
MediaWiki 1.33 requires PHP 7.0.13 or later. Although HHVM 3.18.5 or later is supported, it is generally advised to use PHP 7.0.13 or later for long term support.

MySQL/MariaDB is the recommended DBMS. PostgreSQL or SQLite can also be used, but support for them is somewhat less mature. There is experimental support for Oracle and Microsoft SQL Server.

The supported versions are:


 * MySQL 5.5.8 or later
 * PostgreSQL 9.2 or later
 * SQLite 3.8.0 or later
 * Oracle 9.0.1 or later
 * Microsoft SQL Server 2005 (9.00.1399)