RELEASE-NOTES-1.25

Security reminder: If you have PHP's register_globals option set, you must
turn it off. MediaWiki will not work with it enabled.

== MediaWiki 1.25.2 ==

This is a security and maintenance release of the MediaWiki 1.25 branch.

=== Changes since 1.25.1 ===

* (T94116) SECURITY: Compare API watchlist token in constant time
* (T97391) SECURITY: Escape error message strings in thumb.php
* (T106893) SECURITY: Don't leak autoblocked IP addresses on
  Special:DeletedContributions
* (T102562) Fix InstantCommons parameters to handle the new HTTPS-only
  policy of Wikimedia Commons.
* (T100767) Setting a configuration setting for skin or extension to
  false in LocalSettings.php was not working.
* (T100635) API action=opensearch json output no longer breaks when
  $wgDebugToolbar is enabled.
* (T102522) Using an extension.json or skin.json file which has
  a "manifest_version" property for 1.26 compatability will no longer
  trigger warnings.
* (T86156) Running updateSearchIndex.php will not throw an error as
  page_restrictions has been added to the locked table list.
* Special:Version would throw notices if using SVN due to an incorrectly
  named variable. Add an additional check that an index is defined.

== MediaWiki 1.25.1 ==

This is a bug fix release of the MediaWiki 1.25 branch.

=== Changes since 1.25 ===
* (T100351) Fix syntax errors in extension.json of ConfirmEdit extension

== MediaWiki 1.25 ==

MediaWiki 1.25.x is the stable branch and is recommended for use in production.

=== Configuration changes in 1.25 ===
* $wgPageShowWatchingUsers was removed.
* $wgLocalVirtualHosts has been added to replace $wgConf->localVHosts.
* $wgAntiLockFlags was removed.
* $wgJavaScriptTestConfig was removed.
* Edit tokens returned from User::getEditToken may change on every call. Token
  validity must be checked by passing the user-supplied token to
  User::matchEditToken rather than by testing for equality with a
  newly-generated token.
* (T74951) The UserGetLanguageObject hook may be passed any IContextSource
  for its $context parameter. Formerly it was documented as receiving a
  RequestContext specifically.
* Profiling was restructured and $wgProfiler now requires an 'output' parameter.
  See StartProfiler.sample for details.
* $wgMangleFlashPolicy was added to make MediaWiki's mangling of anything that
  might be a flash policy directive configurable.
* ApiOpenSearch now supports XML output. The OpenSearchXml extension should no
  longer be used. If extracts and page images are desired, the TextExtracts and
  PageImages extensions are required.
* $wgOpenSearchTemplate is deprecated in favor of $wgOpenSearchTemplates.
* Edits are now prepared via AJAX as users type edit summaries. This behavior
  can be disabled via $wgAjaxEditStash.
* (T46740) The temporary option $wgIncludejQueryMigrate was removed, along
  with the jQuery Migrate library, as indicated when this option was provided in
  MediaWiki 1.24.
* ProfilerStandard and ProfilerSimpleTrace were removed. Make sure that any
  StartProfiler.php config is updated to reflect this. Xhprof is available
  for zend/hhvm. Also, for hhvm, one can consider using its xenon profiler.
* Default value of $wgSVGConverters['rsvg'] now uses the 'rsvg-convert' binary
  rather than 'rsvg'.
* Default value of $wgSVGConverters['ImageMagick'] now uses transparent
  background with white fallback color, rather than just white background.
 * MediaWikiBagOStuff class removed, make sure any object cache config
   uses SqlBagOStuff instead.
* The 'daemonized' flag must be set to true in $wgJobTypeConf for any redis
  job queues. This means that mediawiki/services/jobrunner service has to
  be installed and running for any such queues to work.
* $wgAutopromoteOnce no longer supports the 'view' event. For keeping some
  compatibility, any 'view' event triggers will still trigger on 'edit'.
* $wgExtensionDirectory was added for when your extensions directory is somewhere
  other than $IP/extensions (as $wgStyleDirectory does with the skins directory).

=== New features in 1.25 ===
* (T64861) Updated plural rules to CLDR 26. Includes incompatible changes
  for plural forms in Russian, Prussian, Tagalog, Manx and several languages
  that fall back to Russian.
* (T60139) ResourceLoaderFileModule now supports language fallback
  for 'languageScripts'.
* Added a new hook, "ContentAlterParserOutput", to allow extensions to modify the
  parser output for a content object before links update.
* (T37785) Enhanced recent changes and extended watchlist are now default.
  Documentation: https://meta.wikimedia.org/wiki/Help:Enhanced_recent_changes
  and https://www.mediawiki.org/wiki/Manual:$wgDefaultUserOptions.
* (T69341) SVG images will no longer be base64-encoded when being embedded
  in CSS. This results in slight size increase before gzip compression (due to
  percent-encoding), but up to 20% decrease after it.
* Update jStorage to v0.4.12.
* MediaWiki now natively supports page status indicators: icons (or short text
  snippets) usually displayed in the top-right corner of the page. They have
  been in use on Wikipedia for a long time, implemented using templates and CSS
  absolute positioning.
  - Basic wikitext syntax: <indicator name="foo">[[File:Foo.svg|20px]]</indicator>
  - Usage instructions: https://www.mediawiki.org/wiki/Help:Page_status_indicators
  - Adjusting custom skins to support indicators:
    https://www.mediawiki.org/wiki/Manual:Skinning#Page_status_indicators
* Edit tokens may now be time-limited: passing a maximum age to
  User::matchEditToken will reject any older tokens.
* The debug logging internals have been overhauled, and are now using the
  PSR-3 interfaces.
* Update CSSJanus to v1.1.1.
* Update lessphp to v0.5.0.
* Added a hook, "ApiOpenSearchSuggest", to allow extensions to provide extracts
  and images for ApiOpenSearch output. The semantics are identical to the
  "OpenSearchXml" hook provided by the OpenSearchXml extension.
* PrefixSearchBackend hook now has an $offset parameter. Combined with $limit,
  this allows for pagination of prefix results. Extensions using this hook
  should implement supporting behavior. Not doing so can result in undefined
  behavior from API clients trying to continue through prefix results.
* Update jQuery from v1.11.1 to v1.11.3.
* External libraries installed via composer will now be displayed
  on Special:Version in their own section. Extensions or skins that are
  installed via composer will not be shown in this section as it is assumed
  they will add the proper credits to the skins or extensions section. They
  can also be accessed through the API via the new siprop=libraries to
  ApiQuerySiteInfo.
* Update QUnit from v1.14.0 to v1.16.0.
* Update Moment.js from v2.8.3 to v2.8.4.
* Special:Tags now allows for manipulating the list of user-modifiable change
  tags.
* Added 'managetags' user right and 'ChangeTagCanCreate', 'ChangeTagCanDelete',
  and 'ChangeTagCanCreate' hooks to allow for managing user-modifiable change
  tags.
* Added 'ChangeTagsListActive' hook, to separate the concepts of "defined" and
  "active" formerly conflated by the 'ListDefinedTags' hook.
* Added TemplateParser class that provides a server-side interface to cachable
  dynamically-compiled Mustache templates (currently uses lightncandy library).
* Clickable anchors for each section heading in the content are now generated
  and appear in the gutter on hovering over the heading.
* Added 'CategoryViewer::doCategoryQuery' and 'CategoryViewer::generateLink' hooks
  to allow extensions to override how links to pages are rendered within NS_CATEGORY
* (T19665) Special:WantedPages only lists page which having at least one red link
  pointing to it.
* New hooks 'ApiMain::moduleManager' and 'ApiQuery::moduleManager', can be
  used for conditional registration of API modules.
* New hook 'EnhancedChangesList::getLogText' to alter, remove or add to the
  links of a group of changes in EnhancedChangesList.
* A full interface for StatsD metric reporting has been added to the context
  interface, reachable via IContextSource::getStats().
* Move the jQuery Client library from being mastered in MediaWiki as v0.1.0 to a
  proper, published library, which is now tagged as v1.0.0.
* A new message (defaulting to blank), 'editnotice-notext', can be shown to users
  when they are editing if no edit notices apply to the page being edited.
* (T94536) You can now make the sitenotice appear to logged-in users only by
  editing MediaWiki:Anonnotice and replacing its content with "". Setting it to
  "-" (default) will continue disable it and fallback to MediaWiki:Sitenotice.
* Modifying the tagging of a revision or log entry is now available via
  Special:EditTags, generally accessed via the revision-deletion-like interface
  on history pages and Special:Log is likely to be more useful.
* Added 'applychangetags' and 'changetags' user rights.
* (T35235) LogFormatter subclasses are now responsible for formatting the
  parameters for API log event output. Extensions should implement the new
  getParametersForApi() method in their log formatters.

==== External libraries ====
* MediaWiki now requires certain external libraries to be installed. In the past
  these were bundled inside the Git repository of MediaWiki core, but now they
  need to be installed separately. For users using the tarball, this will be taken
  care of and no action will be required. Users using Git will either need to use
  composer to fetch dependencies or use the mediawiki/vendor repository which includes
  all dependencies for MediaWiki core and ones used in Wikimedia deployment. Detailed
  instructions can be found at:
  https://www.mediawiki.org/wiki/Download_from_Git#Fetch_external_libraries
* The following libraries are now required:
** psr/log
   This library provides the interfaces set by the PSR-3 standard (http://www.php-fig.org/psr/psr-3/)
   which are used by MediaWiki internally via the
   MediaWiki\Logger\LoggerFactory class.
   See the structured logging RfC (https://www.mediawiki.org/wiki/Requests_for_comment/Structured_logging)
   for more background information.
** cssjanus/cssjanus
   This library was formerly bundled with MediaWiki core and has been removed.
   It automatically flips CSS for RTL support.
** leafo/lessphp
   This library was formerly bundled with MediaWiki core and has been removed.
   It compiles LESS files into CSS.
** wikimedia/cdb
   This library was formerly a part of MediaWiki core, and has been moved into a separate library.
   It provides CDB functions which are used in the Interwiki and Localization caches.
   More information about the library can be found at https://www.mediawiki.org/wiki/CDB.
** liuggio/statsd-php-client
   This library provides a StatsD client API for logging application metrics to a remote server.

=== Bug fixes in 1.25 ===
* (T73003) No additional code will be generated to try to load CSS-embedded
  SVG images in Internet Explorer 6 and 7, as they don't support them anyway.
* (T69021) On Special:BookSources, corrected validation of ISBNs (both
  10- and 13-digit forms) containing "X".
* Page moving was refactored into a MovePage class. As part of that:
** The AbortMove hook was removed.
** MovePageIsValidMove is for extensions to specify whether a page
   cannot be moved for technical reasons, and should not be overridden.
** MovePageCheckPermissions is for checking whether the given user is
   allowed to make the move.
** Title::moveNoAuth() was deprecated. Use the MovePage class instead.
** Title::moveTo() was deprecated. Use the MovePage class instead.
** Title::isValidMoveOperation() broken down into MovePage::isValidMove()
   and MovePage::checkPermissions().
* (T18530) Multiple autocomments are now formatted in an edit summary.
* (T70361) Autocomments containing "/*" are parsed correctly.
* The Special:WhatLinksHere page linked from 'Number of redirects to this page'
  on action=info about a file page does not list file links anymore.
* (T78637) Search bar is not autofocused unless it is empty so that proper scrolling using arrow keys is possible.
* (T50853) Database::makeList() modified to handle 'NULL' separately when building IN clause
* (T85192) Captcha position modified in Usercreate template. As a result:
** extrafields parameter added to Usercreate.php to insert additional data
** 'extend' method added to QuickTemplate to append additional values to any field of data array
* (T86974) Several Title methods now load from the database when necessary
  (instead of returning incorrect results) even when the page ID is known.
* (T74070) Duplicate search for archived files on file upload now omits the extension.
  This requires the fa_sha1 field being populated.
* Removed rel="archives" from the "View history" link, as it did not pass
  HTML validation.
* $wgUseTidy is now set when parserTests are run with the tidy option to match
  output on wiki.
* (T37472) update.php will purge ResourceLoader cache unless --nopurge is passed to it.
* (T72109) mediawiki.language should respect $wgTranslateNumerals in convertNumber().

=== Action API changes in 1.25 ===
* (T67403) XML tag highlighting is now only performed for formats
  "xmlfm" and "wddxfm".
* action=paraminfo supports generalized submodules (modules=query+value),
  querymodules and formatmodules are deprecated
* action=paraminfo no longer outputs descriptions and other help text by
  default. If needed, it may be requested using the new 'helpformat' parameter.
* action=help has been completely rewritten, and outputs help in HTML
  rather than plain text.
* Hitting api.php without specifying an action now displays only the help for
  the main module, with links to submodule help.
* API help is no longer displayed on errors.
* 'uselang' is now a recognized API parameter; "uselang=user" may be used to
  explicitly select the language from the current user's preferences, and
  "uselang=content" may be used to select the wiki's content language.
* Default output format for the API is now jsonfm.
* Simplified continuation will return a "batchcomplete" property in the result
  when a batch of pages is complete.
* Pretty-printed HTML output now has nicer formatting and (if available)
  better syntax highlighting.
* Deprecated list=deletedrevs in favor of newly-added prop=deletedrevisions and
  list=alldeletedrevisions.
* prop=revisions will gracefully continue when given too many revids or titles,
  rather than just ignoring the extras.
* prop=revisions will no longer die if rvcontentformat doesn't match a
  revision's content model; it will instead warn and omit the content.
* If the user has the 'deletedhistory' right, action=query's revids parameter
  will now recognize deleted revids.
* prop=revisions may be used as a generator, generating revids.
* (T68776) format=json results will no longer be corrupted when
  $wgMangleFlashPolicy is in effect. format=php results will cleanly return an
  error instead of returning invalid serialized data.
* Generators may now return data for the generated pages when used with
  action=query.
* Query page data for generator=search and generator=prefixsearch will now
  include an "index" field, which may be used by the client for sorting the
  search results.
* ApiOpenSearch now supports XML output.
* ApiOpenSearch will now output descriptions and URLs as array indexes 2 and 3
  in JSON format.
* (T76051) list=tags will now continue correctly.
* (T76052) list=tags can now indicate whether a tag is defined.
* (T75522) list=prefixsearch now supports continuation
* (T78737) action=expandtemplates can now return page properties.
* (T78690) list=allimages now accepts multiple pipe-separated values
  for the 'aimime' parameter.
* prop=info with inprop=protections will now return applicable protection types
  with the 'restrictiontypes' key.
* (T85417) When resolving redirects, ApiPageSet will now add the targets of
  interwiki redirects to the list of interwiki titles.
* (T85417) When outputting the list of redirect titles, a 'tointerwiki'
  property (like the existing 'tofragment' property) will be set.
* Added action=managetags to allow for managing the list of
  user-modifiable change tags. Actually modifying the tagging of a revision or
  log entry is not implemented yet.
* list=tags has additional properties to indicate 'active' status and tag
  sources.
* siprop=libraries was added to ApiQuerySiteInfo to list installed external libraries.
* (T88010) Added action=checktoken, to test a CSRF token's validity.
* (T88010) Added intestactions to prop=info, to allow querying of
  Title::userCan() via the API.
* Default type param for query list=watchlist and list=recentchanges has
  been changed from all types (e.g. including 'external') to 'edit|new|log'.
* Added formatversion to format=json. Still "experimental" as further changes
  to the output formatting might still be made.
* (T73020) Log event details are now always under a 'params' subkey for
  list=logevents, and a 'logparams' subkey for list=watchlist and
  list=recentchanges.
* Log event details are changing formatting:
  * block events now report flags as an array rather than as a comma-separated
    list.
  * patrol events now report the 'auto' flag as a boolean (absent/empty string
    for BC formats) rather than as an integer.
  * rights events now report the old and new group lists as arrays rather than
    as comma-separated lists.
  * merge events use new-style formatting.
  * delete/event and delete/revision events use new-style formatting.
* The root node and various other nodes will now always be an object in formats
  such as json that distinguish between arrays and objects.
  * Except for action=opensearch where the spec requires an array.

=== Action API internal changes in 1.25 ===
* ApiHelp has been rewritten to support i18n and paginated HTML output.
  Most existing modules should continue working without changes, but should do
  the following:
  * Add an i18n message "apihelp-{$moduleName}-description" to replace getDescription().
  * Add i18n messages "apihelp-{$moduleName}-param-{$param}" for each parameter
    to replace getParamDescription(). If necessary, the settings array returned
    by getParams() can use the new ApiBase::PARAM_HELP_MSG key to override the
    message.
  * Implement getExamplesMessages() to replace getExamples().
* Modules with submodules (like action=query) must have their submodules
  override ApiBase::getParent() to return the correct parent object.
* The 'APIGetDescription' and 'APIGetParamDescription' hooks are deprecated,
  and will have no effect for modules using i18n messages. Use
  'APIGetDescriptionMessages' and 'APIGetParamDescriptionMessages' instead.
* Api formatters will no longer be asked to display the help screen on errors.
* ApiMain::getCredits() was removed. The credits are available in the
  'api-credits' i18n message.
* ApiFormatBase has been changed to support i18n and syntax highlighting via
  extensions with the new 'ApiFormatHighlight' hook. Core syntax highlighting
  has been removed.
* ApiFormatBase now always buffers. Output is done when
  ApiFormatBase::closePrinter is called.
* Much of the logic in ApiQueryRevisions has been split into ApiQueryRevisionsBase.
* The 'revids' parameter supplied by ApiPageSet will now count deleted
  revisions as "good" if the user has the 'deletedhistory' right. New methods
  ApiPageSet::getLiveRevisionIDs() and ApiPageSet::getDeletedRevisionIDs() are
  provided to access just the live or just the deleted revids.
* Added ApiPageSet::setGeneratorData() and ApiPageSet::populateGeneratorData()
  to allow generators to include data in the action=query result.
* New hooks 'ApiMain::moduleManager' and 'ApiQuery::moduleManager', can be
  used for conditional registration of API modules.
* Added ApiBase::lacksSameOriginSecurity() to allow modules to easily check if
  the current request was sent with the 'callback' parameter (or any future
  method that breaks the same-origin policy).
* Profiling methods in ApiBase are deprecated and no longer need to be called.
* ApiResult was greatly overhauled. See inline documentation for details.
* ApiResult will automatically convert objects to strings or arrays (depending
  on whether a __toString() method exists on the object), and will refuse to
  add unsupported value types.
  * An informal interface, ApiSerializable, exists to override the default
    object conversion.
* ApiResult/ApiFormatBase "raw mode" is deprecated.
* ApiFormatXml now assumes defaults and so on instead of throwing errors when
  metadata isn't set.
* (T35235) LogFormatter subclasses are now responsible for formatting log event
  parameters for the API.
* Many modules have changed result data formats. While this shouldn't affect
  clients not using the experimental formatversion=2, code using
  ApiResult::getResultData() without the transformations for backwards
  compatibility may need updating, as will code that wasn't following the old
  conventions for API boolean output.
* The following methods have been deprecated and may be removed in a future
  release:
  * ApiBase::getDescription
  * ApiBase::getParamDescription
  * ApiBase::getExamples
  * ApiBase::makeHelpMsg
  * ApiBase::makeHelpArrayToString
  * ApiBase::makeHelpMsgParameters
  * ApiBase::getModuleProfileName
  * ApiBase::profileIn
  * ApiBase::profileOut
  * ApiBase::safeProfileOut
  * ApiBase::getProfileTime
  * ApiBase::profileDBIn
  * ApiBase::profileDBOut
  * ApiBase::getProfileDBTime
  * ApiBase::getResultData
  * ApiFormatBase::setUnescapeAmps
  * ApiFormatBase::getWantsHelp
  * ApiFormatBase::setHelp
  * ApiFormatBase::formatHTML
  * ApiFormatBase::setBufferResult
  * ApiFormatBase::getDescription
  * ApiFormatBase::getNeedsRawData
  * ApiMain::setHelp
  * ApiMain::reallyMakeHelpMsg
  * ApiMain::makeHelpMsgHeader
  * ApiResult::setRawMode
  * ApiResult::getIsRawMode
  * ApiResult::getData
  * ApiResult::setElement
  * ApiResult::setContent
  * ApiResult::setIndexedTagName_recursive
  * ApiResult::setIndexedTagName_internal
  * ApiResult::setParsedLimit
  * ApiResult::beginContinuation
  * ApiResult::setContinueParam
  * ApiResult::setGeneratorContinueParam
  * ApiResult::endContinuation
  * ApiResult::size
  * ApiResult::convertStatusToArray
  * ApiQueryImageInfo::getPropertyDescriptions
  * ApiQueryLogEvents::addLogParams
* The following classes have been deprecated and may be removed in a future
  release:
  * ApiQueryDeletedrevs

=== Languages updated in 1.25 ===

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 Bugzilla reports.

* Languages added:
** awa (अवधी / Awadhi), thanks to translator 1AnuraagPandey;
** bgn (بلوچی رخشانی / Western Balochi), thanks to translators
   Baloch Afghanistan, Ibrahim khashrowdi and Rachitrali;
** ses (Koyraboro Senni), thanks to translator Songhay.
* (T66440) Kazakh (kk) wikis should no longer forcefully reset the user's
  interface language to kk where unexpected.
* The Chinese conversion table was substantially updated to fix a lot of
  bugs and ensure better reading experience for different variants.

=== Other changes in 1.25 ===
* (T45591) Links to MediaWiki.org translatable help were added to indicators,
  mostly in special pages. Local custom target titles can be placed in the
  relevant '(namespace-X|action name|special page name)-helppage' system
  message. Extensions can use the addHelpLink() function to do the same.
* The skin autodiscovery mechanism, deprecated in MediaWiki 1.23, has been
  removed. See https://www.mediawiki.org/wiki/Manual:Skin_autodiscovery for
  migration guide for creators and users of custom skins that relied on it.
* Javascript variables 'wgFileCanRotate' and 'wgFileExtensions' now only
  available on Special:Upload.
* (T58257) Set site logo from mediawiki.skinning.interface module instead of
  inline styles in the HTML.
* Removed ApiQueryUsers::getAutoGroups(). (deprecated since 1.20)
* Removed XmlDumpWriter::schemaVersion(). (deprecated since 1.20)
* Removed LogEventsList::getDisplayTitle(). (deprecated since 1.20)
* Removed Preferences::trySetUserEmail(). (deprecated since 1.20)
* Removed mw.user.name() and mw.user.anonymous() methods. (deprecated since 1.20)
* Removed 'ok' and 'err' parameters in the mediawiki.api modules. (deprecated
  since 1.20)
* Removed 'async' parameter from the  mw.Api#getCategories() method. (deprecated
  since 1.20)
* Removed 'jquery.json' module. (deprecated since 1.24)
  Use the 'json' module and global JSON object instead.
* Deprecated OutputPage::readOnlyPage() and OutputPage::rateLimited().
  Also, the former will now throw an MWException if called with one or more
  arguments.
* Removed hitcounters and associated code.
* The "temp" zone of the upload respository is now considered private. If it
  already exists (such as under the images/ directory), please make sure that
  the directory is not web readable (e.g. via a .htaccess file).
* BREAKING CHANGE: In the XML dump format used by Special:Export and
  dumpBackup.php, the <model> and <format> tags now apprear before the <text>
  tag, instead of after the <text> and <sha1> tags.
  The new schema version is 0.10, the new schema URI is:
  https://www.mediawiki.org/xml/export-0.10.xsd
* MWFunction::call() and MWFunction::callArray() were removed, having being
  deprecated in 1.22.
* Deprecated the getInternalLinkAttributes, getInternalLinkAttributesObj,
  and getInternalLinkAttributes methods in Linker, and removed
  getExternalLinkAttributes method, which was deprecated in MediaWiki 1.18.
* Removed Sites class, which was deprecated in 1.21 and replaced by SiteSQLStore.
* Added wgRelevantArticleId to the client-side config, for use on special pages.
* Deprecated the TitleIsCssOrJsPage hook. Superseded by the
  ContentHandlerDefaultModelFor hook since MediaWiki 1.21.
* Deprecated the TitleIsWikitextPage hook. Superseded by the
  ContentHandlerDefaultModelFor hook since MediaWiki 1.21.
* Changed parsing of variables in schema (.sql) files:
** The substituted values are no longer parsed. (Formerly, several passes
   were made for each variable, so depending on the order in which variables
   were defined, variables might have been found inside encoded values. This
   is no longer the case.)
** Variables are no longer string encoded when the /*$var*/ syntax is used.
   If string encoding is necessary, use the '{$var}' syntax instead.
** Variable names must only consist of one or more of the characters
   "A-Za-z0-9_".
** In source text of the form '{$A}'{$B}' or `{$A}`{$B}`, where variable A
   does not exist yet variable B does, the latter may not be replaced.
   However, this difference is unlikely to arise in practice.
* (T67278) RFC, PMID, and ISBN "magic links" must be surrounded by non-word
  characters on both sides.
* The FormatAutocomments hook will now receive $pre and $post as booleans,
  rather than as strings that must be prepended or appended to $comment.
* (T30950, T31025) RFC, PMID, and ISBN "magic links" can no longer contain
  newlines; but they can contain &nbsp; and other non-newline whitespace.
* The 'mediawiki.action.edit' ResourceLoader module no longer generates the edit
  toolbar, which has been moved to a separate 'mediawiki.toolbar' module. If you
  relied on this behavior, update your scripts' dependencies.
* HTMLForm's 'vform' display style has been separated to a subclass. Therefore:
  * HTMLForm::isVForm() is now deprecated.
  * You can no longer do this:
      $form = new HTMLForm( … );
      $form->setDisplayFormat( 'vform' ); // throws exception
    Instead, do this:
      $form = HTMLForm::factory( 'vform', … );
* Deprecated Revision methods getRawUser(), getRawUserText() and getRawComment().
* BREAKING CHANGE: mediawiki.user.generateRandomSessionId:
  The alphabet of the prior string returned was A-Za-z0-9 and now it is 0-9A-F
* (T87504) Avoid serving SVG background-images in CSS for Opera 12, which
  renders them incorrectly when combined with border-radius or background-size.
* Removed maintenance script dumpSisterSites.php.
* DatabaseBase class constructors must be called using the array argument style.
  Ideally, DatabaseBase:factory() should be used instead in most cases.
* Deprecated ParserOutput::addSecondaryDataUpdate and ParserOutput::getSecondaryDataUpdates.
  This is a hard deprecation, with getSecondaryDataUpdates returning an empty array and
  addSecondaryDataUpdate throwing an exception. These functions will be removed in 1.26,
  since they interfere with caching of ParserOutput objects.
* Introduced new hook 'SecondaryDataUpdates' that allows extensions to inject custom updates.
* Introduced new hook 'OpportunisticLinksUpdate' that allows extensions to perform
  updates when a page is re-rendered.
* EditPage::attemptSave has been modified not to call handleStatus itself and
  instead just returns the Status object. Extension calling it should be aware of
  this.
* Removed class DBObject. (unused since 1.10)
* wfDiff() is deprecated.
* The -m (maximum replication lag) option of refreshLinks.php was removed.
  It had no effect since MediaWiki 1.18 and should be removed from any cron
  jobs or similar scripts you may have set up.
* (T85864) The following messages no longer support raw html: redirectto,
  thisisdeleted, viewdeleted, editlink, retrievedfrom, version-poweredby-others,
  retrievedfrom, thisisdeleted, viewsourcelink, lastmodifiedat, laggedslavemode,
  protect-summary-cascade
* All BloomCache related code has been removed. This was largely experimental.
* $wgResourceModuleSkinStyles no longer supports per-module local or remote paths. They
  can only be set for the entire skin.
* Removed global function swap(). (deprecated since 1.24)
* Deprecated the ".php5" file extension entry points and the $wgScriptExtension
  configuration variable. Refer to the ".php" files instead. If you want
  ".php5" URLs to continue to work, set up redirects. In Apache, this can be
  done by enabling mod_rewrite and adding the following rules to your
  configuration:

    RewriteEngine On
    RewriteBase /
    RewriteRule ^(.*)\.php5 $1.php [R=301,L]

* The global importScriptURI and importStylesheetURI functions, as well as the
  loadedScripts object, from wikibits.js (deprecated since 1.17) now emit
  warnings through mw.log.warn when accessed.

== Compatibility ==

MediaWiki 1.25 requires PHP 5.3.3 or later. There is experimental support for
HHVM 3.3.0.

MySQL 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 5.0.3 or later
* PostgreSQL 8.3 or later
* SQLite 3.3.7 or later
* Oracle 9.0.1 or later
* Microsoft SQL Server 2005 (9.00.1399)

== Upgrading ==

1.25 has several database changes since 1.24, 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).

If upgrading from before 1.11, and you are using a wiki as a commons
repository, make sure that it is updated as well. Otherwise, errors may arise
due to database schema changes.

If upgrading from before 1.7, you may want to run refreshLinks.php to ensure
new database fields are filled with data.

If you are upgrading from MediaWiki 1.4.x or earlier, you should upgrade to
1.5 first. The upgrade script maintenance/upgrade1_5.php has been removed
with MediaWiki 1.21.

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

See the file UPGRADE for more detailed upgrade instructions.

For notes on 1.24.x and older releases, see HISTORY.

== 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/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.freenode.net.