MediaWiki 1.39

MediaWiki 1.39 is a future long-term support release of MediaWiki. Consult the file for the full list of changes. It was deployed on Wikimedia Foundation wikis through incremental " wmf "-branches between March and September 2022. The 1.39.0 stable release is expected to come out in November 2022. Download or checkout the  branch in Git to follow this release.

New features

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

Action API changes

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

New configuration

 * $wgAutoCreateTempUser – This configures automatic user creation on page save.
 * $wgCopyUploadAllowOnWikiDomainConfig – This configures if administrators can use the MediaWiki:Copyupload-allowed-domains system message to define which domains can be used with the upload-by-url tool.
 * $wgCdnMatchParameterOrder – This can be set to false if MediaWiki is behind a CDN that re-orders query parameters. This will make the code that matches request URLs to canonical CDN URLs insensitive to parameter order.
 * $wgMultiShardSiteStats – This allows you to split site_stats across multiple rows. Only useful for very large, heavily edited wikis. (T306589)

Changed configuration

 * $wgInvalidUsernameCharacters – This setting now contains the char '>', which is now the reserved delimiter for external user names.
 * $wgLocalFileRepo – The default serialization method for file meta-data has been changed to JSON. You can revert it to PHP by setting the property 'useJsonMetadata' to false.
 * $wgLBFactoryConf – The 'configCallback' flag can now be set to a callback function that returns an array with keys to update in $wgLBFactoryConf. This can be used to update the database configuration on the fly, e.g. to take replica hosts out of rotation.
 * $wgDBservers and $wgLBFactoryConf – The DBO_SSL flag in has been deprecated in favour of a boolean "ssl" parameter.
 * $wgObjectCaches – The 'globalKeyLB' and 'localKeyLB' flags are no longer supported.

Removed configuration

 * $wgMultiContentRevisionSchemaMigrationStage - This transition flag, deprecated since MediaWiki 1.35, has been removed; the data migration is over.
 * $wgActorTableSchemaMigrationStage - This transition flag has been removed; the data migration is over.
 * $wgWikiFarmSiteDetector – This experimental setting has been removed without replacement. Use the MW_WIKI_NAME environment variable to specifiy the name of the site for which to load configuration. Using the WIKI_NAME environment variable for this purpose is deprecated.
 * $wgParserCacheUseJson - The ParserCache now always uses JSON serialization. Reading old non-JSON cache entries is still supported. The setting had been deprecated since 1.36.
 * $wgAllowJavaUploads - To allow uploads of JAR files, remove application/java from $wgMimeTypeExclusions.
 * $wgMaxRedirects – This broken feature was removed, as it never worked as intended (T296430).
 * $wgElementTiming – This experimental, default-disabled feature has been removed without replacement.
 * $wgPriorityHints and $wgPriorityHintsRatio – The related experimental feature has been removed without replacement.
 * $wgIncludeLegacyJavaScript – This flag has been removed, without loss of any functionality in this release. Most former "wikibits" functions were removed after deprecation in previous releases. The remaining functions, such as importScript, are now available unconditionally.
 * $wgLegacySchemaConversion - This unused setting has been removed.
 * $wgInterwikiPrefixDisplayTypes - This unused setting has been removed.
 * $wgMangleFlashPolicy – This is no longer functional, and is now deprecated. Users who are somehow still using Flash as a browser extension will be exposed to CSRF vulnerabilities.