RELEASE-NOTES-1.21

Security reminder: MediaWiki does not require PHP's register_globals. If you
have it on, turn it '''off''' if you can.

== MediaWiki 1.21 ==

THIS IS NOT A RELEASE YET

MediaWiki 1.21 is an alpha-quality branch and is not recommended for use in
production.

=== Configuration changes in 1.21 ===
* (bug 29374) $wgVectorUseSimpleSearch is now enabled by default.
* Deprecated $wgAllowRealName is removed. Use $wgHiddenPrefs[] = 'realname'
  instead.
* (bug 39957) Added $wgUnwatchedPageThreshold, specifying minimum count
  of page watchers required for the number to be accessible to users
  without the unwatchedpages permission.
* $wgBug34832TransitionalRollback has been removed.
* (bug 29472) $wgUseDynamicDates has been removed and its functionality
  disabled.

=== New features in 1.21 ===
* (bug 38110) Schema changes (adding or dropping tables, indicies and
  fields) can be now be done separately from from other changes that
  update.php makes.  This is useful in environments that use database
  permissions to restrict schema changes but allow the DB user that
  MediaWiki normally runs as to perform other changes that update.php
  makes.  Schema changes can be run seperately.  See the file UPGRADE
  for more information.
* (bug 34876) jquery.makeCollapsible has been improved in performance.
* Added ContentHandler facility to allow extensions to support other content
  than wikitext. See docs/contenthandler.txt for details.
* New feature was developed for showing high-DPI thumbnails for high-DPI mobile
  and desktop displays (configurable with $wgResponsiveImages).
* Added new backend to represent and store information about sites and site
  specific configuration.
* jQuery upgraded from 1.8.2 to 1.8.3.
* jQuery UI upgraded from 1.8.23 to 1.8.24.
* Added separate fa_sha1 field to filearchive table. This allows sha1
  searches with the api in miser mode for deleted files.
* Add initial and programmatic sorting for tablesorter.
* Add the event "sortEnd.tablesorter", triggered after sorting has completed.
* The Job system was refactored to allow for different backing stores for
  queues as well as cross-wiki access to queues, among other things. The schema
  for the DB queue was changed to support better concurrency and reduce
  deadlock errors.
* Added ApiQueryORM class to facilitate creation of query API modules based on
  tables that have a corresponding ORMTable class.
* (bug 40876) Icon for PSD (Adobe Photoshop) file types.
* (bug 40641) Implemented Special:Version/Credits with a list of contributors.
* (bug 7851) Implemented one-click AJAX patrolling.
* The <data>, <time>, <meta>, and <link> elements are allowed within WikiText
  for use with Microdata.
* The HTML5 <mark> tag has been whitelisted.
* Added ParserCloned hook for when the Parser object is cloned.
* Added AlternateEditPreview hook to allow extensions to replace the page
  preview from the edit page.
* Added EditPage::showStandardInputs:options hook to allow extensions to add
  new fields to the "editOptions" area of the edit form.
* Upload stash DB schema altered to improve upload performance.
* The following global functions are now reporting deprecated warnings in
  debug mode: wfMsg, wfMsgNoTrans, wfMsgForContent, wfMsgForContentNoTrans,
  wfMsgReal, wfMsgGetKey, wfMsgHtml, wfMsgWikiHtml, wfMsgExt, wfEmptyMsg. Use
  the Message class, or the global method wfMessage.
* Added $wgEnableCanonicalServerLink, off by default. If enabled, a
  <link rel=canonical> tag is added to every page indicating the correct server
  to use.
* Debug message emitted by wfDebugLog() will now be prefixed with the group
  name when its logged to the default log file. That is the case whenever the
  group has no key in wgDebugLogGroups, that will help triage the default log.
* (bug 24620) Add types to LogFormatter.
* jQuery JSON upgraded from 2.3 to 2.4.0.
* Added GetDoubleUnderscoreIDs hook, for modifying the list of magic words.
* DatabaseUpdater class has two new methods to ease extensions schema changes:
  dropExtensionIndex and renameExtensionIndex.
* New preference type - 'api'. Preferences of this type are not shown on
  Special:Preferences, but are still available via the action=options API.
* (bug 39397) Hide rollback link if a user is the only contributor of the page.
* $wgPageInfoTransclusionLimit limits the list size of transcluded articles
  on the info action. Default is 50.
* Added action=createaccount to allow user account creation.
* (bug 40124) action=options API also allows for setting of arbitrary
  preferences, provided that their names are prefixed with 'userjs-'. This
  officially reenables the feature that was undocumented and defective
  in MW 1.20 (saving preferences using Special:Preferences cleared any
  additional fields) and which has been disabled in 1.20.1 as a part of
  a security fix (bug 42202).
* Added option to specify "others" as author in extension credits using
  "..." as author name.
* Added the ability to limit the wall clock time used by shell processes,
  as well as the CPU time. Configurable with $wgMaxShellWallClockTime.
* Allow memory of shell subprocesses to be limited using Linux cgroups
  instead of ulimit -v, which tends to cause deadlocks in recent versions
  of ImageMagick. Configurable with $wgShellCgroup.
* Added $wgWhitelistReadRegexp for regex whitelisting.
* (bug 5346) Categories that are redirects will be displayed italic in
  the category links section at the bottom of a page.
* (bug 43915) New maintenance script deleteEqualMessages.php.
* You can now create checkbox option matrixes through the HTMLCheckMatrix
  subclass in HTMLForm.
* WikiText now permits the use of WAI-ARIA's role="presentation" inside of
  html elements and tables. This allows presentational markup, especially
  tables. To be marked up as such.
* maintenance/sql.php learned the --cluster option. Let you run the script
  on some external cluster instead of the primary cluster for a given wiki.
* (bug 20281) test the parsing of inline URLs.
* Added Special:PagesWithProp, which lists pages using a particular page property.
* Implemented language-specific collations for category sorting for 67 languages
  based in latin, greek and cyrillic alphabets. This allows one to *finally* get
  articles to be correctly sorted on category pages. They are named
  'uca-<langcode>', where <langcode> is one of: af, ast, az, be, bg, br, bs, ca,
  co, cs, cy, da, de, dsb, el, en, eo, es, et, eu, fi, fo, fr, fur, fy, ga, gd,
  gl, hr, hsb, hu, is, it, kk, kl, ku, ky, la, lb, lt, lv, mk, mo, mt, nl, no,
  oc, pl, pt, rm, ro, ru, rup, sco, sk, sl, smn, sq, sr, sv, tk, tl, tr, tt, uk,
  uz, vi.

=== Bug fixes in 1.21 ===
* (bug 40353) SpecialDoubleRedirect should support interwiki redirects.
* (bug 40352) fixDoubleRedirects.php should support interwiki redirects.
* (bug 9237) SpecialBrokenRedirect should not list interwiki redirects.
* (bug 34960) Drop unused fields rc_moved_to_ns and rc_moved_to_title from
  recentchanges table.
* (bug 32951) Do not register internal externals with absolute protocol,
  when server has relative protocol.
* (bug 39005) When purging proxies listed in $wgSquidServers using HTTP PURGE
  method requests, we now send a Host header by default, for Varnish
  compatibility. This also works with Squid in reverse-proxy mode. If you wish
  to support Squid configured in forward-proxy mode, set
  $wgSquidPurgeUseHostHeader to false.
* (bug 37020) sql.php with readline eats semicolon.
* (bug 11748) Properly handle optionally-closed HTML tags when Tidy is
  disabled, and don't wrap HTML-syntax definition lists in paragraphs.
* (bug 41409) Diffs while editing an old revision should again diff against the
  current revision.
* (bug 41494) Honor $wgLogExceptionBacktrace when logging non-API exceptions
  caught during API execution.
* (bug 37963) Fixed loading process for user options.
* (bug 26995) Update filename field on Upload page after having sanitized it.
* (bug 41793) Contribution links to users with 0 edits on Special:ListUsers
  didn't show up red.
* (bug 41899) A PHP notice no longer occurs when using the "rvcontinue" API
  parameter.
* (bug 42036) Account creation emails now contain canonical (not
  protocol-relative) URLs.
* (bug 41990) Fix regression: API edit with redirect=true and lacking
  starttimestamp and basetimestamp should not cause an edit conflict.
* (bug 41706) EditPage: Preloaded page should be converted if possible and
  needed.
* (bug 41886) Rowspans are no longer exploded by tablesorter until the table is
  actually sorted.
* (bug 2865)  User interface HTML elements don't use lang attribute.
  (completed the fix by adding the lang attribute to firstHeading).
* (bug 42173) Removed namespace prefixes on Special:UncategorizedCategories.
* (bug 36053) Log in "returnto" feature forgets query parameters if no
  title parameter was specified.
* (bug 42410) API action=edit now returns correct timestamp for the new edit.
* (bug 14901) Email notification mistakes log action for new page creation.
  Enotif no longer sends "page has been created" notifications for some log
  actions. The following events now have a correct message: page creation,
  deletion, move, restore (undeletion), change (edit). Parameter
  $CHANGEDORCREATED is deprecated in 'enotif_body' and scheduled for removal in
  MediaWiki 1.23.
* (bug 457) In the sidebar of Vector, CologneBlue, Monobook, and Monobook-based
  skins, the heading levels have been changed from (variously per skin)
  <h4>, <h5> or <h6> to only <h3>s, with a <h2> hidden heading above them.
  If you are styling or scripting the headings in a custom way, this change
  will require updates to your site's CSS or JS.
* (bug 41342) jquery.suggestions should cancel any active (async) fetches
  before it triggers another fetch.
* (bug 42184) $wgUploadSizeWarning missing second variable.
* (bug 34581) removeUnusedAccounts.php maintenance script now ignores newuser
  log when determining whether an account is used.
* (bug 43379) Gracefully fail if rev_len is unavailable for a revision on the
  History page.
* (bug 42949) API no longer assumes all exceptions are MWException.
* (bug 41733) Hide "New user message" (.usermessage) element from printable view.
* (bug 39062) Special:Contributions will display changes that don't have
  a parent id instead of just an empty bullet item.
* (bug 37209) "LinkCache doesn't currently know about this title" error fixed.
* wfMerge() now works if $wgDiff3 contains spaces
* (bug 43052) mediawiki.action.view.dblClickEdit.dblClickEdit should trigger
  ca-edit click instead opening URL directly.
* (bug 43964) Invalid value of "link" parameter in <gallery> no longer produces
  a fatal error.
* (bug 44775) The username field is not pre-filled when creating an account.
* (bug 45069) wfParseUrl() no longer produces a PHP notice if passed a "mailto:"
  URL without address
* (bug 45012) Creating an account by e-mail can no longer show a
  "password mismatch" error.
* (bug 44599) On Special:Version, HEADs for submodule checkouts (e.g. for
  extensions) performed using Git 1.7.8+ should now appear.

=== API changes in 1.21 ===
* prop=revisions can now report the contentmodel and contentformat.
  See docs/contenthandler.txt.
* action=edit and action=parse now support contentmodel and contentformat
  parameters to control the interpretation of page content.
  See docs/contenthandler.txt for details.
* (bug 35693) ApiQueryImageInfo now suppresses errors when unserializing metadata.
* (bug 40111) Disable minor edit for page/section creation by API.
* (bug 41042) Revert change to action=parse&page=... behavior when the page
  does not exist.
* (bug 27202) Add timestamp sort to list=allimages.
* (bug 43137) Don't return the sha1 of revisions through the API if the content is
  revision-deleted.
* ApiQueryImageInfo now also returns imageinfo for redirects.
* list=alltransclusions added to enumerate every instance of page embedding
* list=alllinks & alltransclusions now allow both 'from' and 'continue' in
  the same query. When both are present, 'from' is simply ignored.
* list=alllinks & alltransclusions now allow 'unique' in generators, to yield
  a list of all link/template target pages instead of source pages.
* BREAKING CHANGE: list=logevents output format changed for details of some log
  types. Specifically, details that were formerly reported under a key like
  "4::foo" will now be reported under a key of simply "foo".
* BREAKING CHANGE: '??_badcontinue' error code was changed to '??badcontinue'
  for all query modules.
* ApiQueryBase adds 'badcontinue' error code if module has 'continue' parameter.
* (bug 35885) Removed version parameter and all getVersion() methods.
* action=options now takes a "resetkinds" option, which allows only resetting
  certain types of preferences when the "reset" option is set.
* (bug 36751) ApiQueryImageInfo now returns imageinfo for the redirect target
  when queried with &redirects=.
* (bug 31849) ApiQueryImageInfo no longer gets confused when asked for info on
  a redirect and its target.
* (bug 43849) ApiQueryImageInfo no longer throws exceptions with ForeignDBRepo
  redirects.
* On error, any warnings generated before that error will be shown in the result.
* action=help suports generalized submodules (modules=query+value), querymodules obsolete
* ApiQueryImageInfo continuation is more reliable. The only major change is
  that the imagerepository property will no longer be set on page objects not
  processed in the current query (i.e. non-images or those skipped due to
  iicontinue).
* Add supports for all pageset capabilities - generators, redirects, converttitles to
  action=purge and action=setnotificationtimestamp.
* (bug 43251) prop=pageprops&ppprop= now accepts multiple props to query.
* ApiQueryImageInfo will now limit the number of calls to File::transform made
  in any one query. If there are too many, iicontinue will be returned.
* action=query&meta=siteinfo&siprop=general will now return the regexes used for
  link trails and link prefices. Added for Parsoid support.
* Added an API query module list=pageswithprop, which lists pages using a
  particular page property.
* Added an API query module list=pagepropnames, which lists all page prop names
  currently in use on the wiki.
* (bug 44921) ApiMain::execute() will now return after the CORS check for an
  HTTP OPTIONS request.
* (bug 44923) action=upload works correctly if the entire file is uploaded in
  the first chunk.
* Added 'continue=' parameter to streamline client iteration over complex query results
* (bug 44909) API parameters may now be marked as type "upload", which is now
  used for action=upload's 'file' and 'chunk' parameters. This type will raise
  an error during parameter validation if the parameter is given but not
  recognized as an uploaded file.
* (bug 44244) prop=info may now return the number of people watching each page.
* (bug 33304) list=allpages will no longer return duplicate entries when
  querying protection.

=== API internal changes in 1.21 ===
* For debugging only, a new global $wgDebugAPI removes many API restrictions when true.
  Never use on the production servers, as this flag introduces security holes.
  Whenever enabled, a warning will also be added to all output.
* ApiModuleManager now handles all submodules (actions,props,lists) and instantiation
* Query stores prop/list/meta as submodules
* ApiPageSet can now be used in any action to process titles/pageids/revids or any generator.
* BREAKING CHANGE: ApiPageSet constructor now has two params instead of three, with only the
  first one keeping its meaning. ApiPageSet is now derived from ApiBase.
* BREAKING CHANGE: ApiQuery::newGenerator() and executeGeneratorModule() were deleted.
* ApiQueryGeneratorBase::setGeneratorMode() now requires a pageset param.
* $wgAPIGeneratorModules is now obsolete and will be ignored.
* Added flags ApiResult::OVERRIDE and ADD_ON_TOP to setElement() and addValue()
* Internal API calls will now include <warnings> in case of unused parameters

=== Languages updated in 1.21 ===

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.

* South Azerbaijani (azb) added.
* (bug 30040) Autonym for nds-nl is now 'Nedersaksies' (was 'Nedersaksisch').
* (bug 34977) Now formatted numbers in Spanish use space as separator
  for thousands, as mandated by the Real Academia Española.
* (bug 35031) Kurdish formatted numbers now use period and comma
  as separators for thousands and decimals respectively.

=== Other changes in 1.21 ===
* BREAKING CHANGE: (bug 44385) Removed the jquery.collapsibleTabs module and
  moved it to the Vector extension. It was entirely Vector-extension-specific,
  deeply interconnected with the extension, and this functionality really
  belongs to the extension instead of the skin anyway. In the unlikely case you
  were using it, you have to either copy it to your extension, or install the
  Vector extension (and possibly disable its features using config settings if
  you don't want them).
* Experimental IBM DB2 support was removed due to lack of interest and maintainership
* BREAKING CHANGE: Filenames of maintenance scripts were standardized into lowerCamelCase
  format, and made more explicit: clear_stats.php -> clearCacheStats.php; 
  clear_interwiki_cache.php -> clearInterwikiCache.php; initStats.php -> initSiteStats.php;
  proxy_check.php -> proxyCheck.php; stats.php -> showCacheStats.php;
  showStats.php -> showSiteStats.php. Class names were renamed accordingly:
  clear_stats -> ClearCacheStats; InitStats -> InitSiteStats; CacheStats -> ShowCacheStats
  ShowStats -> ShowSiteStats.

== Compatibility ==

MediaWiki 1.21 requires PHP 5.3.2 or later.

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.

The supported versions are:

* MySQL 5.0.2 or later
* PostgreSQL 8.3 or later
* SQLite 3.3.7 or later
* Oracle 9.0.1 or later

== Upgrading ==

1.21 has several database changes since 1.20, 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 1.19.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.