MediaWiki 1.20/wmf2

Deployment of MediaWiki 1.20wmf2 to Wikimedia sites
The latest version (labeled "1.20wmf2") of MediaWiki, the software that powers Wikipedia and its sister sites, is currently being deployed to all Wikimedia sites in stages.

We started on April 30th and will continue until May 9th (see the roadmap).

We will continue to deploy the latest software every two weeks. This is intended to minimize disruption and possible issues, and make it easier to identify the cause of problems, since the possibly problematic code will be much more recent.

What's new
This is a very small set of changes, compared to the previous deployments. Developers have also improved the software "under the hood" in many ways. A more detailed list of changes can be found in the draft release notes.
 * Core features:
 * Edit notices can now be translated.
 * Core bugfixes
 * Add a word-separator between help-messages in HTMLForm
 * Space in $separatorTransformTable should be non-breaking in Portuguese, Esperanto and Udmurt.
 * Developer features and fixes:
 * Fixed incorrect hash mismatch errors in the DiffHistoryBlob
 * api.php URL and other entry point URLs are now listed on Special:Version
 * Added GitViewers hook for extensions using external git repositories to have a web-based repository viewer linked to from Special:Version.
 * Add warning and tracking category for preprocessor errors
 * jQuery UI upgraded to 1.8.19.
 * Removed deprecated $wgFilterCallback and the 'filtered' API error.
 * Memcached debug logs can now be sent to their own file logs by setting $wgDebugLogFile['memcached'] to some filepath.
 * Extensions
 * AbuseFilter
 * Diffs on some /details views are stretched horizontally.
 * AntiSpoof
 * - Fixed a character equivalence issue (equivset: 3A5 Υ =&gt; 59 Y)
 * CentralAuth
 * Remove yaseo references
 * CentralNotice
 * Adding documentation and class visibility to class.
 * CheckUser
 * ARIN WHOIS link rot fixed.
 * FlaggedRevs
 * [FlaggedRevs] Section anchor link encoding fixes for.
 * LiquidThreads
 * - Fix for problem with API prop=info with invalid titles
 * Math
 * Update math parser test cases for new rendering defaults
 * MoodBar
 * Fixing.
 * Fixing.
 * This patchset is similar to https://gerrit.wikimedia.org/r/#change,4675
 * Narayam
 * Do not check the string length of regular expression.
 * * Fixing the rule for ~ in Tamil transliteration
 * Fix whitespace.
 * Improvements for Punjabi transliteration.
 * Fix whitespace.
 * Move te transliteration out of beta status. Ref Bug 33480
 * OAI
 * use wfDebug to report unexpected tags in oai page elements
 * use wfDebug to report unexpected tags in oai page elements
 * ProofreadPage
 * The scan does not appear on Opera.
 * Add 'onlysection' parameter to &lt;pages/&gt;.
 * &lt;pagelist/&gt; should show localized page numbers
 * Anonymous users cannot change page status
 * Position of quality buttons should not change
 * &lt;pages&gt; transclusions allow for infinite loop
 * Fix a bug with the pages tag in 1.20-wmf1 relase.
 * Fix an exception thrown when viewing the page.
 * Add 'onlysection' parameter to &lt;pages/&gt;.
 * &lt;pagelist/&gt; should show localized page numbers
 * Anonymous users cannot change page status
 * Position of quality buttons should not change
 * Fix an exception thrown when viewing the page.
 * Replace deprecated $wgUser-&gt;getSkin call.
 * Minor fixes of a JavaScript code.
 * Removing trailing whitespace.
 * Replace deprecated $wgUser-&gt;getSkin call.
 * SimpleSurvey
 * No more pre-r73480 compat hacks!
 * SyntaxHighlight_GeSHi
 * Use CSS classes .mw-code and .mw-code-inline
 * Translate
 * Add desc msg for wiktionary mobile
 * Add .gitignore.
 * Add MessageGroups::getGroupsByType
 * Add option codemaponly to export.php.
 * Avoid infinite loops
 * Better comparing of fuzzy translations
 * Disabled page translation links on mobile site until Translate supports mobile:)
 * Fixed undefined variables
 * Fix PHP notices about undefined indexes
 * Fix typo
 * Get rid of obsolete code
 * Get rid of unused method
 * Make sure there's a directory separator in the path to avoid msgmerge errors.
 * Add option codemaponly to export.php.
 * Avoid TranslateUtils::messageKeyToGroups in MessageHandle
 * Disabled page translation links on mobile site until Translate supports mobile:)
 * MessageCollection::getTags always returns an array.
 * Rename TMessage::setTag to TMessage::addTag per @todo.
 * Special:ManageMessageGroups performance improvements
 * Strict comparison.
 * Use more MessageHandle
 * Use the new method to get temporary directory in tests
 * MessageCollection::getTags always returns an array.
 * Misc cleanups
 * Remove obsolete autoexport.php script.
 * Rename TMessage::setTag to TMessage::addTag per @todo.
 * Special:ManageMessageGroups performance improvements
 * Strict comparison.
 * Use database keys in MessageHandle.
 * Use MessageHandle
 * Use more MessageHandle
 * Use the new method to get temporary directory in tests
 * UploadWizard
 * Weird behavior when clicking on the name or the thumbnail of the file
 * Fix pre-upload preview on IE 10 for Special:UploadWizard
 * Experimental opt-in mode for UploadWizard's chunked uploads feature
 * Fix display order of uploaded files.
 * Fix minor issue in commit a2e63c83634 - JS Error object is called 'Error'.
 * Large Thumbnail Preview popup has scrollbar
 * Fix minor issue in commit a2e63c83634 - JS Error object is called 'Error'.
 * show error if selected file is too large
 * Support chunked uploads in IE 10
 * VisualEditor
 * Accept wikilink parameters with dangling equal ('|arg=|')
 * Add and update an offset map in DocumentNode
 * Add simple warning to indicate that VE is still in early dev.
 * Add tokenizer cache and clone token state on mutation
 * Add .to('text/plain/expanded', cb) support and convert ifeq to use it
 * Add --wikidom flag to parse.js
 * Biggish token transform system refactoring
 * Build out ve.Surface constructor to support multiple editor instances
 * Cleanup terms used in annotation method
 * Clone cached tokens, and fix switch for empty needle
 * Collected tweaks
 * Convert external link syntax stops to stack
 * Created a named method inside a Surface (instead of anonymouse one) to
 * Delay some token duplication until actual mutation happens
 * Disable preformatted text from indents in template args
 * Disallow &lt; and &gt; in external link urls
 * Don't work around html5 library tokenizer attribute reordering
 * Drastically reduce memory usage for template-heavy pages
 * Elminiated isSelection method
 * Fixes for the template fetch retry feature
 * Fixes to template expansion / token transform managers, 296 tests passing.
 * Fix typo
 * Fix up FormatDropdownTool
 * Fix --wikidom and --linearmodel parse.js options; retry on template fetch failures
 * Get rid of selectionDirection. Introduce getDirection methdo in
 * Implement urlencode parser function
 * Improved the appearance of the warning at the top of the editor
 * Improve image option handling
 * Increase number of callbacks per reactor iteration to 4
 * Introduce new method called "proxy" in surfaceView to avoid using the same
 * Make .to more consistent and add optional parentCB arg
 * Match the empty string as whitespace too
 * Add and update an offset map in DocumentNode
 * Add --wikidom flag to parse.js
 * Biggish token transform system refactoring
 * Build out ve.Surface constructor to support multiple editor instances Now setting up multiple toolbars per config Tools & Modes are now configurable per toolbar per instance Base elements are created on demand and no longer id specific Note: There are some bugs with multiple instances.
 * Cleanup terms used in annotation method
 * Fix typo
 * Improved the appearance of the warning at the top of the editor
 * Modify rangeChange event to save selection direction. Renamed Selection method to more suitable name. Misc cleanup Patchset 2, whitespace cleanup Patchset 3: Change values used with selection direction to -1 or 1 1 for left to right (normal) -1 for right to left (opposite) Change-Id: If9ecc721ace1c7550903170f92395947f1ccc22c
 * Put a space in the toolbarDropdownTool-label div for default Addresses dropdown tool ui inconsistency on load
 * Removed line-height from preview panel
 * Removed unused fake cursor div
 * Set inclusion flag for attribute transform managers too
 * Migrate tools from SurfaceObserver Class
 * Modify rangeChange event to save selection direction.
 * Modify VE constructor to have the default set of tool configuration
 * More tweaks: safesubst and image options
 * New Method isSelection in Surface View
 * Nominate more HTML5 sectioning and heading elements for block-level treatment
 * 'Obama finally expands' ;) Misc fixes and documentation updates
 * On annotate, get current selection from model
 * Put a space in the toolbarDropdownTool-label div for default
 * Reduce the need for token cloning slightly
 * Remove dead parser pipeline code
 * Removed unused fake cursor div
 * Rename text/wiki and tokens/wiki to text/x-mediawiki and similar
 * Set inclusion flag for attribute transform managers too
 * Simplify transformToken slightly, and fix JSHint warnings
 * Small tweak in comment about onlyinclude forcing buffered expansion
 * Support noinclude/includeonly/onlyinclude in attributes
 * Token stream transform improvements
 * Track inclusion status on CachedTokenPipeline
 * WebFonts
 * Add supports for fonts with style variants
 * Add supports for fonts with style variants
 * WikiEditor
 * Adding Tamil numerals special character insertion toolbar.
 * Fixes issue where old toolbar was killed, even when the new toolbar was incompatible
 * Don't escape $, not needed in JS
 * Fix syntax error in I1adc6b99fa3e1980d4ce3c565b5f193bcbceb526
 * Adding pretty quotation marks for Hebrew.
 * Adding Tamil numerals special character insertion toolbar.
 * Don't escape $, not needed in JS
 * Moved character 25cc (dotted circle) before the diacritic.
 * RTL fix for special characters insertion links.
 * Set defaultrebase=0 in .gitreview
 * Updating the Gujarati character insertion toolbar.
 * modified as per
 * Revert toolbar preferences saga
 * Set defaultrebase=0 in .gitreview
 * WikiLove
 * better SVG icon
 * WikimediaMaintenance
 * Prioritise Translates RenderJob
 * ZeroRatedMobileAccess
 * Add banner text for carrier
 * Add check for empty return to
 * Add message for Kenya
 * Add Niger and Cameroon banner text for carrier
 * Add support for toggle_view_desktop querystring additions to support warning banner for charges on zero site
 * Fixes for carriers with spaces and only show carrier name with region
 * Fix for clicking on Wikipedia logo to non-whitelisted language provides no warning
 * Switch to using a new hook 'BeforePageDisplayMobile'

If you encounter issues
If, despite our efforts, you encounter issues due to the upgrade; we'll try and fix them as soon as we can. Please report issues [//bugzilla.wikimedia.org/enter_bug.cgi?product=MediaWiki&version=1.20-git in our bug tracker], which is where we look for reports of problems. And the faster you tell us about problems, the faster we can address them.