Merge branch 'mw-1.26'

12 files changed, 394 insertions, 463 deletions

diff --git a/includes/parser/CacheTime.php b/includes/parser/CacheTime.php
index 950c0d46..c4506897 100644
--- a/includes/parser/CacheTime.php
+++ b/includes/parser/CacheTime.php
@@ -47,7 +47,7 @@ class CacheTime {
 	/**
 	 * setCacheTime() sets the timestamp expressing when the page has been rendered.
 	 * This does not control expiry, see updateCacheExpiry() for that!
-	 * @param string $t
+	 * @param string $t TS_MW timestamp
 	 * @return string
 	 */
 	public function setCacheTime( $t ) {
diff --git a/includes/parser/CoreParserFunctions.php b/includes/parser/CoreParserFunctions.php
index 830a68fc..7639e2f8 100644
--- a/includes/parser/CoreParserFunctions.php
+++ b/includes/parser/CoreParserFunctions.php
@@ -41,7 +41,7 @@ class CoreParserFunctions {
 		$noHashFunctions = array(
 			'ns', 'nse', 'urlencode', 'lcfirst', 'ucfirst', 'lc', 'uc',
 			'localurl', 'localurle', 'fullurl', 'fullurle', 'canonicalurl',
-			'canonicalurle', 'formatnum', 'grammar', 'gender', 'plural',
+			'canonicalurle', 'formatnum', 'grammar', 'gender', 'plural', 'bidi',
 			'numberofpages', 'numberofusers', 'numberofactiveusers',
 			'numberofarticles', 'numberoffiles', 'numberofadmins',
 			'numberingroup', 'numberofedits', 'language',
@@ -88,9 +88,13 @@ class CoreParserFunctions {
 		if ( strval( $part1 ) !== '' ) {
 			$args = array_slice( func_get_args(), 2 );
 			$message = wfMessage( $part1, $args )
-				->inLanguage( $parser->getOptions()->getUserLangObj() )->plain();
-
-			return array( $message, 'noparse' => false );
+				->inLanguage( $parser->getOptions()->getUserLangObj() );
+			if ( !$message->exists() ) {
+				// When message does not exists, the message name is surrounded by angle
+				// and can result in a tag, therefore escape the angles
+				return $message->escaped();
+			}
+			return array( $message->plain(), 'noparse' => false );
 		} else {
 			return array( 'found' => false );
 		}
@@ -178,7 +182,9 @@ class CoreParserFunctions {
 			default:
 				$func = 'urlencode';
 		}
-		return $parser->markerSkipCallback( $s, $func );
+		// See T105242, where the choice to kill markers and various
+		// other options were discussed.
+		return $func( $parser->killMarkers( $s ) );
 	}
 
 	public static function lcfirst( $parser, $s = '' ) {
@@ -354,6 +360,15 @@ class CoreParserFunctions {
 	}
 
 	/**
+	 * @param Parser $parser
+	 * @param string $text
+	 * @return string
+	 */
+	public static function bidi( $parser, $text = '' ) {
+		return $parser->getFunctionLang()->embedBidi( $text );
+	}
+
+	/**
 	 * Override the title of the page when viewed, provided we've been given a
 	 * title which will normalise to the canonical title
 	 *
diff --git a/includes/parser/LinkHolderArray.php b/includes/parser/LinkHolderArray.php
index 7026c5ce..b4ca7c8e 100644
--- a/includes/parser/LinkHolderArray.php
+++ b/includes/parser/LinkHolderArray.php
@@ -560,7 +560,6 @@ class LinkHolderArray {
 
 			// for each found variants, figure out link holders and replace
 			foreach ( $varRes as $s ) {
-
 				$variantTitle = Title::makeTitle( $s->page_namespace, $s->page_title );
 				$varPdbk = $variantTitle->getPrefixedDBkey();
 				$vardbk = $variantTitle->getDBkey();
diff --git a/includes/parser/MWTidy.php b/includes/parser/MWTidy.php
index d446ccf6..807842b6 100644
--- a/includes/parser/MWTidy.php
+++ b/includes/parser/MWTidy.php
@@ -22,93 +22,6 @@
  */
 
 /**
- * Class used to hide mw:editsection tokens from Tidy so that it doesn't break them
- * or break on them. This is a bit of a hack for now, but hopefully in the future
- * we may create a real postprocessor or something that will replace this.
- * It's called wrapper because for now it basically takes over MWTidy::tidy's task
- * of wrapping the text in a xhtml block
- *
- * This re-uses some of the parser's UNIQ tricks, though some of it is private so it's
- * duplicated. Perhaps we should create an abstract marker hiding class.
- *
- * @ingroup Parser
- */
-class MWTidyWrapper {
-
-	/**
-	 * @var ReplacementArray
-	 */
-	protected $mTokens;
-
-	protected $mUniqPrefix;
-
-	protected $mMarkerIndex;
-
-	public function __construct() {
-		$this->mTokens = null;
-		$this->mUniqPrefix = null;
-	}
-
-	/**
-	 * @param string $text
-	 * @return string
-	 */
-	public function getWrapped( $text ) {
-		$this->mTokens = new ReplacementArray;
-		$this->mUniqPrefix = "\x7fUNIQ" .
-			dechex( mt_rand( 0, 0x7fffffff ) ) . dechex( mt_rand( 0, 0x7fffffff ) );
-		$this->mMarkerIndex = 0;
-
-		// Replace <mw:editsection> elements with placeholders
-		$wrappedtext = preg_replace_callback( ParserOutput::EDITSECTION_REGEX,
-			array( &$this, 'replaceCallback' ), $text );
-		// ...and <mw:toc> markers
-		$wrappedtext = preg_replace_callback( '/\<\\/?mw:toc\>/',
-			array( &$this, 'replaceCallback' ), $wrappedtext );
-		// ... and <math> tags
-		$wrappedtext = preg_replace_callback( '/\<math(.*?)\<\\/math\>/s',
-			array( &$this, 'replaceCallback' ), $wrappedtext );
-		// Modify inline Microdata <link> and <meta> elements so they say <html-link> and <html-meta> so
-		// we can trick Tidy into not stripping them out by including them in tidy's new-empty-tags config
-		$wrappedtext = preg_replace( '!<(link|meta)([^>]*?)(/{0,1}>)!', '<html-$1$2$3', $wrappedtext );
-
-		// Wrap the whole thing in a doctype and body for Tidy.
-		$wrappedtext = '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"' .
-			' "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html>' .
-			'<head><title>test</title></head><body>' . $wrappedtext . '</body></html>';
-
-		return $wrappedtext;
-	}
-
-	/**
-	 * @param array $m
-	 *
-	 * @return string
-	 */
-	public function replaceCallback( $m ) {
-		$marker = "{$this->mUniqPrefix}-item-{$this->mMarkerIndex}" . Parser::MARKER_SUFFIX;
-		$this->mMarkerIndex++;
-		$this->mTokens->setPair( $marker, $m[0] );
-		return $marker;
-	}
-
-	/**
-	 * @param string $text
-	 * @return string
-	 */
-	public function postprocess( $text ) {
-		// Revert <html-{link,meta}> back to <{link,meta}>
-		$text = preg_replace( '!<html-(link|meta)([^>]*?)(/{0,1}>)!', '<$1$2$3', $text );
-
-		// Restore the contents of placeholder tokens
-		$text = $this->mTokens->replace( $text );
-
-		return $text;
-	}
-
-}
-
-/**
  * Class to interact with HTML tidy
  *
  * Either the external tidy program or the in-process tidy extension
@@ -118,32 +31,24 @@ class MWTidyWrapper {
  * @ingroup Parser
  */
 class MWTidy {
+	private static $instance;
+
 	/**
-	 * Interface with html tidy, used if $wgUseTidy = true.
+	 * Interface with html tidy.
 	 * If tidy isn't able to correct the markup, the original will be
 	 * returned in all its glory with a warning comment appended.
 	 *
-	 * @param string $text Hideous HTML input
+	 * @param string $text HTML input fragment. This should not contain a
+	 *                     <body> or <html> tag.
 	 * @return string Corrected HTML output
 	 */
 	public static function tidy( $text ) {
-		$wrapper = new MWTidyWrapper;
-		$wrappedtext = $wrapper->getWrapped( $text );
-
-		$retVal = null;
-		$correctedtext = self::clean( $wrappedtext, false, $retVal );
-
-		if ( $retVal < 0 ) {
-			wfDebug( "Possible tidy configuration error!\n" );
-			return $text . "\n<!-- Tidy was unable to run -->\n";
-		} elseif ( is_null( $correctedtext ) ) {
-			wfDebug( "Tidy error detected!\n" );
-			return $text . "\n<!-- Tidy found serious XHTML errors -->\n";
+		$driver = self::singleton();
+		if ( !$driver ) {
+			throw new MWException( __METHOD__.
+				': tidy is disabled, caller should have checked MWTidy::isEnabled()' );
 		}
-
-		$correctedtext = $wrapper->postprocess( $correctedtext ); // restore any hidden tokens
-
-		return $correctedtext;
+		return $driver->tidy( $text );
 	}
 
 	/**
@@ -154,170 +59,80 @@ class MWTidy {
 	 * @return bool Whether the HTML is valid
 	 */
 	public static function checkErrors( $text, &$errorStr = null ) {
-		$retval = 0;
-		$errorStr = self::clean( $text, true, $retval );
-		return ( $retval < 0 && $errorStr == '' ) || $retval == 0;
+		$driver = self::singleton();
+		if ( !$driver ) {
+			throw new MWException( __METHOD__.
+				': tidy is disabled, caller should have checked MWTidy::isEnabled()' );
+		}
+		if ( $driver->supportsValidate() ) {
+			return $driver->validate( $text, $errorStr );
+		} else {
+			throw new MWException( __METHOD__ . ": error text return from HHVM tidy is not supported" );
+		}
 	}
 
-	/**
-	 * Perform a clean/repair operation
-	 * @param string $text HTML to check
-	 * @param bool $stderr Whether to read result from STDERR rather than STDOUT
-	 * @param int &$retval Exit code (-1 on internal error)
-	 * @return null|string
-	 * @throws MWException
-	 */
-	private static function clean( $text, $stderr = false, &$retval = null ) {
-		global $wgTidyInternal;
+	public static function isEnabled() {
+		return self::singleton() !== false;
+	}
 
-		if ( $wgTidyInternal ) {
-			if ( wfIsHHVM() ) {
-				if ( $stderr ) {
-					throw new MWException( __METHOD__ . ": error text return from HHVM tidy is not supported" );
+	protected static function singleton() {
+		global $wgUseTidy, $wgTidyInternal, $wgTidyConf, $wgDebugTidy, $wgTidyConfig,
+			$wgTidyBin, $wgTidyOpts;
+
+		if ( self::$instance === null ) {
+			if ( $wgTidyConfig !== null ) {
+				$config = $wgTidyConfig;
+			} elseif ( $wgUseTidy ) {
+				// b/c configuration
+				$config = array(
+					'tidyConfigFile' => $wgTidyConf,
+					'debugComment' => $wgDebugTidy,
+					'tidyBin' => $wgTidyBin,
+					'tidyCommandLine' => $wgTidyOpts );
+				if ( $wgTidyInternal ) {
+					if ( wfIsHHVM() ) {
+						$config['driver'] = 'RaggettInternalHHVM';
+					} else {
+						$config['driver'] = 'RaggettInternalPHP';
+					}
+				} else {
+					$config['driver'] = 'RaggettExternal';
 				}
-				return self::hhvmClean( $text, $retval );
 			} else {
-				return self::phpClean( $text, $stderr, $retval );
+				return false;
 			}
-		} else {
-			return self::externalClean( $text, $stderr, $retval );
-		}
-	}
-
-	/**
-	 * Spawn an external HTML tidy process and get corrected markup back from it.
-	 * Also called in OutputHandler.php for full page validation
-	 *
-	 * @param string $text HTML to check
-	 * @param bool $stderr Whether to read result from STDERR rather than STDOUT
-	 * @param int &$retval Exit code (-1 on internal error)
-	 * @return string|null
-	 */
-	private static function externalClean( $text, $stderr = false, &$retval = null ) {
-		global $wgTidyConf, $wgTidyBin, $wgTidyOpts;
-
-		$cleansource = '';
-		$opts = ' -utf8';
-
-		if ( $stderr ) {
-			$descriptorspec = array(
-				0 => array( 'pipe', 'r' ),
-				1 => array( 'file', wfGetNull(), 'a' ),
-				2 => array( 'pipe', 'w' )
-			);
-		} else {
-			$descriptorspec = array(
-				0 => array( 'pipe', 'r' ),
-				1 => array( 'pipe', 'w' ),
-				2 => array( 'file', wfGetNull(), 'a' )
-			);
-		}
-
-		$readpipe = $stderr ? 2 : 1;
-		$pipes = array();
-
-		$process = proc_open(
-			"$wgTidyBin -config $wgTidyConf $wgTidyOpts$opts", $descriptorspec, $pipes );
-
-		//NOTE: At least on linux, the process will be created even if tidy is not installed.
-		//      This means that missing tidy will be treated as a validation failure.
-
-		if ( is_resource( $process ) ) {
-			// Theoretically, this style of communication could cause a deadlock
-			// here. If the stdout buffer fills up, then writes to stdin could
-			// block. This doesn't appear to happen with tidy, because tidy only
-			// writes to stdout after it's finished reading from stdin. Search
-			// for tidyParseStdin and tidySaveStdout in console/tidy.c
-			fwrite( $pipes[0], $text );
-			fclose( $pipes[0] );
-			while ( !feof( $pipes[$readpipe] ) ) {
-				$cleansource .= fgets( $pipes[$readpipe], 1024 );
+			switch ( $config['driver'] ) {
+				case 'RaggettInternalHHVM':
+					self::$instance = new MediaWiki\Tidy\RaggettInternalHHVM( $config );
+					break;
+				case 'RaggettInternalPHP':
+					self::$instance = new MediaWiki\Tidy\RaggettInternalPHP( $config );
+					break;
+				case 'RaggettExternal':
+					self::$instance = new MediaWiki\Tidy\RaggettExternal( $config );
+					break;
+				case 'Html5Depurate':
+					self::$instance = new MediaWiki\Tidy\Html5Depurate( $config );
+					break;
+				default:
+					throw new MWException( "Invalid tidy driver: \"{$config['driver']}\"" );
 			}
-			fclose( $pipes[$readpipe] );
-			$retval = proc_close( $process );
-		} else {
-			wfWarn( "Unable to start external tidy process" );
-			$retval = -1;
 		}
-
-		if ( !$stderr && $cleansource == '' && $text != '' ) {
-			// Some kind of error happened, so we couldn't get the corrected text.
-			// Just give up; we'll use the source text and append a warning.
-			$cleansource = null;
-		}
-
-		return $cleansource;
+		return self::$instance;
 	}
 
 	/**
-	 * Use the HTML tidy extension to use the tidy library in-process,
-	 * saving the overhead of spawning a new process.
-	 *
-	 * @param string $text HTML to check
-	 * @param bool $stderr Whether to read result from error status instead of output
-	 * @param int &$retval Exit code (-1 on internal error)
-	 * @return string|null
+	 * Set the driver to be used. This is for testing.
+	 * @param TidyDriverBase|false|null $instance
 	 */
-	private static function phpClean( $text, $stderr = false, &$retval = null ) {
-		global $wgTidyConf, $wgDebugTidy;
-
-		if ( ( !wfIsHHVM() && !class_exists( 'tidy' ) ) ||
-			( wfIsHHVM() && !function_exists( 'tidy_repair_string' ) )
-		) {
-			wfWarn( "Unable to load internal tidy class." );
-			$retval = -1;
-
-			return null;
-		}
-
-		$tidy = new tidy;
-		$tidy->parseString( $text, $wgTidyConf, 'utf8' );
-
-		if ( $stderr ) {
-			$retval = $tidy->getStatus();
-			return $tidy->errorBuffer;
-		}
-
-		$tidy->cleanRepair();
-		$retval = $tidy->getStatus();
-		if ( $retval == 2 ) {
-			// 2 is magic number for fatal error
-			// http://www.php.net/manual/en/function.tidy-get-status.php
-			$cleansource = null;
-		} else {
-			$cleansource = tidy_get_output( $tidy );
-			if ( $wgDebugTidy && $retval > 0 ) {
-				$cleansource .= "<!--\nTidy reports:\n" .
-					str_replace( '-->', '--&gt;', $tidy->errorBuffer ) .
-					"\n-->";
-			}
-		}
-
-		return $cleansource;
+	public static function setInstance( $instance ) {
+		self::$instance = $instance;
 	}
 
 	/**
-	 * Use the tidy extension for HHVM from
-	 * https://github.com/wikimedia/mediawiki-php-tidy
-	 *
-	 * This currently does not support the object-oriented interface, but
-	 * tidy_repair_string() can be used for the most common tasks.
-	 *
-	 * @param string $text HTML to check
-	 * @param int &$retval Exit code (-1 on internal error)
-	 * @return string|null
+	 * Destroy the current singleton instance
 	 */
-	private static function hhvmClean( $text, &$retval ) {
-		global $wgTidyConf;
-
-		$cleansource = tidy_repair_string( $text, $wgTidyConf, 'utf8' );
-		if ( $cleansource === false ) {
-			$cleansource = null;
-			$retval = -1;
-		} else {
-			$retval = 0;
-		}
-
-		return $cleansource;
+	public static function destroySingleton() {
+		self::$instance = null;
 	}
 }
diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index ace63a09..c07a08ac 100644
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -87,7 +87,11 @@ class Parser {
 	# \p{Zs} is unicode 'separator, space' category. It covers the space 0x20
 	# as well as U+3000 is IDEOGRAPHIC SPACE for bug 19052
 	const EXT_LINK_URL_CLASS = '[^][<>"\\x00-\\x20\\x7F\p{Zs}]';
-	const EXT_IMAGE_REGEX = '/^(http:\/\/|https:\/\/)([^][<>"\\x00-\\x20\\x7F\p{Zs}]+)
+	# Simplified expression to match an IPv4 or IPv6 address, or
+	# at least one character of a host name (embeds EXT_LINK_URL_CLASS)
+	const EXT_LINK_ADDR = '(?:[0-9.]+|\\[(?i:[0-9a-f:.]+)\\]|[^][<>"\\x00-\\x20\\x7F\p{Zs}])';
+	# RegExp to make image URLs (embeds IPv6 part of EXT_LINK_ADDR)
+	const EXT_IMAGE_REGEX = '/^(http:\/\/|https:\/\/)((?:\\[(?i:[0-9a-f:.]+)\\])?[^][<>"\\x00-\\x20\\x7F\p{Zs}]+)
 		\\/([A-Za-z0-9_.,~%\\-+&;#*?!=()@\\x80-\\xFF]+)\\.((?i)gif|png|jpg|jpeg)$/Sxu';
 
 	# Regular expression for a non-newline space
@@ -114,8 +118,20 @@ class Parser {
 	const OT_MSG = 3;
 	const OT_PLAIN = 4; # like extractSections() - portions of the original are returned unchanged.
 
-	# Marker Suffix needs to be accessible staticly.
+	/**
+	 * @var string Prefix and suffix for temporary replacement strings
+	 * for the multipass parser.
+	 *
+	 * \x7f should never appear in input as it's disallowed in XML.
+	 * Using it at the front also gives us a little extra robustness
+	 * since it shouldn't match when butted up against identifier-like
+	 * string constructs.
+	 *
+	 * Must not consist of all title characters, or else it will change
+	 * the behavior of <nowiki> in a link.
+	 */
 	const MARKER_SUFFIX = "-QINU\x7f";
+	const MARKER_PREFIX = "\x7fUNIQ-";
 
 	# Markers used for wrapping the table of contents
 	const TOC_START = '<mw:toc>';
@@ -206,9 +222,10 @@ class Parser {
 	public $mInputSize = false; # For {{PAGESIZE}} on current page.
 
 	/**
-	 * @var string
-	 */
-	public $mUniqPrefix;
+	 * @var string Deprecated accessor for the strip marker prefix.
+	 * @deprecated since 1.26; use Parser::MARKER_PREFIX instead.
+	 **/
+	public $mUniqPrefix = Parser::MARKER_PREFIX;
 
 	/**
 	 * @var array Array with the language name of each language link (i.e. the
@@ -241,7 +258,8 @@ class Parser {
 		$this->mConf = $conf;
 		$this->mUrlProtocols = wfUrlProtocols();
 		$this->mExtLinkBracketedRegex = '/\[(((?i)' . $this->mUrlProtocols . ')' .
-			self::EXT_LINK_URL_CLASS . '+)\p{Zs}*([^\]\\x00-\\x08\\x0a-\\x1F]*?)\]/Su';
+			self::EXT_LINK_ADDR .
+			self::EXT_LINK_URL_CLASS . '*)\p{Zs}*([^\]\\x00-\\x08\\x0a-\\x1F]*?)\]/Su';
 		if ( isset( $conf['preprocessorClass'] ) ) {
 			$this->mPreprocessorClass = $conf['preprocessorClass'];
 		} elseif ( defined( 'HPHP_VERSION' ) ) {
@@ -336,18 +354,7 @@ class Parser {
 		$this->mLangLinkLanguages = array();
 		$this->currentRevisionCache = null;
 
-		/**
-		 * Prefix for temporary replacement strings for the multipass parser.
-		 * \x07 should never appear in input as it's disallowed in XML.
-		 * Using it at the front also gives us a little extra robustness
-		 * since it shouldn't match when butted up against identifier-like
-		 * string constructs.
-		 *
-		 * Must not consist of all title characters, or else it will change
-		 * the behavior of <nowiki> in a link.
-		 */
-		$this->mUniqPrefix = "\x7fUNIQ" . self::getRandomString();
-		$this->mStripState = new StripState( $this->mUniqPrefix );
+		$this->mStripState = new StripState;
 
 		# Clear these on every parse, bug 4549
 		$this->mTplRedirCache = $this->mTplDomCache = array();
@@ -399,6 +406,9 @@ class Parser {
 		global $wgShowHostnames;
 
 		if ( $clearState ) {
+			// We use U+007F DELETE to construct strip markers, so we have to make
+			// sure that this character does not occur in the input text.
+			$text = strtr( $text, "\x7f", "?" );
 			$magicScopeVariable = $this->lock();
 		}
 
@@ -410,11 +420,6 @@ class Parser {
 			$this->mOutput->resetParseStartTime();
 		}
 
-		# Remove the strip marker tag prefix from the input, if present.
-		if ( $clearState ) {
-			$text = str_replace( $this->mUniqPrefix, '', $text );
-		}
-
 		$oldRevisionId = $this->mRevisionId;
 		$oldRevisionObject = $this->mRevisionObject;
 		$oldRevisionTimestamp = $this->mRevisionTimestamp;
@@ -504,6 +509,9 @@ class Parser {
 			if ( $wgShowHostnames ) {
 				$limitReport .= 'Parsed by ' . wfHostname() . "\n";
 			}
+			$limitReport .= 'Cached time: ' . $this->mOutput->getCacheTime() . "\n";
+			$limitReport .= 'Cache expiry: ' . $this->mOutput->getCacheExpiry() . "\n";
+			$limitReport .= 'Dynamic content: ' . ( $this->mOutput->hasDynamicContent() ? 'true' : 'false' ) . "\n";
 			foreach ( $this->mOutput->getLimitReportData() as $key => $value ) {
 				if ( Hooks::run( 'ParserLimitReportFormat',
 					array( $key, &$value, &$limitReport, false, false )
@@ -686,8 +694,10 @@ class Parser {
 	 * Get a random string
 	 *
 	 * @return string
+	 * @deprecated since 1.26; use wfRandomString() instead.
 	 */
 	public static function getRandomString() {
+		wfDeprecated( __METHOD__, '1.26' );
 		return wfRandomString( 16 );
 	}
 
@@ -705,18 +715,11 @@ class Parser {
 	 * Accessor for mUniqPrefix.
 	 *
 	 * @return string
+	 * @deprecated since 1.26; use Parser::MARKER_PREFIX instead.
 	 */
 	public function uniqPrefix() {
-		if ( !isset( $this->mUniqPrefix ) ) {
-			# @todo FIXME: This is probably *horribly wrong*
-			# LanguageConverter seems to want $wgParser's uniqPrefix, however
-			# if this is called for a parser cache hit, the parser may not
-			# have ever been initialized in the first place.
-			# Not really sure what the heck is supposed to be going on here.
-			return '';
-			# throw new MWException( "Accessing uninitialized mUniqPrefix" );
-		}
-		return $this->mUniqPrefix;
+		wfDeprecated( __METHOD__, '1.26' );
+		return self::MARKER_PREFIX;
 	}
 
 	/**
@@ -907,10 +910,14 @@ class Parser {
 	 * @param array $elements List of element names. Comments are always extracted.
 	 * @param string $text Source text string.
 	 * @param array $matches Out parameter, Array: extracted tags
-	 * @param string $uniq_prefix
+	 * @param string|null $uniq_prefix
 	 * @return string Stripped text
+	 * @since 1.26 The uniq_prefix argument is deprecated.
 	 */
-	public static function extractTagsAndParams( $elements, $text, &$matches, $uniq_prefix = '' ) {
+	public static function extractTagsAndParams( $elements, $text, &$matches, $uniq_prefix = null ) {
+		if ( $uniq_prefix !== null ) {
+			wfDeprecated( __METHOD__ . ' called with $prefix argument', '1.26' );
+		}
 		static $n = 1;
 		$stripped = '';
 		$matches = array();
@@ -938,7 +945,7 @@ class Parser {
 				$inside = $p[4];
 			}
 
-			$marker = "$uniq_prefix-$element-" . sprintf( '%08X', $n++ ) . self::MARKER_SUFFIX;
+			$marker = self::MARKER_PREFIX . "-$element-" . sprintf( '%08X', $n++ ) . self::MARKER_SUFFIX;
 			$stripped .= $marker;
 
 			if ( $close === '/>' ) {
@@ -991,10 +998,10 @@ class Parser {
 	 * @return string
 	 */
 	public function insertStripItem( $text ) {
-		$rnd = "{$this->mUniqPrefix}-item-{$this->mMarkerIndex}-" . self::MARKER_SUFFIX;
+		$marker = self::MARKER_PREFIX . "-item-{$this->mMarkerIndex}-" . self::MARKER_SUFFIX;
 		$this->mMarkerIndex++;
-		$this->mStripState->addGeneral( $rnd, $text );
-		return $rnd;
+		$this->mStripState->addGeneral( $marker, $text );
+		return $marker;
 	}
 
 	/**
@@ -1024,9 +1031,10 @@ class Parser {
 			}
 
 			$first_character = $line[0];
+			$first_two = substr( $line, 0, 2 );
 			$matches = array();
 
-			if ( preg_match( '/^(:*)\{\|(.*)$/', $line, $matches ) ) {
+			if ( preg_match( '/^(:*)\s*\{\|(.*)$/', $line, $matches ) ) {
 				# First check if we are starting a new table
 				$indent_level = strlen( $matches[1] );
 
@@ -1043,7 +1051,7 @@ class Parser {
 				# Don't do any of the following
 				$out .= $outLine . "\n";
 				continue;
-			} elseif ( substr( $line, 0, 2 ) === '|}' ) {
+			} elseif ( $first_two === '|}' ) {
 				# We are ending a table
 				$line = '</table>' . substr( $line, 2 );
 				$last_tag = array_pop( $last_tag_history );
@@ -1061,7 +1069,7 @@ class Parser {
 				}
 				array_pop( $tr_attributes );
 				$outLine = $line . str_repeat( '</dd></dl>', $indent_level );
-			} elseif ( substr( $line, 0, 2 ) === '|-' ) {
+			} elseif ( $first_two === '|-' ) {
 				# Now we have a table row
 				$line = preg_replace( '#^\|-+#', '', $line );
 
@@ -1090,16 +1098,16 @@ class Parser {
 				array_push( $last_tag_history, '' );
 			} elseif ( $first_character === '|'
 				|| $first_character === '!'
-				|| substr( $line, 0, 2 ) === '|+'
+				|| $first_two === '|+'
 			) {
 				# This might be cell elements, td, th or captions
-				if ( substr( $line, 0, 2 ) === '|+' ) {
+				if ( $first_two === '|+' ) {
 					$first_character = '+';
+					$line = substr( $line, 2 );
+				} else {
 					$line = substr( $line, 1 );
 				}
 
-				$line = substr( $line, 1 );
-
 				if ( $first_character === '!' ) {
 					$line = str_replace( '!!', '||', $line );
 				}
@@ -1257,7 +1265,7 @@ class Parser {
 
 		# replaceInternalLinks may sometimes leave behind
 		# absolute URLs, which have to be masked to hide them from replaceExternalLinks
-		$text = str_replace( $this->mUniqPrefix . 'NOPARSE', '', $text );
+		$text = str_replace( self::MARKER_PREFIX . 'NOPARSE', '', $text );
 
 		$text = $this->doMagicLinks( $text );
 		$text = $this->formatHeadings( $text, $origText, $isMain );
@@ -1275,10 +1283,12 @@ class Parser {
 	 * @return string
 	 */
 	private function internalParseHalfParsed( $text, $isMain = true, $linestart = true ) {
-		global $wgUseTidy, $wgAlwaysUseTidy;
-
 		$text = $this->mStripState->unstripGeneral( $text );
 
+		if ( $isMain ) {
+			Hooks::run( 'ParserAfterUnstrip', array( &$this, &$text ) );
+		}
+
 		# Clean up special characters, only run once, next-to-last before doBlockLevels
 		$fixtags = array(
 			# french spaces, last one Guillemet-left
@@ -1323,7 +1333,7 @@ class Parser {
 
 		$text = Sanitizer::normalizeCharReferences( $text );
 
-		if ( ( $wgUseTidy && $this->mOptions->getTidy() ) || $wgAlwaysUseTidy ) {
+		if ( MWTidy::isEnabled() && $this->mOptions->getTidy() ) {
 			$text = MWTidy::tidy( $text );
 		} else {
 			# attempt to sanitize at least some nesting problems
@@ -1374,20 +1384,23 @@ class Parser {
 	public function doMagicLinks( $text ) {
 		$prots = wfUrlProtocolsWithoutProtRel();
 		$urlChar = self::EXT_LINK_URL_CLASS;
+		$addr = self::EXT_LINK_ADDR;
 		$space = self::SPACE_NOT_NL; #  non-newline space
 		$spdash = "(?:-|$space)"; # a dash or a non-newline space
 		$spaces = "$space++"; # possessive match of 1 or more spaces
 		$text = preg_replace_callback(
-			'!(?:                           # Start cases
-				(<a[ \t\r\n>].*?</a>) |     # m[1]: Skip link text
-				(<.*?>) |                   # m[2]: Skip stuff inside HTML elements' . "
-				(\b(?i:$prots)$urlChar+) |  # m[3]: Free external links
-				\b(?:RFC|PMID) $spaces      # m[4]: RFC or PMID, capture number
+			'!(?:                            # Start cases
+				(<a[ \t\r\n>].*?</a>) |      # m[1]: Skip link text
+				(<.*?>) |                    # m[2]: Skip stuff inside
+				                             #       HTML elements' . "
+				(\b(?i:$prots)($addr$urlChar*)) | # m[3]: Free external links
+				                             # m[4]: Post-protocol path
+				\b(?:RFC|PMID) $spaces       # m[5]: RFC or PMID, capture number
 					([0-9]+)\b |
-				\bISBN $spaces (            # m[5]: ISBN, capture number
-					(?: 97[89] $spdash? )?   # optional 13-digit ISBN prefix
-					(?: [0-9]  $spdash? ){9} # 9 digits with opt. delimiters
-					[0-9Xx]                 # check digit
+				\bISBN $spaces (             # m[6]: ISBN, capture number
+					(?: 97[89] $spdash? )?   #  optional 13-digit ISBN prefix
+					(?: [0-9]  $spdash? ){9} #  9 digits with opt. delimiters
+					[0-9Xx]                  #  check digit
 				)\b
 			)!xu", array( &$this, 'magicLinkCallback' ), $text );
 		return $text;
@@ -1407,35 +1420,35 @@ class Parser {
 			return $m[0];
 		} elseif ( isset( $m[3] ) && $m[3] !== '' ) {
 			# Free external link
-			return $this->makeFreeExternalLink( $m[0] );
-		} elseif ( isset( $m[4] ) && $m[4] !== '' ) {
+			return $this->makeFreeExternalLink( $m[0], strlen( $m[4] ) );
+		} elseif ( isset( $m[5] ) && $m[5] !== '' ) {
 			# RFC or PMID
 			if ( substr( $m[0], 0, 3 ) === 'RFC' ) {
 				$keyword = 'RFC';
 				$urlmsg = 'rfcurl';
 				$cssClass = 'mw-magiclink-rfc';
-				$id = $m[4];
+				$id = $m[5];
 			} elseif ( substr( $m[0], 0, 4 ) === 'PMID' ) {
 				$keyword = 'PMID';
 				$urlmsg = 'pubmedurl';
 				$cssClass = 'mw-magiclink-pmid';
-				$id = $m[4];
+				$id = $m[5];
 			} else {
 				throw new MWException( __METHOD__ . ': unrecognised match type "' .
 					substr( $m[0], 0, 20 ) . '"' );
 			}
 			$url = wfMessage( $urlmsg, $id )->inContentLanguage()->text();
 			return Linker::makeExternalLink( $url, "{$keyword} {$id}", true, $cssClass );
-		} elseif ( isset( $m[5] ) && $m[5] !== '' ) {
+		} elseif ( isset( $m[6] ) && $m[6] !== '' ) {
 			# ISBN
-			$isbn = $m[5];
+			$isbn = $m[6];
 			$space = self::SPACE_NOT_NL; #  non-newline space
 			$isbn = preg_replace( "/$space/", ' ', $isbn );
 			$num = strtr( $isbn, array(
 				'-' => '',
 				' ' => '',
 				'x' => 'X',
-			));
+			) );
 			$titleObj = SpecialPage::getTitleFor( 'Booksources', $num );
 			return '<a href="' .
 				htmlspecialchars( $titleObj->getLocalURL() ) .
@@ -1449,11 +1462,12 @@ class Parser {
 	 * Make a free external link, given a user-supplied URL
 	 *
 	 * @param string $url
-	 *
+	 * @param int $numPostProto
+	 *   The number of characters after the protocol.
 	 * @return string HTML
 	 * @private
 	 */
-	public function makeFreeExternalLink( $url ) {
+	public function makeFreeExternalLink( $url, $numPostProto ) {
 
 		$trail = '';
 
@@ -1478,7 +1492,7 @@ class Parser {
 		# Don't break a trailing HTML entity by moving the ; into $trail
 		# This is in hot code, so use substr_compare to avoid having to
 		# create a new string object for the comparison
-		if ( $numSepChars && substr_compare( $url, ";", -$numSepChars, 1 ) === 0) {
+		if ( $numSepChars && substr_compare( $url, ";", -$numSepChars, 1 ) === 0 ) {
 			# more optimization: instead of running preg_match with a $
 			# anchor, which can be slow, do the match on the reversed
 			# string starting at the desired offset.
@@ -1492,6 +1506,12 @@ class Parser {
 			$url = substr( $url, 0, -$numSepChars );
 		}
 
+		# Verify that we still have a real URL after trail removal, and
+		# not just lone protocol
+		if ( strlen( $trail ) >= $numPostProto ) {
+			return $url . $trail;
+		}
+
 		$url = Sanitizer::cleanUrl( $url );
 
 		# Is this an external image?
@@ -1609,12 +1629,10 @@ class Parser {
 							$firstspace = $i;
 						}
 					} elseif ( $x2 === ' ' ) {
-						if ( $firstsingleletterword == -1 ) {
-							$firstsingleletterword = $i;
-							// if $firstsingleletterword is set, we don't
-							// look at the other options, so we can bail early.
-							break;
-						}
+						$firstsingleletterword = $i;
+						// if $firstsingleletterword is set, we don't
+						// look at the other options, so we can bail early.
+						break;
 					} else {
 						if ( $firstmultiletterword == -1 ) {
 							$firstmultiletterword = $i;
@@ -2143,7 +2161,8 @@ class Parser {
 				$link = substr( $link, 1 );
 			}
 
-			$nt = Title::newFromText( $this->mStripState->unstripNoWiki( $link ) );
+			$unstrip = $this->mStripState->unstripNoWiki( $link );
+			$nt = is_string( $unstrip ) ? Title::newFromText( $unstrip ) : null;
 			if ( $nt === null ) {
 				$s .= $prefix . '[[' . $line;
 				continue;
@@ -2351,7 +2370,7 @@ class Parser {
 	 */
 	public function armorLinks( $text ) {
 		return preg_replace( '/\b((?i)' . $this->mUrlProtocols . ')/',
-			"{$this->mUniqPrefix}NOPARSE$1", $text );
+			self::MARKER_PREFIX . "NOPARSE$1", $text );
 	}
 
 	/**
@@ -2623,7 +2642,7 @@ class Parser {
 				$closematch = preg_match(
 					'/(?:<\\/table|<\\/h1|<\\/h2|<\\/h3|<\\/h4|<\\/h5|<\\/h6|'
 						. '<td|<th|<\\/?blockquote|<\\/?div|<hr|<\\/pre|<\\/p|<\\/mw:|'
-						. $this->mUniqPrefix
+						. self::MARKER_PREFIX
 						. '-pre|<\\/li|<\\/ul|<\\/ol|<\\/dl|<\\/?center)/iS',
 					$t
 				);
@@ -3305,7 +3324,8 @@ class Parser {
 	 */
 	public function replaceVariables( $text, $frame = false, $argsOnly = false ) {
 		# Is there any text? Also, Prevent too big inclusions!
-		if ( strlen( $text ) < 1 || strlen( $text ) > $this->mOptions->getMaxIncludeSize() ) {
+		$textSize = strlen( $text );
+		if ( $textSize < 1 || $textSize > $this->mOptions->getMaxIncludeSize() ) {
 			return $text;
 		}
 
@@ -3435,7 +3455,6 @@ class Parser {
 
 		# SUBST
 		if ( !$found ) {
-
 			$substMatch = $this->mSubstWords->matchStartAndRemove( $part1 );
 
 			# Possibilities for substMatch: "subst", "safesubst" or FALSE
@@ -3493,7 +3512,6 @@ class Parser {
 
 		# Parser functions
 		if ( !$found ) {
-
 			$colonPos = strpos( $part1, ':' );
 			if ( $colonPos !== false ) {
 				$func = substr( $part1, 0, $colonPos );
@@ -3892,7 +3910,11 @@ class Parser {
 		// Defaults to Parser::statelessFetchTemplate()
 		$templateCb = $this->mOptions->getTemplateCallback();
 		$stuff = call_user_func( $templateCb, $title, $this );
+		// We use U+007F DELETE to distinguish strip markers from regular text.
 		$text = $stuff['text'];
+		if ( is_string( $stuff['text'] ) ) {
+			$text = strtr( $text, "\x7f", "?" );
+		}
 		$finalTitle = isset( $stuff['finalTitle'] ) ? $stuff['finalTitle'] : $title;
 		if ( isset( $stuff['deps'] ) ) {
 			foreach ( $stuff['deps'] as $dep ) {
@@ -4186,7 +4208,7 @@ class Parser {
 		$name = $frame->expand( $params['name'] );
 		$attrText = !isset( $params['attr'] ) ? null : $frame->expand( $params['attr'] );
 		$content = !isset( $params['inner'] ) ? null : $frame->expand( $params['inner'] );
-		$marker = "{$this->mUniqPrefix}-$name-"
+		$marker = self::MARKER_PREFIX . "-$name-"
 			. sprintf( '%08X', $this->mMarkerIndex++ ) . self::MARKER_SUFFIX;
 
 		$isFunctionTag = isset( $this->mFunctionTagHooks[strtolower( $name )] ) &&
@@ -4431,7 +4453,7 @@ class Parser {
 		$prevlevel = 0;
 		$toclevel = 0;
 		$prevtoclevel = 0;
-		$markerRegex = "{$this->mUniqPrefix}-h-(\d+)-" . self::MARKER_SUFFIX;
+		$markerRegex = self::MARKER_PREFIX . "-h-(\d+)-" . self::MARKER_SUFFIX;
 		$baseTitleText = $this->mTitle->getPrefixedDBkey();
 		$oldType = $this->mOutputType;
 		$this->setOutputType( self::OT_WIKI );
@@ -4442,7 +4464,9 @@ class Parser {
 		$tocraw = array();
 		$refers = array();
 
-		foreach ( $matches[3] as $headline ) {
+		$headlines = $numMatches !== false ? $matches[3] : array();
+
+		foreach ( $headlines as $headline ) {
 			$isTemplate = false;
 			$titleText = false;
 			$sectionIndex = false;
@@ -4547,6 +4571,12 @@ class Parser {
 				array( '', '<$1>' ),
 				$safeHeadline
 			);
+
+			# Strip '<span></span>', which is the result from the above if
+			# <span id="foo"></span> is used to produce an additional anchor
+			# for a section.
+			$tocline = str_replace( '<span></span>', '', $tocline );
+
 			$tocline = trim( $tocline );
 
 			# For the anchor, strip out HTML-y stuff period
@@ -5068,7 +5098,7 @@ class Parser {
 	 * in the Parser class.
 	 *
 	 * This interface (introduced r61913) appears to be undocumented, but
-	 * 'markerName' is used by some core tag hooks to override which strip
+	 * 'markerType' is used by some core tag hooks to override which strip
 	 * array their results are placed in. **Use great caution if attempting
 	 * this interface, as it is not documented and injudicious use could smash
 	 * private variables.**
@@ -5391,9 +5421,10 @@ class Parser {
 						case 'gallery-internal-link':
 							$linkValue = strip_tags( $this->replaceLinkHoldersText( $match ) );
 							$chars = self::EXT_LINK_URL_CLASS;
+							$addr = self::EXT_LINK_ADDR;
 							$prots = $this->mUrlProtocols;
 							//check to see if link matches an absolute url, if not then it must be a wiki link.
-							if ( preg_match( "/^($prots)$chars+$/u", $linkValue ) ) {
+							if ( preg_match( "/^($prots)$addr$chars*$/u", $linkValue ) ) {
 								$link = $linkValue;
 							} else {
 								$localLinkTitle = Title::newFromText( $linkValue );
@@ -5575,13 +5606,14 @@ class Parser {
 							break;
 						case 'link':
 							$chars = self::EXT_LINK_URL_CLASS;
+							$addr = self::EXT_LINK_ADDR;
 							$prots = $this->mUrlProtocols;
 							if ( $value === '' ) {
 								$paramName = 'no-link';
 								$value = true;
 								$validated = true;
 							} elseif ( preg_match( "/^((?i)$prots)/", $value ) ) {
-								if ( preg_match( "/^((?i)$prots)$chars+$/u", $value, $m ) ) {
+								if ( preg_match( "/^((?i)$prots)$addr$chars*$/u", $value, $m ) ) {
 									$paramName = 'link-url';
 									$this->mOutput->addExternalLink( $value );
 									if ( $this->mOptions->getExternalLinkTarget() ) {
@@ -5770,7 +5802,7 @@ class Parser {
 	public function replaceTransparentTags( $text ) {
 		$matches = array();
 		$elements = array_keys( $this->mTransparentTagHooks );
-		$text = self::extractTagsAndParams( $elements, $text, $matches, $this->mUniqPrefix );
+		$text = self::extractTagsAndParams( $elements, $text, $matches );
 		$replacements = array();
 
 		foreach ( $matches as $marker => $data ) {
@@ -6229,7 +6261,7 @@ class Parser {
 		$i = 0;
 		$out = '';
 		while ( $i < strlen( $s ) ) {
-			$markerStart = strpos( $s, $this->mUniqPrefix, $i );
+			$markerStart = strpos( $s, self::MARKER_PREFIX, $i );
 			if ( $markerStart === false ) {
 				$out .= call_user_func( $callback, substr( $s, $i ) );
 				break;
@@ -6420,4 +6452,15 @@ class Parser {
 			return $this;
 		}
 	}
+
+	/**
+	 * Set's up the PHP implementation of OOUI for use in this request
+	 * and instructs OutputPage to enable OOUI for itself.
+	 *
+	 * @since 1.26
+	 */
+	public function enableOOUI() {
+		OutputPage::setupOOUI();
+		$this->mOutput->setEnableOOUI( true );
+	}
 }
diff --git a/includes/parser/ParserCache.php b/includes/parser/ParserCache.php
index bc8e4a69..abff5435 100644
--- a/includes/parser/ParserCache.php
+++ b/includes/parser/ParserCache.php
@@ -26,7 +26,7 @@
  * @todo document
  */
 class ParserCache {
-	/** @var MWMemcached */
+	/** @var BagOStuff */
 	private $mMemc;
 	/**
 	 * Get an instance of this object
@@ -44,20 +44,19 @@ class ParserCache {
 
 	/**
 	 * Setup a cache pathway with a given back-end storage mechanism.
-	 * May be a memcached client or a BagOStuff derivative.
 	 *
-	 * @param MWMemcached $memCached
+	 * This class use an invalidation strategy that is compatible with
+	 * MultiWriteBagOStuff in async replication mode.
+	 *
+	 * @param BagOStuff $memCached
 	 * @throws MWException
 	 */
-	protected function __construct( $memCached ) {
-		if ( !$memCached ) {
-			throw new MWException( "Tried to create a ParserCache with an invalid memcached" );
-		}
+	protected function __construct( BagOStuff $memCached ) {
 		$this->mMemc = $memCached;
 	}
 
 	/**
-	 * @param Article $article
+	 * @param WikiPage $article
 	 * @param string $hash
 	 * @return mixed|string
 	 */
@@ -73,7 +72,7 @@ class ParserCache {
 	}
 
 	/**
-	 * @param Article $article
+	 * @param WikiPage $article
 	 * @return mixed|string
 	 */
 	protected function getOptionsKey( $article ) {
@@ -91,7 +90,7 @@ class ParserCache {
 	 * English preferences. That's why we take into account *all* user
 	 * options. (r70809 CR)
 	 *
-	 * @param Article $article
+	 * @param WikiPage $article
 	 * @param ParserOptions $popts
 	 * @return string
 	 */
@@ -103,7 +102,7 @@ class ParserCache {
 
 	/**
 	 * Retrieve the ParserOutput from ParserCache, even if it's outdated.
-	 * @param Article $article
+	 * @param WikiPage $article
 	 * @param ParserOptions $popts
 	 * @return ParserOutput|bool False on failure
 	 */
@@ -126,7 +125,7 @@ class ParserCache {
 	 *
 	 * @todo Document parameter $useOutdated
 	 *
-	 * @param Article $article
+	 * @param WikiPage $article
 	 * @param ParserOptions $popts
 	 * @param bool $useOutdated (default true)
 	 * @return bool|mixed|string
@@ -141,15 +140,15 @@ class ParserCache {
 
 		// Determine the options which affect this article
 		$optionsKey = $this->mMemc->get( $this->getOptionsKey( $article ) );
-		if ( $optionsKey != false ) {
+		if ( $optionsKey instanceof CacheTime ) {
 			if ( !$useOutdated && $optionsKey->expired( $article->getTouched() ) ) {
-				wfIncrStats( "pcache_miss_expired" );
+				wfIncrStats( "pcache.miss.expired" );
 				$cacheTime = $optionsKey->getCacheTime();
 				wfDebug( "Parser options key expired, touched " . $article->getTouched()
 					. ", epoch $wgCacheEpoch, cached $cacheTime\n" );
 				return false;
 			} elseif ( $optionsKey->isDifferentRevision( $article->getLatest() ) ) {
-				wfIncrStats( "pcache_miss_revid" );
+				wfIncrStats( "pcache.miss.revid" );
 				$revId = $article->getLatest();
 				$cachedRevId = $optionsKey->getCacheRevisionId();
 				wfDebug( "ParserOutput key is for an old revision, latest $revId, cached $cachedRevId\n" );
@@ -176,7 +175,7 @@ class ParserCache {
 	 * Retrieve the ParserOutput from ParserCache.
 	 * false if not found or outdated.
 	 *
-	 * @param Article $article
+	 * @param WikiPage|Article $article
 	 * @param ParserOptions $popts
 	 * @param bool $useOutdated (default false)
 	 *
@@ -195,14 +194,14 @@ class ParserCache {
 
 		$parserOutputKey = $this->getKey( $article, $popts, $useOutdated );
 		if ( $parserOutputKey === false ) {
-			wfIncrStats( 'pcache_miss_absent' );
+			wfIncrStats( 'pcache.miss.absent' );
 			return false;
 		}
 
 		$value = $this->mMemc->get( $parserOutputKey );
 		if ( !$value ) {
 			wfDebug( "ParserOutput cache miss.\n" );
-			wfIncrStats( "pcache_miss_absent" );
+			wfIncrStats( "pcache.miss.absent" );
 			return false;
 		}
 
@@ -213,20 +212,28 @@ class ParserCache {
 		// key. Force it here. See bug 31445.
 		$value->setEditSectionTokens( $popts->getEditSection() );
 
+		$wikiPage = method_exists( $article, 'getPage' )
+			? $article->getPage()
+			: $article;
+
 		if ( !$useOutdated && $value->expired( $touched ) ) {
-			wfIncrStats( "pcache_miss_expired" );
+			wfIncrStats( "pcache.miss.expired" );
 			$cacheTime = $value->getCacheTime();
 			wfDebug( "ParserOutput key expired, touched $touched, "
 				. "epoch $wgCacheEpoch, cached $cacheTime\n" );
 			$value = false;
 		} elseif ( $value->isDifferentRevision( $article->getLatest() ) ) {
-			wfIncrStats( "pcache_miss_revid" );
+			wfIncrStats( "pcache.miss.revid" );
 			$revId = $article->getLatest();
 			$cachedRevId = $value->getCacheRevisionId();
 			wfDebug( "ParserOutput key is for an old revision, latest $revId, cached $cachedRevId\n" );
 			$value = false;
+		} elseif ( Hooks::run( 'RejectParserCacheValue', array( $value, $wikiPage, $popts ) ) === false ) {
+			wfIncrStats( 'pcache.miss.rejected' );
+			wfDebug( "ParserOutput key valid, but rejected by RejectParserCacheValue hook handler.\n" );
+			$value = false;
 		} else {
-			wfIncrStats( "pcache_hit" );
+			wfIncrStats( "pcache.hit" );
 		}
 
 		return $value;
@@ -276,6 +283,8 @@ class ParserCache {
 
 			// ...and its pointer
 			$this->mMemc->set( $this->getOptionsKey( $page ), $optionsKey, $expire );
+
+			Hooks::run( 'ParserCacheSaveComplete', array( $this, $parserOutput, $page->getTitle(), $popts, $revId ) );
 		} else {
 			wfDebug( "Parser output was marked as uncacheable and has not been saved.\n" );
 		}
diff --git a/includes/parser/ParserDiffTest.php b/includes/parser/ParserDiffTest.php
index 174c1d61..32f5d068 100644
--- a/includes/parser/ParserDiffTest.php
+++ b/includes/parser/ParserDiffTest.php
@@ -29,7 +29,6 @@ class ParserDiffTest
 	public $parsers;
 	public $conf;
 	public $shortOutput = false;
-	public $dtUniqPrefix;
 
 	public function __construct( $conf ) {
 		if ( !isset( $conf['parsers'] ) ) {
@@ -43,12 +42,6 @@ class ParserDiffTest
 			return;
 		}
 
-		global $wgHooks;
-		static $doneHook = false;
-		if ( !$doneHook ) {
-			$doneHook = true;
-			$wgHooks['ParserClearState'][] = array( $this, 'onClearState' );
-		}
 		if ( isset( $this->conf['shortOutput'] ) ) {
 			$this->shortOutput = $this->conf['shortOutput'];
 		}
@@ -126,18 +119,4 @@ class ParserDiffTest
 			$parser->setFunctionHook( $id, $callback, $flags );
 		}
 	}
-
-	/**
-	 * @param Parser $parser
-	 * @return bool
-	 */
-	public function onClearState( &$parser ) {
-		// hack marker prefixes to get identical output
-		if ( !isset( $this->dtUniqPrefix ) ) {
-			$this->dtUniqPrefix = $parser->uniqPrefix();
-		} else {
-			$parser->mUniqPrefix = $this->dtUniqPrefix;
-		}
-		return true;
-	}
 }
diff --git a/includes/parser/ParserOptions.php b/includes/parser/ParserOptions.php
index 100656d1..1073aed8 100644
--- a/includes/parser/ParserOptions.php
+++ b/includes/parser/ParserOptions.php
@@ -34,145 +34,145 @@ class ParserOptions {
 	/**
 	 * Interlanguage links are removed and returned in an array
 	 */
-	public $mInterwikiMagic;
+	private $mInterwikiMagic;
 
 	/**
 	 * Allow external images inline?
 	 */
-	public $mAllowExternalImages;
+	private $mAllowExternalImages;
 
 	/**
 	 * If not, any exception?
 	 */
-	public $mAllowExternalImagesFrom;
+	private $mAllowExternalImagesFrom;
 
 	/**
 	 * If not or it doesn't match, should we check an on-wiki whitelist?
 	 */
-	public $mEnableImageWhitelist;
+	private $mEnableImageWhitelist;
 
 	/**
 	 * Date format index
 	 */
-	public $mDateFormat = null;
+	private $mDateFormat = null;
 
 	/**
 	 * Create "edit section" links?
 	 */
-	public $mEditSection = true;
+	private $mEditSection = true;
 
 	/**
 	 * Allow inclusion of special pages?
 	 */
-	public $mAllowSpecialInclusion;
+	private $mAllowSpecialInclusion;
 
 	/**
 	 * Use tidy to cleanup output HTML?
 	 */
-	public $mTidy = false;
+	private $mTidy = false;
 
 	/**
 	 * Which lang to call for PLURAL and GRAMMAR
 	 */
-	public $mInterfaceMessage = false;
+	private $mInterfaceMessage = false;
 
 	/**
 	 * Overrides $mInterfaceMessage with arbitrary language
 	 */
-	public $mTargetLanguage = null;
+	private $mTargetLanguage = null;
 
 	/**
 	 * Maximum size of template expansions, in bytes
 	 */
-	public $mMaxIncludeSize;
+	private $mMaxIncludeSize;
 
 	/**
 	 * Maximum number of nodes touched by PPFrame::expand()
 	 */
-	public $mMaxPPNodeCount;
+	private $mMaxPPNodeCount;
 
 	/**
 	 * Maximum number of nodes generated by Preprocessor::preprocessToObj()
 	 */
-	public $mMaxGeneratedPPNodeCount;
+	private $mMaxGeneratedPPNodeCount;
 
 	/**
 	 * Maximum recursion depth in PPFrame::expand()
 	 */
-	public $mMaxPPExpandDepth;
+	private $mMaxPPExpandDepth;
 
 	/**
 	 * Maximum recursion depth for templates within templates
 	 */
-	public $mMaxTemplateDepth;
+	private $mMaxTemplateDepth;
 
 	/**
 	 * Maximum number of calls per parse to expensive parser functions
 	 */
-	public $mExpensiveParserFunctionLimit;
+	private $mExpensiveParserFunctionLimit;
 
 	/**
 	 * Remove HTML comments. ONLY APPLIES TO PREPROCESS OPERATIONS
 	 */
-	public $mRemoveComments = true;
+	private $mRemoveComments = true;
 
 	/**
 	 * Callback for current revision fetching. Used as first argument to call_user_func().
 	 */
-	public $mCurrentRevisionCallback =
+	private $mCurrentRevisionCallback =
 		array( 'Parser', 'statelessFetchRevision' );
 
 	/**
 	 * Callback for template fetching. Used as first argument to call_user_func().
 	 */
-	public $mTemplateCallback =
+	private $mTemplateCallback =
 		array( 'Parser', 'statelessFetchTemplate' );
 
 	/**
 	 * Enable limit report in an HTML comment on output
 	 */
-	public $mEnableLimitReport = false;
+	private $mEnableLimitReport = false;
 
 	/**
 	 * Timestamp used for {{CURRENTDAY}} etc.
 	 */
-	public $mTimestamp;
+	private $mTimestamp;
 
 	/**
 	 * Target attribute for external links
 	 */
-	public $mExternalLinkTarget;
+	private $mExternalLinkTarget;
 
 	/**
 	 * Clean up signature texts?
 	 * @see Parser::cleanSig
 	 */
-	public $mCleanSignatures;
+	private $mCleanSignatures;
 
 	/**
 	 * Transform wiki markup when saving the page?
 	 */
-	public $mPreSaveTransform = true;
+	private $mPreSaveTransform = true;
 
 	/**
 	 * Whether content conversion should be disabled
 	 */
-	public $mDisableContentConversion;
+	private $mDisableContentConversion;
 
 	/**
 	 * Whether title conversion should be disabled
 	 */
-	public $mDisableTitleConversion;
+	private $mDisableTitleConversion;
 
 	/**
 	 * Automatically number headings?
 	 */
-	public $mNumberHeadings;
+	private $mNumberHeadings;
 
 	/**
 	 * Thumb size preferred by the user.
 	 */
-	public $mThumbSize;
+	private $mThumbSize;
 
 	/**
 	 * Maximum article size of an article to be marked as "stub"
@@ -182,38 +182,38 @@ class ParserOptions {
 	/**
 	 * Language object of the User language.
 	 */
-	public $mUserLang;
+	private $mUserLang;
 
 	/**
 	 * @var User
 	 * Stored user object
 	 */
-	public $mUser;
+	private $mUser;
 
 	/**
 	 * Parsing the page for a "preview" operation?
 	 */
-	public $mIsPreview = false;
+	private $mIsPreview = false;
 
 	/**
 	 * Parsing the page for a "preview" operation on a single section?
 	 */
-	public $mIsSectionPreview = false;
+	private $mIsSectionPreview = false;
 
 	/**
 	 * Parsing the printable version of the page?
 	 */
-	public $mIsPrintable = false;
+	private $mIsPrintable = false;
 
 	/**
 	 * Extra key that should be present in the caching key.
 	 */
-	public $mExtraKey = '';
+	private $mExtraKey = '';
 
 	/**
 	 * Function to be called when an option is accessed.
 	 */
-	protected $onAccessCallback = null;
+	private $onAccessCallback = null;
 
 	/**
 	 * If the page being parsed is a redirect, this should hold the redirect
@@ -372,16 +372,17 @@ class ParserOptions {
 	}
 
 	/**
-	 * Get the user language used by the parser for this page.
+	 * Get the user language used by the parser for this page and split the parser cache.
 	 *
-	 * You shouldn't use this. Really. $parser->getFunctionLang() is all you need.
+	 * @warning: Calling this causes the parser cache to be fragmented by user language!
+	 * To avoid cache fragmentation, output should not depend on the user language.
+	 * Use Parser::getFunctionLang() or Parser::getTargetLanguage() instead!
 	 *
-	 * To avoid side-effects where the page will be rendered based on the language
-	 * of the user who last saved, this function will triger a cache fragmentation.
-	 * Usage of this method is discouraged for that reason.
-	 *
-	 * When saving, this will return the default language instead of the user's.
+	 * @note This function will trigger a cache fragmentation by recording the
+	 * 'userlang' option, see optionUsed(). This is done to avoid cache pollution
+	 * when the page is rendered based on the language of the user.
 	 *
+	 * @note When saving, this will return the default language instead of the user's.
 	 * {{int: }} uses this which used to produce inconsistent link tables (bug 14404).
 	 *
 	 * @return Language
@@ -395,6 +396,12 @@ class ParserOptions {
 	/**
 	 * Same as getUserLangObj() but returns a string instead.
 	 *
+	 * @warning: Calling this causes the parser cache to be fragmented by user language!
+	 * To avoid cache fragmentation, output should not depend on the user language.
+	 * Use Parser::getFunctionLang() or Parser::getTargetLanguage() instead!
+	 *
+	 * @see getUserLangObj()
+	 *
 	 * @return string Language code
 	 * @since 1.17
 	 */
@@ -700,6 +707,10 @@ class ParserOptions {
 
 	/**
 	 * Called when an option is accessed.
+	 * Calls the watcher that was set using registerWatcher().
+	 * Typically, the watcher callback is ParserOutput::registerOption().
+	 * The information registered that way will be used by ParserCache::save().
+	 *
 	 * @param string $optionName Name of the option
 	 */
 	public function optionUsed( $optionName ) {
@@ -791,6 +802,10 @@ class ParserOptions {
 
 		$confstr .= $wgRenderHashAppend;
 
+		// @note: as of Feb 2015, core never sets the editsection flag, since it uses
+		// <mw:editsection> tags to inject editsections on the fly. However, extensions
+		// may be using it by calling ParserOption::optionUsed resp. ParserOutput::registerOption
+		// directly. At least Wikibase does at this point in time.
 		if ( !in_array( 'editsection', $forOptions ) ) {
 			$confstr .= '!*';
 		} elseif ( !$this->mEditSection ) {
diff --git a/includes/parser/ParserOutput.php b/includes/parser/ParserOutput.php
index 65b527c8..2eb1dc9f 100644
--- a/includes/parser/ParserOutput.php
+++ b/includes/parser/ParserOutput.php
@@ -41,7 +41,6 @@ class ParserOutput extends CacheTime {
 		$mModules = array(),          # Modules to be loaded by the resource loader
 		$mModuleScripts = array(),    # Modules of which only the JS will be loaded by the resource loader
 		$mModuleStyles = array(),     # Modules of which only the CSSS will be loaded by the resource loader
-		$mModuleMessages = array(),   # Modules of which only the messages will be loaded by the resource loader
 		$mJsConfigVars = array(),     # JavaScript config variable for mw.config combined with this page
 		$mOutputHooks = array(),      # Hook tags as per $wgParserOutputHooks
 		$mWarnings = array(),         # Warning text to be returned to the user. Wikitext formatted, in the key only
@@ -50,7 +49,8 @@ class ParserOutput extends CacheTime {
 		$mProperties = array(),       # Name/value pairs to be cached in the DB
 		$mTOCHTML = '',               # HTML of the TOC
 		$mTimestamp,                  # Timestamp of the revision
-		$mTOCEnabled = true;          # Whether TOC should be shown, can't override __NOTOC__
+		$mTOCEnabled = true,          # Whether TOC should be shown, can't override __NOTOC__
+		$mEnableOOUI = false;         # Whether OOUI should be enabled
 	private $mIndexPolicy = '';       # 'index' or 'noindex'?  Any other value will result in no change.
 	private $mAccessedOptions = array(); # List of ParserOptions (stored in the keys)
 	private $mExtensionData = array(); # extra data used by extensions
@@ -104,7 +104,7 @@ class ParserOutput extends CacheTime {
 			$text = str_replace( array( Parser::TOC_START, Parser::TOC_END ), '', $text );
 		} else {
 			$text = preg_replace(
-				'#' . preg_quote( Parser::TOC_START ) . '.*?' . preg_quote( Parser::TOC_END ) . '#s',
+				'#' . preg_quote( Parser::TOC_START, '#' ) . '.*?' . preg_quote( Parser::TOC_END, '#' ) . '#s',
 				'',
 				$text
 			);
@@ -191,8 +191,13 @@ class ParserOutput extends CacheTime {
 		return $this->mModuleStyles;
 	}
 
+	/**
+	 * @deprecated since 1.26 Obsolete
+	 * @return array
+	 */
 	public function getModuleMessages() {
-		return $this->mModuleMessages;
+		wfDeprecated( __METHOD__, '1.26' );
+		return array();
 	}
 
 	/** @since 1.23 */
@@ -228,6 +233,10 @@ class ParserOutput extends CacheTime {
 		return $this->mTOCEnabled;
 	}
 
+	public function getEnableOOUI() {
+		return $this->mEnableOOUI;
+	}
+
 	public function setText( $text ) {
 		return wfSetVar( $this->mText, $text );
 	}
@@ -279,6 +288,17 @@ class ParserOutput extends CacheTime {
 		$this->mIndicators[$id] = $content;
 	}
 
+	/**
+	 * Enables OOUI, if true, in any OutputPage instance this ParserOutput
+	 * object is added to.
+	 *
+	 * @since 1.26
+	 * @param bool $enable If OOUI should be enabled or not
+	 */
+	public function setEnableOOUI( $enable = false ) {
+		$this->mEnableOOUI = $enable;
+	}
+
 	public function addLanguageLink( $t ) {
 		$this->mLanguageLinks[] = $t;
 	}
@@ -445,8 +465,12 @@ class ParserOutput extends CacheTime {
 		$this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 	}
 
+	/**
+	 * @deprecated since 1.26 Use addModules() instead
+	 * @param string|array $modules
+	 */
 	public function addModuleMessages( $modules ) {
-		$this->mModuleMessages = array_merge( $this->mModuleMessages, (array)$modules );
+		wfDeprecated( __METHOD__, '1.26' );
 	}
 
 	/**
@@ -476,7 +500,6 @@ class ParserOutput extends CacheTime {
 		$this->addModules( $out->getModules() );
 		$this->addModuleScripts( $out->getModuleScripts() );
 		$this->addModuleStyles( $out->getModuleStyles() );
-		$this->addModuleMessages( $out->getModuleMessages() );
 		$this->addJsConfigVars( $out->getJsConfigVars() );
 
 		$this->mHeadItems = array_merge( $this->mHeadItems, $out->getHeadItemsArray() );
@@ -663,6 +686,8 @@ class ParserOutput extends CacheTime {
 	/**
 	 * Tags a parser option for use in the cache key for this parser output.
 	 * Registered as a watcher at ParserOptions::registerWatcher() by Parser::clearState().
+	 * The information gathered here is available via getUsedOptions(),
+	 * and is used by ParserCache::save().
 	 *
 	 * @see ParserCache::getKey
 	 * @see ParserCache::save
diff --git a/includes/parser/Preprocessor_DOM.php b/includes/parser/Preprocessor_DOM.php
index 0351f2a8..8a09be83 100644
--- a/includes/parser/Preprocessor_DOM.php
+++ b/includes/parser/Preprocessor_DOM.php
@@ -87,9 +87,9 @@ class Preprocessor_DOM implements Preprocessor {
 		$xml .= "</list>";
 
 		$dom = new DOMDocument();
-		wfSuppressWarnings();
+		MediaWiki\suppressWarnings();
 		$result = $dom->loadXML( $xml );
-		wfRestoreWarnings();
+		MediaWiki\restoreWarnings();
 		if ( !$result ) {
 			// Try running the XML through UtfNormal to get rid of invalid characters
 			$xml = UtfNormal\Validator::cleanUp( $xml );
@@ -154,7 +154,6 @@ class Preprocessor_DOM implements Preprocessor {
 		$cacheable = ( $wgPreprocessorCacheThreshold !== false
 			&& strlen( $text ) > $wgPreprocessorCacheThreshold );
 		if ( $cacheable ) {
-
 			$cacheKey = wfMemcKey( 'preprocess-xml', md5( $text ), $flags );
 			$cacheValue = $wgMemc->get( $cacheKey );
 			if ( $cacheValue ) {
@@ -186,9 +185,9 @@ class Preprocessor_DOM implements Preprocessor {
 		}
 
 		$dom = new DOMDocument;
-		wfSuppressWarnings();
+		MediaWiki\suppressWarnings();
 		$result = $dom->loadXML( $xml );
-		wfRestoreWarnings();
+		MediaWiki\restoreWarnings();
 		if ( !$result ) {
 			// Try running the XML through UtfNormal to get rid of invalid characters
 			$xml = UtfNormal\Validator::cleanUp( $xml );
@@ -853,7 +852,8 @@ class PPDStackElement {
 		$close,             // Matching closing character
 		$count,             // Number of opening characters found (number of "=" for heading)
 		$parts,             // Array of PPDPart objects describing pipe-separated parts.
-		$lineStart;         // True if the open char appeared at the start of the input line. Not set for headings.
+		$lineStart;         // True if the open char appeared at the start of the input line.
+		                    // Not set for headings.
 
 	public $partClass = 'PPDPart';
 
@@ -1029,6 +1029,10 @@ class PPFrame_DOM implements PPFrame {
 					$index = $nameNodes->item( 0 )->attributes->getNamedItem( 'index' )->textContent;
 					$index = $index - $indexOffset;
 					if ( isset( $namedArgs[$index] ) || isset( $numberedArgs[$index] ) ) {
+						$this->parser->getOutput()->addWarning( wfMessage( 'duplicate-args-warning',
+							wfEscapeWikiText( $this->title ),
+							wfEscapeWikiText( $title ),
+							wfEscapeWikiText( $index ) )->text() );
 						$this->parser->addTrackingCategory( 'duplicate-args-category' );
 					}
 					$numberedArgs[$index] = $value->item( 0 );
@@ -1037,6 +1041,10 @@ class PPFrame_DOM implements PPFrame {
 					// Named parameter
 					$name = trim( $this->expand( $nameNodes->item( 0 ), PPFrame::STRIP_COMMENTS ) );
 					if ( isset( $namedArgs[$name] ) || isset( $numberedArgs[$name] ) ) {
+						$this->parser->getOutput()->addWarning( wfMessage( 'duplicate-args-warning',
+							wfEscapeWikiText( $this->title ),
+							wfEscapeWikiText( $title ),
+							wfEscapeWikiText( $name ) )->text() );
 						$this->parser->addTrackingCategory( 'duplicate-args-category' );
 					}
 					$namedArgs[$name] = $value->item( 0 );
@@ -1195,9 +1203,11 @@ class PPFrame_DOM implements PPFrame {
 				} elseif ( $contextNode->nodeName == 'comment' ) {
 					# HTML-style comment
 					# Remove it in HTML, pre+remove and STRIP_COMMENTS modes
-					if ( $this->parser->ot['html']
+					# Not in RECOVER_COMMENTS mode (msgnw) though.
+					if ( ( $this->parser->ot['html']
 						|| ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
 						|| ( $flags & PPFrame::STRIP_COMMENTS )
+						) && !( $flags & PPFrame::RECOVER_COMMENTS )
 					) {
 						$out .= '';
 					} elseif ( $this->parser->ot['wiki'] && !( $flags & PPFrame::RECOVER_COMMENTS ) ) {
@@ -1263,7 +1273,7 @@ class PPFrame_DOM implements PPFrame {
 						$titleText = $this->title->getPrefixedDBkey();
 						$this->parser->mHeadings[] = array( $titleText, $headingIndex );
 						$serial = count( $this->parser->mHeadings ) - 1;
-						$marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
+						$marker = Parser::MARKER_PREFIX . "-h-$serial-" . Parser::MARKER_SUFFIX;
 						$count = $contextNode->getAttribute( 'level' );
 						$s = substr( $s, 0, $count ) . $marker . substr( $s, $count );
 						$this->parser->mStripState->addGeneral( $marker, '' );
diff --git a/includes/parser/Preprocessor_Hash.php b/includes/parser/Preprocessor_Hash.php
index af91ad47..9429e442 100644
--- a/includes/parser/Preprocessor_Hash.php
+++ b/includes/parser/Preprocessor_Hash.php
@@ -112,7 +112,6 @@ class Preprocessor_Hash implements Preprocessor {
 	 * @return PPNode_Hash_Tree
 	 */
 	public function preprocessToObj( $text, $flags = 0 ) {
-
 		// Check cache.
 		global $wgMemc, $wgPreprocessorCacheThreshold;
 
@@ -120,7 +119,6 @@ class Preprocessor_Hash implements Preprocessor {
 			&& strlen( $text ) > $wgPreprocessorCacheThreshold;
 
 		if ( $cacheable ) {
-
 			$cacheKey = wfMemcKey( 'preprocess-hash', md5( $text ), $flags );
 			$cacheValue = $wgMemc->get( $cacheKey );
 			if ( $cacheValue ) {
@@ -736,8 +734,12 @@ class Preprocessor_Hash implements Preprocessor {
 		// Cache
 		if ( $cacheable ) {
 			$cacheValue = sprintf( "%08d", self::CACHE_VERSION ) . serialize( $rootNode );
-			$wgMemc->set( $cacheKey, $cacheValue, 86400 );
-			wfDebugLog( "Preprocessor", "Saved preprocessor Hash to memcached (key $cacheKey)" );
+
+			// T111289: Cache values should not exceed 1 Mb, but they do.
+			if ( strlen( $cacheValue ) <= 1e6 ) {
+				$wgMemc->set( $cacheKey, $cacheValue, 86400 );
+				wfDebugLog( "Preprocessor", "Saved preprocessor Hash to memcached (key $cacheKey)" );
+			}
 		}
 
 		return $rootNode;
@@ -972,6 +974,10 @@ class PPFrame_Hash implements PPFrame {
 					// Numbered parameter
 					$index = $bits['index'] - $indexOffset;
 					if ( isset( $namedArgs[$index] ) || isset( $numberedArgs[$index] ) ) {
+						$this->parser->getOutput()->addWarning( wfMessage( 'duplicate-args-warning',
+							wfEscapeWikiText( $this->title ),
+							wfEscapeWikiText( $title ),
+							wfEscapeWikiText( $index ) )->text() );
 						$this->parser->addTrackingCategory( 'duplicate-args-category' );
 					}
 					$numberedArgs[$index] = $bits['value'];
@@ -980,6 +986,10 @@ class PPFrame_Hash implements PPFrame {
 					// Named parameter
 					$name = trim( $this->expand( $bits['name'], PPFrame::STRIP_COMMENTS ) );
 					if ( isset( $namedArgs[$name] ) || isset( $numberedArgs[$name] ) ) {
+						$this->parser->getOutput()->addWarning( wfMessage( 'duplicate-args-warning',
+							wfEscapeWikiText( $this->title ),
+							wfEscapeWikiText( $title ),
+							wfEscapeWikiText( $name ) )->text() );
 						$this->parser->addTrackingCategory( 'duplicate-args-category' );
 					}
 					$namedArgs[$name] = $bits['value'];
@@ -1118,9 +1128,11 @@ class PPFrame_Hash implements PPFrame {
 				} elseif ( $contextNode->name == 'comment' ) {
 					# HTML-style comment
 					# Remove it in HTML, pre+remove and STRIP_COMMENTS modes
-					if ( $this->parser->ot['html']
+					# Not in RECOVER_COMMENTS mode (msgnw) though.
+					if ( ( $this->parser->ot['html']
 						|| ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
 						|| ( $flags & PPFrame::STRIP_COMMENTS )
+						) && !( $flags & PPFrame::RECOVER_COMMENTS )
 					) {
 						$out .= '';
 					} elseif ( $this->parser->ot['wiki'] && !( $flags & PPFrame::RECOVER_COMMENTS ) ) {
@@ -1177,7 +1189,7 @@ class PPFrame_Hash implements PPFrame {
 						$titleText = $this->title->getPrefixedDBkey();
 						$this->parser->mHeadings[] = array( $titleText, $bits['i'] );
 						$serial = count( $this->parser->mHeadings ) - 1;
-						$marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
+						$marker = Parser::MARKER_PREFIX . "-h-$serial-" . Parser::MARKER_SUFFIX;
 						$s = substr( $s, 0, $bits['level'] ) . $marker . substr( $s, $bits['level'] );
 						$this->parser->mStripState->addGeneral( $marker, '' );
 						$out .= $s;
diff --git a/includes/parser/StripState.php b/includes/parser/StripState.php
index 51ae42dc..b11dc8c3 100644
--- a/includes/parser/StripState.php
+++ b/includes/parser/StripState.php
@@ -37,15 +37,20 @@ class StripState {
 	const UNSTRIP_RECURSION_LIMIT = 20;
 
 	/**
-	 * @param string $prefix
+	 * @param string|null $prefix
+	 * @since 1.26 The prefix argument should be omitted, as the strip marker
+	 *  prefix string is now a constant.
 	 */
-	public function __construct( $prefix ) {
-		$this->prefix = $prefix;
+	public function __construct( $prefix = null ) {
+		if ( $prefix !== null ) {
+			wfDeprecated( __METHOD__ . ' with called with $prefix argument' .
+				' (call with no arguments instead)', '1.26' );
+		}
 		$this->data = array(
 			'nowiki' => array(),
 			'general' => array()
 		);
-		$this->regex = "/{$this->prefix}([^\x7f]+)" . Parser::MARKER_SUFFIX . '/';
+		$this->regex = '/' . Parser::MARKER_PREFIX . "([^\x7f]+)" . Parser::MARKER_SUFFIX . '/';
 		$this->circularRefGuard = array();
 	}
 
@@ -144,7 +149,11 @@ class StripState {
 			}
 			$this->circularRefGuard[$marker] = true;
 			$this->recursionLevel++;
-			$ret = $this->unstripType( $this->tempType, $this->data[$this->tempType][$marker] );
+			$value = $this->data[$this->tempType][$marker];
+			if ( $value instanceof Closure ) {
+				$value = $value();
+			}
+			$ret = $this->unstripType( $this->tempType, $value );
 			$this->recursionLevel--;
 			unset( $this->circularRefGuard[$marker] );
 			return $ret;
@@ -162,10 +171,10 @@ class StripState {
 	 * @return StripState
 	 */
 	public function getSubState( $text ) {
-		$subState = new StripState( $this->prefix );
+		$subState = new StripState();
 		$pos = 0;
 		while ( true ) {
-			$startPos = strpos( $text, $this->prefix, $pos );
+			$startPos = strpos( $text, Parser::MARKER_PREFIX, $pos );
 			$endPos = strpos( $text, Parser::MARKER_SUFFIX, $pos );
 			if ( $startPos === false || $endPos === false ) {
 				break;
@@ -198,7 +207,7 @@ class StripState {
 	 * @return array
 	 */
 	public function merge( $otherState, $texts ) {
-		$mergePrefix = Parser::getRandomString();
+		$mergePrefix = wfRandomString( 16 );
 
 		foreach ( $otherState->data as $type => $items ) {
 			foreach ( $items as $key => $value ) {
@@ -218,7 +227,7 @@ class StripState {
 	 */
 	protected function mergeCallback( $m ) {
 		$key = $m[1];
-		return "{$this->prefix}{$this->tempMergePrefix}-$key" . Parser::MARKER_SUFFIX;
+		return Parser::MARKER_PREFIX . $this->tempMergePrefix . '-' . $key . Parser::MARKER_SUFFIX;
 	}
 
 	/**