Index: includes/parser/Parser.php
===================================================================
--- includes/parser/Parser.php	(revision 46746)
+++ includes/parser/Parser.php	(working copy)
@@ -113,7 +113,8 @@
 		$ot,            // Shortcut alias, see setOutputType()
 		$mRevisionId,   // ID to display in {{REVISIONID}} tags
 		$mRevisionTimestamp, // The timestamp of the specified revision ID
-		$mRevIdForTs;   // The revision ID which was used to fetch the timestamp
+		$mRevIdForTs,   // The revision ID which was used to fetch the timestamp
+		$mParsing;      // Boolean to avoid/detect recursive parser calls
 
 	/**#@-*/
 
@@ -146,6 +147,7 @@
 		}
 		$this->mMarkerIndex = 0;
 		$this->mFirstCall = true;
+		$this->mParsing = false;
 	}
 
 	/**
@@ -194,7 +196,7 @@
 		$this->mLastSection = '';
 		$this->mDTopen = false;
 		$this->mIncludeCount = array();
-		$this->mStripState = new StripState;
+
+		#Explicitly assign by reference to avoid cloning errors
+		$this->mStripState =& new StripState;
 		$this->mArgStack = false;
 		$this->mInPre = false;
 		$this->mLinkHolders = new LinkHolderArray( $this );
@@ -241,6 +243,10 @@
 		wfProfileOut( __METHOD__ );
 	}
 
+	public function isParsing() {
+		return $this->mParsing;
+	}
+
 	function setOutputType( $ot ) {
 		$this->mOutputType = $ot;
 		// Shortcut alias
@@ -308,6 +314,11 @@
 		wfProfileIn( __METHOD__ );
 		wfProfileIn( $fname );
 
+		$wasParsing = $this->mParsing;
+		if( $wasParsing ) {
+			wfDebug( "$fname: Recursive call of ".__METHOD__."\n" );
+		}
+		$this->mParsing = true;
 		if ( $clearState ) {
 			$this->clearState();
 		}
@@ -427,6 +438,7 @@
 		$this->mOutput->setText( $text );
 		$this->mRevisionId = $oldRevisionId;
 		$this->mRevisionTimestamp = $oldRevisionTimestamp;
+		$this->mParsing = $wasParsing;
 		wfProfileOut( $fname );
 		wfProfileOut( __METHOD__ );
 
@@ -452,6 +464,11 @@
 	 */
 	function preprocess( $text, $title, $options, $revid = null ) {
 		wfProfileIn( __METHOD__ );
+		$wasParsing = $this->mParsing;
+		if( $wasParsing ) {
+			wfDebug( wfGetCaller().": Recursive call of ".__METHOD__."\n" );
+		}
+		$this->mParsing = true;
 		$this->clearState();
 		$this->setOutputType( self::OT_PREPROCESS );
 		$this->mOptions = $options;
@@ -463,6 +480,7 @@
 		wfRunHooks( 'ParserAfterStrip', array( &$this, &$text, &$this->mStripState ) );
 		$text = $this->replaceVariables( $text );
 		$text = $this->mStripState->unstripBoth( $text );
+		$this->mParsing = $wasParsing;
 		wfProfileOut( __METHOD__ );
 		return $text;
 	}
Index: includes/MessageCache.php
===================================================================
--- includes/MessageCache.php	(revision 46746)
+++ includes/MessageCache.php	(working copy)
@@ -647,12 +647,7 @@
 		return $message;
 	}
 
-	function transform( $message, $interface = false, $language = null ) {
-		// Avoid creating parser if nothing to transfrom
-		if( strpos( $message, '{{' ) === false ) {
-			return $message;
-		}
-
+	private function initParser() {
 		global $wgParser, $wgParserConf;
 		if ( !$this->mParser && isset( $wgParser ) ) {
 			# Do some initialisation so that we don't have to do it twice
@@ -664,14 +659,28 @@
 				$this->mParser = new $class( $wgParserConf );
 			} else {
 				$this->mParser = clone $wgParser;
+				$this->mParser->mParsing = false;
 			}
-			#wfDebug( __METHOD__ . ": following contents triggered transform: $message\n" );
 		}
+	}
+
+	public function getParser() {
+		$this->initParser();
+		return $this->mParser;
+	}
+
+	function transform( $message, $interface = false, $language = null ) {
+		// Avoid creating parser if nothing to transfrom
+		if( strpos( $message, '{{' ) === false ) {
+			return $message;
+		}
+		$this->initParser();
 		if ( $this->mParser ) {
 			$popts = $this->getParserOptions();
 			$popts->setInterfaceMessage( $interface );
 			$popts->setTargetLanguage( $language );
 			$message = $this->mParser->transformMsg( $message, $popts );
 		}
 		return $message;
 	}
Index: includes/OutputPage.php
===================================================================
--- includes/OutputPage.php	(revision 46746)
+++ includes/OutputPage.php	(working copy)
@@ -637,13 +637,17 @@
 	 * @param bool   $interface ??
 	 */
 	public function parse( $text, $linestart = true, $interface = false ) {
-		global $wgParser, $wgTitle;
+		global $wgParser, $wgTitle, $wgMessageCache;
 		if( is_null( $wgTitle ) ) {
 			throw new MWException( 'Empty $wgTitle in ' . __METHOD__ );
 		}
+		# If $wgParser is busy, use MessageCache's parser to avoid recursive calls
+		$parser = $wgParser->isParsing() && is_object( $wgMessageCache )
+			? $wgMessageCache->getParser()
+			: $wgParser;
 		$popts = $this->parserOptions();
 		if ( $interface) { $popts->setInterfaceMessage(true); }
-		$parserOutput = $wgParser->parse( $text, $wgTitle, $popts,
+		$parserOutput = $parser->parse( $text, $wgTitle, $popts,
 			$linestart, true, $this->mRevisionId );
 		if ( $interface) { $popts->setInterfaceMessage(false); }
 		return $parserOutput->getText();