(bug 934) List each category on a page only once.

Dan Keshet's patch (http://bugzilla.wikipedia.org/attachment.cgi?id=134&action=view) plus an added version check on parser cache objects, to automatically discard cached objects using the incompatible older format.

diff --git a/includes/Parser.php b/includes/Parser.php
index 568bb21..e17ad5a 100644 (file)
--- a/includes/Parser.php
+++ b/includes/Parser.php
@@ -7,6 +7,13 @@
  * @version $Id$
  */
 
+/**
+ * Update this version number when the ParserOutput format
+ * changes in an incompatible way, so the parser cache
+ * can automatically discard old data.
+ */
+define( 'MW_PARSER_VERSION', '1.4.0' );
+
 /**
  * Variable substitution O(N^2) attack
  *
@@ -1323,7 +1330,7 @@ class Parser
                                                $sortkey = $text;
                                        }
                                        $wgLinkCache->addCategoryLinkObj( $nt, $sortkey );
-                                       $this->mOutput->mCategoryLinks[] = $t ;
+                                       $this->mOutput->addCategoryLink( $t );
                                        $s .= $prefix . $trail ;
                                        
                                        wfProfileOut( "$fname-category" );
@@ -3063,6 +3070,7 @@ class ParserOutput
 {
        var $mText, $mLanguageLinks, $mCategoryLinks, $mContainsOldMagic;
        var $mCacheTime; # Used in ParserCache
+       var $mVersion;   # Compatibility check
 
        function ParserOutput( $text = '', $languageLinks = array(), $categoryLinks = array(),
                $containsOldMagic = false )
@@ -3072,11 +3080,12 @@ class ParserOutput
                $this->mCategoryLinks = $categoryLinks;
                $this->mContainsOldMagic = $containsOldMagic;
                $this->mCacheTime = '';
+               $this->mVersion = MW_PARSER_VERSION;
        }
 
        function getText()                   { return $this->mText; }
        function getLanguageLinks()          { return $this->mLanguageLinks; }
-       function getCategoryLinks()          { return $this->mCategoryLinks; }
+       function getCategoryLinks()          { return array_keys( $this->mCategoryLinks ); }
        function getCacheTime()              { return $this->mCacheTime; }
        function containsOldMagic()          { return $this->mContainsOldMagic; }
        function setText( $text )            { return wfSetVar( $this->mText, $text ); }
@@ -3084,6 +3093,7 @@ class ParserOutput
        function setCategoryLinks( $cl )     { return wfSetVar( $this->mCategoryLinks, $cl ); }
        function setContainsOldMagic( $com ) { return wfSetVar( $this->mContainsOldMagic, $com ); }
        function setCacheTime( $t )          { return wfSetVar( $this->mCacheTime, $t ); }
+       function addCategoryLink( $c )       { $this->mCategoryLinks[$c] = 1; }
 
        function merge( $other ) {
                $this->mLanguageLinks = array_merge( $this->mLanguageLinks, $other->mLanguageLinks );
@@ -3091,6 +3101,22 @@ class ParserOutput
                $this->mContainsOldMagic = $this->mContainsOldMagic || $other->mContainsOldMagic;
        }
 
+       /**
+        * Return true if this cached output object predates the global or
+        * per-article cache invalidation timestamps, or if it comes from
+        * an incompatible older version.
+        *
+        * @param string $touched the affected article's last touched timestamp
+        * @return bool
+        * @access public
+        */
+       function expired( $touched ) {
+               global $wgCacheEpoch;
+               return $this->getCacheTime() <= $touched ||
+                      $this->getCacheTime() <= $wgCacheEpoch ||
+                      !isset( $this->mVersion ) ||
+                      version_compare( $this->mVersion, MW_PARSER_VERSION, "lt" );
+       }
 }
 
 /**

diff --git a/includes/ParserCache.php b/includes/ParserCache.php
index fce8ed3..00ed003 100644 (file)
--- a/includes/ParserCache.php
+++ b/includes/ParserCache.php
@@ -43,7 +43,7 @@ class ParserCache {
                        $canCache = $article->checkTouched();
                        $cacheTime = $value->getCacheTime();
                        $touched = $article->mTouched;
-                       if ( !$canCache || $value->getCacheTime() <= $touched || $cacheTime < $wgCacheEpoch ) {
+                       if ( !$canCache || $value->expired( $touched ) ) {
                                if ( !$canCache ) {
                                        wfDebug( "Invalid cached redirect, touched $touched, epoch $wgCacheEpoch, cached $cacheTime\n" );
                                } else {