Reverting prop=revisions diff generation: way too expensive and DoS-vulnerable

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 3018e5a..01d3e03 100644 (file)
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -86,7 +86,6 @@ it from source control: http://www.mediawiki.org/wiki/Download_from_SVN
 * Show a warning message when creating/editing a user (talk) page but the user
   does not exists
 * (bug 8396) Ignore out-of-date serialised message caches
-* (bug 943) RSS feed for Recentchangeslinked
 
 === Bug fixes in 1.12 ===
 
@@ -306,8 +305,6 @@ Full API documentation is available at http://www.mediawiki.org/wiki/API
 * Outputting list of all user preferences rather than having to request them by 
   name
 * (bug 11206) api.php should honor maxlag
-* Added diff generation to prop=revisions
-* Added support for traditional, unified and array diffs to prop=revisions
 * Make prop=info check for restrictions in the old format too.
 * Add apihighlimits permission, default for sysops and bots
 * Add limit=max to use maximal limit

diff --git a/includes/api/ApiQueryRevisions.php b/includes/api/ApiQueryRevisions.php
index dc75c21..1c14c87 100644 (file)
--- a/includes/api/ApiQueryRevisions.php
+++ b/includes/api/ApiQueryRevisions.php
@@ -45,14 +45,14 @@ class ApiQueryRevisions extends ApiQueryBase {
                        $fld_comment = false, $fld_user = false, $fld_content = false;
 
        public function execute() {
-               $limit = $startid = $endid = $start = $end = $dir = $prop = $user = $excludeuser = $diffto = $difftoprev = $diffformat = $token = null;
+               $limit = $startid = $endid = $start = $end = $dir = $prop = $user = $excludeuser = $token = null;
                extract($this->extractRequestParams());
 
                // If any of those parameters are used, work in 'enumeration' mode.
                // Enum mode can only be used when exactly one page is provided.
                // Enumerating revisions on multiple pages make it extremely 
                // difficult to manage continuations and require additional SQL indexes  
-               $enumRevMode = (!is_null($user) || !is_null($excludeuser) || !is_null($limit) || !is_null($startid) || !is_null($endid) || $dir === 'newer' || !is_null($start) || !is_null($end) | $difftoprev);
+               $enumRevMode = (!is_null($user) || !is_null($excludeuser) || !is_null($limit) || !is_null($startid) || !is_null($endid) || $dir === 'newer' || !is_null($start) || !is_null($end));
                
 
                $pageSet = $this->getPageSet();
@@ -67,7 +67,7 @@ class ApiQueryRevisions extends ApiQueryBase {
                        $this->dieUsage('The revids= parameter may not be used with the list options (limit, startid, endid, dirNewer, start, end).', 'revids');
 
                if ($pageCount > 1 && $enumRevMode)
-                       $this->dieUsage('titles, pageids or a generator was used to supply multiple pages, but the limit, startid, endid, dirNewer, user, excludeuser, start, end and difftoprev parameters may only be used on a single page.', 'multpages');
+                       $this->dieUsage('titles, pageids or a generator was used to supply multiple pages, but the limit, startid, endid, dirNewer, user, excludeuser, start and end parameters may only be used on a single page.', 'multpages');
 
                $this->addTables('revision');
                $this->addWhere('rev_deleted=0');
@@ -90,43 +90,6 @@ class ApiQueryRevisions extends ApiQueryBase {
                        $this->tok_rollback = $this->getTokenFlag($token, 'rollback');
                }
 
-               if($diffto || $difftoprev)
-                       switch($diffformat)
-                       {
-                               // To add your own formatter, create a subclass of DiffFormatter
-                               // in DifferenceEngine.php, then add it here
-                               case 'traditional':
-                                       $this->formatter = new DiffFormatter;
-                                       break;
-                               case 'unified':
-                                       $this->formatter = new UnifiedDiffFormatter;
-                                       break;
-                               case 'array':
-                                       $this->formatter = new ArrayDiffFormatter;
-                                       break;
-                       }
-               if($diffto)
-               {
-                       global $wgContLang;
-                       $difftoRev = Revision::newFromID($diffto);
-                       if(!($difftoRev instanceof Revision))
-                               $this->dieUsage("There is no revision with ID $diffto", 'nosuchrev');
-                       $this->diffOldText = $difftoRev->revText();
-                       if($this->diffOldText == '') // deleted revision
-                               $this->dieUsage("There is no revision with ID $diffto", 'nosuchrev'); // fake non-existence
-                       $this->diffOldText = explode("\n", $wgContLang->segmentForDiff($this->diffOldText));
-                       $this->diffto = $diffto;
-               }
-               else
-                       $this->diffto = false;
-               if($difftoprev)
-               {
-                       $this->revCache = array();
-                       $this->difftoprev = true;
-               }
-               else
-                       $this->difftoprev = false;
-
                if (isset ($prop['user'])) {
                        $this->addFields('rev_user');
                        $this->addFields('rev_user_text');
@@ -135,7 +98,7 @@ class ApiQueryRevisions extends ApiQueryBase {
                else if($this->tok_rollback)
                        $this->addFields('rev_user_text');
                
-               if (isset ($prop['content']) || !is_null($diffto) || $difftoprev) {
+               if (isset ($prop['content'])) {
 
                        // For each page we will request, the user must have read rights for that page
                        foreach ($pageSet->getGoodTitles() as $title) {
@@ -151,13 +114,13 @@ class ApiQueryRevisions extends ApiQueryBase {
                        $this->addFields('old_text');
                        $this->addFields('old_flags');
 
-                       $this->fld_content = isset($prop['content']);
+                       $this->fld_content = true;
                        
                        $this->expandTemplates = $expandtemplates;
                }
 
-               $userMax = ($this->fld_content || $diffto || $difftoprev ? 50 : 500);
-               $botMax = ($this->fld_content || $diffto || $difftoprev ? 200 : 10000);
+               $userMax = ($this->fld_content ? 50 : 500);
+               $botMax = ($this->fld_content ? 200 : 10000);
 
                if ($enumRevMode) {
 
@@ -250,54 +213,6 @@ class ApiQueryRevisions extends ApiQueryBase {
                }
                $db->freeResult($res);
                
-               if($this->difftoprev)
-               {
-                       global $wgContLang;
-                       ksort($this->revCache, SORT_NUMERIC);
-                       $previousRevID = null;
-                       $oldText = null;
-                       $data =& $this->getResult()->getData();
-                       $pageID = current(array_keys($pageSet->getGoodTitles()));
-                       $this->diffArr = array();
-                       foreach($this->revCache as $revid => $revtext)
-                       {
-                               $r = array();
-                               if(is_null($previousRevID))
-                               {
-                                       // First run
-                                       $previousRevID = $revid;
-                                       $oldText = explode("\n", $wgContLang->segmentForDiff($revtext));                                        
-                                       continue;
-                               }
-                               $newText = explode("\n", $wgContLang->segmentForDiff($revtext));
-                               $diff = new Diff($oldText, $newText);
-                               $r['from'] = $previousRevID;
-                               $formatted = $this->formatter->format($diff);
-                               if(!is_array($formatted))
-                                       ApiResult::setContent($r, $wgContLang->unsegmentForDiff($this->formatter->format($diff)));
-                               else
-                               {
-                                       $r['differences'] = $formatted;
-                                       $this->getResult()->setIndexedTagName($r['differences'], 'diff');
-                               } 
-                               $this->diffArr[$revid] = $r;
-                                                               
-                               $previousRevID = $revid;
-                               $oldText = $newText;
-                       }
-
-                       if ( $this->diffArr ) {
-                               # Populate the query result with the contents of $this->diffArr.
-                               $knownrevs = array_keys($this->diffArr);
-                               $i = count($knownrevs) - 1;
-                               foreach($data['query']['pages'][$pageID]['revisions'] as &$rev) {
-                                       if ( $i >= 0 && isset ( $this->diffArr[$knownrevs[$i]] ) )
-                                               $rev['difftoprev'] = $this->diffArr[$knownrevs[$i]];
-                                       $i --;
-                               }
-                       }
-               }
-               
                // Ensure that all revisions are shown as '<rev>' elements
                $result = $this->getResult();
                if ($result->getIsRawMode()) {
@@ -348,35 +263,15 @@ class ApiQueryRevisions extends ApiQueryBase {
                        $vals['rollbacktoken'] = $wgUser->editToken(array($title->getPrefixedText(), $row->rev_user_text));
                }
                
-               if ($this->fld_content || $this->diffto || $this->difftoprev)
-                       $text = Revision :: getRevisionText($row);
+               
                if ($this->fld_content) {
+                       $text = Revision :: getRevisionText($row);                      
                        if ($this->expandTemplates) {
                                global $wgParser;
                                $text = $wgParser->preprocess( $text, $title, new ParserOptions() );
                        }
                        ApiResult :: setContent($vals, $text);
-               }
-               
-               if($this->diffto)
-               {
-                       global $wgContLang;
-                       $newText = explode("\n", $wgContLang->segmentForDiff($text));
-                       $diff = new Diff($this->diffOldText, $newText);
-                       $vals['diffto']['from'] = $this->diffto;
-                       $arraydiff = $this->formatter instanceof ArrayDiffFormatter;
-                       if( $arraydiff ) {
-                               $changes = $wgContLang->unsegmentForDiff($this->formatter->format($diff));
-                               $this->getResult()->setIndexedTagName( $changes, 'change' );
-                               $vals['diffto'] = $changes;
-                       } else {
-                               ApiResult::setContent($vals['diffto'], $wgContLang->unsegmentForDiff($this->formatter->format($diff)));
-                       }
-               }
-               if($this->difftoprev)
-                       // Cache the revision's content for later use
-                       $this->revCache[$row->rev_id] = $text;
-               
+               }               
                return $vals;
        }
 
@@ -428,18 +323,6 @@ class ApiQueryRevisions extends ApiQueryBase {
                        ),
                        
                        'expandtemplates' => false,
-                       'diffto' => array(
-                               ApiBase :: PARAM_TYPE => 'integer'
-                       ),
-                       'difftoprev' => false,
-                       'diffformat' => array(
-                               ApiBase :: PARAM_TYPE => array(
-                                       'traditional',
-                                       'unified',
-                                       'array',
-                               ),
-                               ApiBase :: PARAM_DFLT => 'unified'
-                       ),
                        'token' => array(
                                ApiBase :: PARAM_TYPE => array(
                                        'rollback'
@@ -461,9 +344,6 @@ class ApiQueryRevisions extends ApiQueryBase {
                        'user' => 'only include revisions made by user',
                        'excludeuser' => 'exclude revisions made by user',
                        'expandtemplates' => 'expand templates in revision content',
-                       'diffto' => 'Revision number to compare all revisions with',
-                       'difftoprev' => 'Diff each revision to the previous one (enum)',
-                       'diffformat' => 'Format to use for diffs',
                        'token' => 'Which tokens to obtain for each revision',
                );
        }