From 79303cd93a877d2edd33e9efeafd78e532dd3226 Mon Sep 17 00:00:00 2001
From: Jens Frank <jeluf@users.mediawiki.org>
Date: Sat, 28 Aug 2004 23:00:04 +0000
Subject: [PATCH] ENH#59 Provide a (diff) link in Special:Contributions Does
 not look up the next old revision for every change but links to
 pseudo-revision 'prev'. DifferenceEngine looks up the previous revision if
 user requests a specific diff.

---
 includes/Article.php              |  2 +-
 includes/Database.php             |  2 +-
 includes/DifferenceEngine.php     | 15 +++++++++++++--
 includes/SpecialContributions.php | 15 ++++++++++-----
 4 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/includes/Article.php b/includes/Article.php
index 3bde806606..9530bd02df 100644
--- a/includes/Article.php
+++ b/includes/Article.php
@@ -663,7 +663,7 @@ class Article {
 		if ( !is_null( $diff ) ) {
 			require_once( 'DifferenceEngine.php' );
 			$wgOut->setPageTitle( $this->mTitle->getPrefixedText() );
-			$de = new DifferenceEngine( intval($oldid), intval($diff), intval($rcid) );
+			$de = new DifferenceEngine( $oldid, $diff, $rcid );
 			$de->showDiffPage();
 			wfProfileOut( $fname );
 			if( $diff == 0 ) {
diff --git a/includes/Database.php b/includes/Database.php
index ac3f06ec14..acfab2bb90 100644
--- a/includes/Database.php
+++ b/includes/Database.php
@@ -326,7 +326,7 @@ class Database {
 		return !!$this->query( $sql, DB_MASTER, $fname );
 	}
 	
-	function getField( $table, $var, $cond='', $fname = 'Database::get', $options = array() ) {
+	function getField( $table, $var, $cond='', $fname = 'Database::getField', $options = array() ) {
 		return $this->selectField( $table, $var, $cond, $fname = 'Database::get', $options = array() );
 	}
 
diff --git a/includes/DifferenceEngine.php b/includes/DifferenceEngine.php
index 94a310223a..5241c4b75f 100644
--- a/includes/DifferenceEngine.php
+++ b/includes/DifferenceEngine.php
@@ -12,8 +12,19 @@ class DifferenceEngine {
 
 	function DifferenceEngine( $old, $new, $rcid = 0 )
 	{
-		$this->mOldid = $old;
-		$this->mNewid = $new;
+		global $wgTitle;
+		if ( 'prev' == $new ) {
+			$this->mNewid = intval($old);
+			$dbr =& wfGetDB( DB_SLAVE );
+			$this->mOldid = $dbr->selectField( 'old', 'old_id',  
+				"old_title='" . $wgTitle->getDBkey() . "'" .
+				' AND old_namespace=' . $wgTitle->getNamespace() .
+				" AND old_id<{$this->mNewid} order by old_id desc" );
+
+		} else {
+			$this->mOldid = intval($old);
+			$this->mNewid = intval($new);
+		}
 		$this->mRcidMarkPatrolled = intval($rcid);  # force it to be an integer
 	}
 
diff --git a/includes/SpecialContributions.php b/includes/SpecialContributions.php
index ca909f9935..78bd35c8a9 100644
--- a/includes/SpecialContributions.php
+++ b/includes/SpecialContributions.php
@@ -75,7 +75,7 @@ function wfSpecialContributions( $par = "" )
 		  "ORDER BY inverse_timestamp LIMIT {$querylimit}";
 		$res1 = $dbr->query( $sql, $fname );
 
-		$sql = "SELECT old_namespace,old_title,old_timestamp,old_comment,old_minor_edit,old_user_text FROM $old " .
+		$sql = "SELECT old_namespace,old_title,old_timestamp,old_comment,old_minor_edit,old_user_text,old_id FROM $old " .
 		  "WHERE old_user_text='" . $dbr->strencode( $nt->getText() ) . "' {$omq} " .
 		  "ORDER BY inverse_timestamp LIMIT {$querylimit}";
 		$res2 = $dbr->query( $sql, $fname );
@@ -84,7 +84,7 @@ function wfSpecialContributions( $par = "" )
 		  "WHERE cur_user {$userCond} {$cmq} ORDER BY inverse_timestamp LIMIT {$querylimit}";
 		$res1 = $dbr->query( $sql, $fname );
 
-		$sql = "SELECT old_namespace,old_title,old_timestamp,old_comment,old_minor_edit,old_user_text FROM $old " .
+		$sql = "SELECT old_namespace,old_title,old_timestamp,old_comment,old_minor_edit,old_user_text,old_id FROM $old " .
 		  "WHERE old_user {$userCond} {$omq} ORDER BY inverse_timestamp LIMIT {$querylimit}";
 		$res2 = $dbr->query( $sql, $fname );
 	}
@@ -127,6 +127,7 @@ function wfSpecialContributions( $par = "" )
 
 			$obj1 = $dbr->fetchObject( $res1 );
 			$topmark = true;
+			$oldid = false;
 			--$nCur;
 		} else {
 			$ns = $obj2->old_namespace;
@@ -135,6 +136,7 @@ function wfSpecialContributions( $par = "" )
 			$comment =$obj2->old_comment;
 			$me = $obj2->old_minor_edit;
 			$usertext = $obj2->old_user_text;
+			$oldid = $obj2->old_id;
 
 			$obj2 = $dbr->fetchObject( $res2 );
 			$topmark = false;
@@ -142,7 +144,7 @@ function wfSpecialContributions( $par = "" )
 			--$nOld;
 		}
 		if( $n >= $offset )
-			ucListEdit( $sk, $ns, $t, $ts, $topmark, $comment, ( $me > 0), $isnew, $usertext );
+			ucListEdit( $sk, $ns, $t, $ts, $topmark, $comment, ( $me > 0), $isnew, $usertext, $oldid );
 	}
 	$wgOut->addHTML( "</ul>\n" );
 
@@ -175,7 +177,7 @@ other users.
 TODO: This would probably look a lot nicer in a table.
 
 */
-function ucListEdit( $sk, $ns, $t, $ts, $topmark, $comment, $isminor, $isnew, $target )
+function ucListEdit( $sk, $ns, $t, $ts, $topmark, $comment, $isminor, $isnew, $target, $oldid )
 {
 	global $wgLang, $wgOut, $wgUser, $wgRequest;
 	$page = Title::makeName( $ns, $t );
@@ -197,6 +199,9 @@ function ucListEdit( $sk, $ns, $t, $ts, $topmark, $comment, $isminor, $isnew, $t
 		}
 
 	}
+	if ( $oldid ) {
+		$oldtext= $sk->makeKnownLink( $page, '('.wfMsg('diff').')', 'diff=prev&oldid='.$oldid );
+	} else { $oldtext=''; }
 	$histlink="(".$sk->makeKnownLink($page,wfMsg("hist"),"action=history").")";
 
 	if($comment) {
@@ -212,7 +217,7 @@ function ucListEdit( $sk, $ns, $t, $ts, $topmark, $comment, $isminor, $isnew, $t
 		$mflag = "";
 	}
 
-	$wgOut->addHTML( "<li>{$d} {$histlink} {$mflag} {$link} {$comment}{$topmarktext}</li>\n" );
+	$wgOut->addHTML( "<li>{$d} {$histlink} {$mflag} {$link} {$comment}{$topmarktext}{$oldtext}</li>\n" );
 }
 
 function ucCountLink( $lim, $d )
-- 
2.20.1