From 186f6c4d5eac0545267310ce2ccd13553d230001 Mon Sep 17 00:00:00 2001
From: Jens Frank <jeluf@users.mediawiki.org>
Date: Sat, 2 Oct 2004 19:49:54 +0000
Subject: [PATCH] Moved 'get previous/next revision' code from DifferenceEngine
 to Title'

---
 includes/DifferenceEngine.php | 23 +++++++++++++----------
 includes/Title.php            | 29 +++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/includes/DifferenceEngine.php b/includes/DifferenceEngine.php
index 198c9b3931..9276d0f058 100644
--- a/includes/DifferenceEngine.php
+++ b/includes/DifferenceEngine.php
@@ -25,11 +25,13 @@ class DifferenceEngine {
 			# Get previous one from DB.
 			#
 			$this->mNewid = intval($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" );
+
+			$this->mOldid = $wgTitle->getPreviousRevisionID( $this->mNewid );
+			#$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" );
 
 		} elseif ( 'next' == $new ) {
 
@@ -37,11 +39,12 @@ class DifferenceEngine {
 			# Get previous one from DB.
 			#
 			$this->mOldid = intval($old);
-			$dbr =& wfGetDB( DB_SLAVE );
-			$this->mNewid = $dbr->selectField( 'old', 'old_id',
-				"old_title='" . $wgTitle->getDBkey() . "'" .
-				' AND old_namespace=' . $wgTitle->getNamespace() .
-				" AND old_id>{$this->mOldid} ORDER BY old_id " );
+			$this->mNewid = $wgTitle->getNextRevisionID( $this->mOldid );
+			#$dbr =& wfGetDB( DB_SLAVE );
+			#$this->mNewid = $dbr->selectField( 'old', 'old_id',
+			#	"old_title='" . $wgTitle->getDBkey() . "'" .
+			#	' AND old_namespace=' . $wgTitle->getNamespace() .
+			#	" AND old_id>{$this->mOldid} ORDER BY old_id " );
 			if ( false === $this->mNewid ) {
 				# if no result, NewId points to the newest old revision. The only newer
 				# revision is cur, which is "0".
diff --git a/includes/Title.php b/includes/Title.php
index 94da807b41..4adec439e2 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -1698,5 +1698,34 @@ class Title {
 	function oldCond() {
 		return array( 'old_namespace' => $this->mNamespace, 'old_title' => $this->mDbkeyform );
 	}
+
+	/**
+	 * Get the revision ID of the previous revision
+	 *
+	 * @param integer $revision  Revision ID. Get the revision that was before this one.
+	 * @return interger $oldrevision|false
+	 */
+	function getPreviousRevisionID( $revision ) {
+		$dbr =& wfGetDB( DB_SLAVE );
+		return $dbr->selectField( 'old', 'old_id',
+			"old_title='" . $this->getDBkey() . "'" .
+			' AND old_namespace=' . $this->getNamespace() .
+			" AND old_id<{$revision} ORDER BY old_id DESC" );
+	}
+
+	/**
+	 * Get the revision ID of the next revision
+	 *
+	 * @param integer $revision  Revision ID. Get the revision that was after this one.
+	 * @return interger $oldrevision|false
+	 */
+	function getNextRevisionID( $revision ) {
+		$dbr =& wfGetDB( DB_SLAVE );
+		return $dbr->selectField( 'old', 'old_id',
+			"old_title='" . $this->getDBkey() . "'" .
+			' AND old_namespace=' . $this->getNamespace() .
+			" AND old_id>{$revision} ORDER BY old_id" );
+	}
+
 }
 ?>
-- 
2.20.1