From 005f53fe15f46dd228917077730e56ca537534f0 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Thu, 10 Mar 2011 11:39:23 +0000
Subject: [PATCH] Fix duplicate removal. Was completely broken, with a "job_id
 IS NULL" condition in the delete query. Added a COMMIT to pop_type().

---
 includes/job/JobQueue.php | 40 +++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/includes/job/JobQueue.php b/includes/job/JobQueue.php
index 949dfe542d..517b94fa5f 100644
--- a/includes/job/JobQueue.php
+++ b/includes/job/JobQueue.php
@@ -68,6 +68,7 @@ abstract class Job {
 		/* Ensure we "own" this row */
 		$dbw->delete( 'job', array( 'job_id' => $row->job_id ), __METHOD__ );
 		$affected = $dbw->affectedRows();
+		$dbw->commit();
 
 		if ( $affected == 0 ) {
 			wfProfileOut( __METHOD__ );
@@ -81,13 +82,7 @@ abstract class Job {
 		$job = Job::factory( $row->job_cmd, $title, Job::extractBlob( $row->job_params ),
 			$row->job_id );
 
-		$dbw->delete( 'job', $job->insertFields(), __METHOD__ );
-		$affected = $dbw->affectedRows();
-		$dbw->commit();
-
-		if ( $affected ) {
-			wfIncrStats( 'job-dup-delete', $affected );
-		}
+		$job->removeDuplicates();
 
 		wfProfileOut( __METHOD__ );
 		return $job;
@@ -176,15 +171,7 @@ abstract class Job {
 		$job = Job::factory( $row->job_cmd, $title, Job::extractBlob( $row->job_params ), $row->job_id );
 
 		// Remove any duplicates it may have later in the queue
-		// Deadlock prone section
-		$dbw->begin();
-		$dbw->delete( 'job', $job->insertFields(), __METHOD__ );
-		$affected = $dbw->affectedRows();
-		$dbw->commit();
-
-		if ( $affected ) {
-			wfIncrStats( 'job-dup-delete', $affected );
-		}
+		$job->removeDuplicates();
 
 		wfProfileOut( __METHOD__ );
 		return $job;
@@ -308,6 +295,27 @@ abstract class Job {
 		);
 	}
 
+	/**
+	 * Remove jobs in the job queue which are duplicates of this job.
+	 * This is deadlock-prone and so starts its own transaction.
+	 */
+	function removeDuplicates() {
+		if ( !$this->removeDuplicates ) {
+			return;
+		}
+
+		$fields = $this->insertFields();
+		unset( $fields['job_id'] );
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->begin();
+		$dbw->delete( 'job', $fields, __METHOD__ );
+		$affected = $dbw->affectedRows();
+		$dbw->commit();
+		if ( $affected ) {
+			wfIncrStats( 'job-dup-delete', $affected );
+		}
+	}
+
 	function toString() {
 		$paramString = '';
 		if ( $this->params ) {
-- 
2.20.1