handle non existing job classes in $jobList->getNext

lib/private/backgroundjob/joblist.php

@@ -87,6 +87,11 @@ class JobList implements IJobList {
 		}
 	}
 
+	protected function removeById($id) {
+		$query = $this->conn->prepare('DELETE FROM `*PREFIX*jobs` WHERE `id` = ?');
+		$query->execute([$id]);
+	}
+
 	/**
 	 * check if a job is in the list
 	 *
@@ -134,17 +139,25 @@ class JobList implements IJobList {
 		$query = $this->conn->prepare('SELECT `id`, `class`, `last_run`, `argument` FROM `*PREFIX*jobs` WHERE `id` > ? ORDER BY `id` ASC', 1);
 		$query->execute(array($lastId));
 		if ($row = $query->fetch()) {
-			return $this->buildJob($row);
+			$jobId = $row['id'];
+			$job = $this->buildJob($row);
 		} else {
 			//begin at the start of the queue
 			$query = $this->conn->prepare('SELECT `id`, `class`, `last_run`, `argument` FROM `*PREFIX*jobs` ORDER BY `id` ASC', 1);
 			$query->execute();
 			if ($row = $query->fetch()) {
-				return $this->buildJob($row);
+				$jobId = $row['id'];
+				$job = $this->buildJob($row);
 			} else {
 				return null; //empty job list
 			}
 		}
+		if (is_null($job)) {
+			$this->removeById($jobId);
+			return $this->getNext();
+		} else {
+			return $job;
+		}
 	}
 
 	/**

tests/lib/backgroundjob/joblist.php

@@ -202,4 +202,30 @@ class JobList extends \Test\TestCase {
 
 		$this->instance->remove($job);
 	}
+
+	public function testGetNextNonExisting() {
+		$job = new TestJob();
+		$this->instance->add($job, 1);
+		$this->instance->add('\OC\Non\Existing\Class');
+		$this->instance->add($job, 2);
+
+		$jobs = $this->instance->getAll();
+
+		$savedJob1 = $jobs[count($jobs) - 2];
+		$savedJob2 = $jobs[count($jobs) - 1];
+
+		$this->config->expects($this->any())
+			->method('getAppValue')
+			->with('backgroundjob', 'lastjob', 0)
+			->will($this->returnValue($savedJob1->getId()));
+
+		$this->instance->getNext();
+
+		$nextJob = $this->instance->getNext();
+
+		$this->assertEquals($savedJob2, $nextJob);
+
+		$this->instance->remove($job, 1);
+		$this->instance->remove($job, 2);
+	}
 }