Fix - TypeError - accessing None when dequeued result is None (when timeout=None, e.g. in burst mode) (#1793)

* fix accessing None when dequeued result is None (burst=True, or timeout=None)

* add a test

* pr fix

* fix tests

rq/worker.py

@@ -757,8 +757,8 @@ class Worker:
                     serializer=self.serializer,
                 )
                 if result is not None:
-                    self.log.debug(f"Dequeued job {blue(result[0].id)} from {green(result[1].name)}")
                     job, queue = result
+                    self.log.debug(f"Dequeued job {blue(job.id)} from {green(queue.name)}")
                     job.redis_server_version = self.get_redis_server_version()
                     if self.log_job_description:
                         self.log.info('%s: %s (%s)', green(queue.name), blue(job.description), job.id)

tests/test_worker.py

@@ -634,6 +634,14 @@ class TestWorker(RQTestCase):
         res.refresh()
         self.assertIn('JobTimeoutException', as_text(res.exc_info))
 
+    def test_dequeue_job_and_maintain_ttl_non_blocking(self):
+        """Not passing a timeout should return immediately with None as a result"""
+        q = Queue()
+        w = Worker([q])
+
+        # Put it on the queue with a timeout value
+        self.assertIsNone(w.dequeue_job_and_maintain_ttl(None))
+
     def test_worker_sets_result_ttl(self):
         """Ensure that Worker properly sets result_ttl for individual jobs."""
         q = Queue()