Fix TimerDeathPenalty not properly handling negative/infinite timeout (#1845)

* Fix TimerDeathPenalty not properly handling negative/infinite timeout

* revert back to using exc_info

---------

Co-authored-by: Marcus <marcus@us2.ai>

rq/timeouts.py

@@ -110,10 +110,14 @@ class TimerDeathPenalty(BaseDeathPenalty):
 
     def setup_death_penalty(self):
         """Starts the timer."""
+        if self._timeout <= 0:
+            return
         self._timer = self.new_timer()
         self._timer.start()
 
     def cancel_death_penalty(self):
         """Cancels the timer."""
+        if self._timeout <= 0:
+            return
         self._timer.cancel()
         self._timer = None

tests/test_timeouts.py

@@ -42,3 +42,10 @@ class TestTimeouts(RQTestCase):
         self.assertIn(job, failed_job_registry)
         job.refresh()
         self.assertIn("rq.timeouts.JobTimeoutException", job.exc_info)
+
+        # Test negative timeout doesn't raise JobTimeoutException,
+        # which implies an unintended immediate timeout.
+        job = q.enqueue(thread_friendly_sleep_func, args=(1,), job_timeout=-1)
+        w.work(burst=True)
+        job.refresh()
+        self.assertIn(job, finished_job_registry)