From 985a2664a4099b192de877c9dfc824d36b43f48e Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@gmail.com>
Date: Mon, 16 Mar 2015 23:30:41 -0700
Subject: [PATCH 1/2] Prevent `Queue#dequeue` from blowing the stack

In the case of many sequential jobs having been deleted, a recursive
implementation of `Queue#dequeue` is prone to blowing the stack in the
absence of tail-recursion support. Change the implementation from
recursive to iterative to work around this issue in CPython.
---
 rq/queue.py         | 32 ++++++++++++++++----------------
 tests/test_queue.py |  8 ++++++++
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/rq/queue.py b/rq/queue.py
index ea39d81f..baf16d61 100644
--- a/rq/queue.py
+++ b/rq/queue.py
@@ -329,22 +329,22 @@ class Queue(object):
 
         Returns a job_class instance, which can be executed or inspected.
         """
-        job_id = self.pop_job_id()
-        if job_id is None:
-            return None
-        try:
-            job = self.job_class.fetch(job_id, connection=self.connection)
-        except NoSuchJobError as e:
-            # Silently pass on jobs that don't exist (anymore),
-            # and continue by reinvoking itself recursively
-            return self.dequeue()
-        except UnpickleError as e:
-            # Attach queue information on the exception for improved error
-            # reporting
-            e.job_id = job_id
-            e.queue = self
-            raise e
-        return job
+        while True:
+            job_id = self.pop_job_id()
+            if job_id is None:
+                return None
+            try:
+                job = self.job_class.fetch(job_id, connection=self.connection)
+            except NoSuchJobError as e:
+                # Silently pass on jobs that don't exist (anymore),
+                continue
+            except UnpickleError as e:
+                # Attach queue information on the exception for improved error
+                # reporting
+                e.job_id = job_id
+                e.queue = self
+                raise e
+            return job
 
     @classmethod
     def dequeue_any(cls, queues, timeout, connection=None):
diff --git a/tests/test_queue.py b/tests/test_queue.py
index e4e92537..6a631d7d 100644
--- a/tests/test_queue.py
+++ b/tests/test_queue.py
@@ -173,6 +173,14 @@ class TestQueue(RQTestCase):
         # ...and assert the queue count when down
         self.assertEquals(q.count, 0)
 
+    def test_dequeue_deleted_jobs(self):
+        """Dequeueing deleted jobs from queues don't blow the stack."""
+        q = Queue()
+        for _ in range(1,1000):
+            job = q.enqueue(say_hello)
+            job.delete()
+        q.dequeue()
+
     def test_dequeue_instance_method(self):
         """Dequeueing instance method jobs from queues."""
         q = Queue()

From a37621a429f4598be6bfd1eb9332b761d351df46 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@gmail.com>
Date: Mon, 16 Mar 2015 23:38:56 -0700
Subject: [PATCH 2/2] Switch to Travis container-based infrastructure

---
 .travis.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.travis.yml b/.travis.yml
index 9d3d1108..0a9a69ef 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,4 @@
+sudo: false
 language: python
 services:
   - redis