AMQP result backend result.get(): Wait for next state if state is not in READY_STATES.

celery/backends/amqp.py

@@ -116,8 +116,12 @@ class AMQPBackend(BaseDictBackend):
         return self.poll(task_id)
 
     def wait_for(self, task_id, timeout=None, cache=True):
+        time_start = time()
         if task_id in self._cache:
-            meta = self._cache[task_id]
+            cached_meta = self._cache[task_id]
+
+        if cached_meta and cached_meta["status"] in states.READY_STATES:
+            meta = cached_meta
         else:
             try:
                 meta = self.consume(task_id, timeout=timeout)
@@ -128,6 +132,9 @@ class AMQPBackend(BaseDictBackend):
             return meta["result"]
         elif meta["status"] in states.PROPAGATE_STATES:
             raise self.exception_to_python(meta["result"])
+        else:
+            return self.wait_for(task_id, timeout, cache)
+
 
     def poll(self, task_id):
         consumer = self._create_consumer(task_id, self.connection)