Consumer: __exit__ should not cancel if connection error (Closes #670)

kombu/messaging.py

@@ -430,11 +430,14 @@ class Consumer(object):
         self.consume()
         return self
 
-    def __exit__(self, *exc_info):
-        try:
-            self.cancel()
-        except Exception:
-            pass
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if self.channel:
+            conn_errors = self.channel.connection.client.connection_errors
+            if not isinstance(exc_val, conn_errors):
+                try:
+                    self.cancel()
+                except Exception:
+                    pass
 
     def add_queue(self, queue):
         """Add a queue to the list of queues to consume from.

t/unit/test_messaging.py

@@ -262,6 +262,15 @@ class test_Consumer:
             pass
         c.cancel.assert_called_with()
 
+    def test_enter_exit_cancel_not_called_on_connection_error(self):
+        c = Consumer(self.connection)
+        c.cancel = Mock(name='Consumer.cancel')
+        assert self.connection.connection_errors
+        with pytest.raises(self.connection.connection_errors[0]):
+            with c:
+                raise self.connection.connection_errors[0]()
+        c.cancel.assert_not_called()
+
     def test_receive_callback_accept(self):
         message = Mock(name='Message')
         message.errors = []