fix: Prevent redis task loss when closing connection while in poll (#1733)

* Catch brpop before closing connection

* Update unit test

---------

Co-authored-by: mbierma <3448579-mbierma@users.noreply.gitlab.com>

kombu/transport/redis.py

@@ -1079,6 +1079,11 @@ class Channel(virtual.Channel):
 
     def close(self):
         self._closing = True
+        if self._in_poll:
+            try:
+                self._brpop_read()
+            except Empty:
+                pass
         if not self.closed:
             # remove from channel poller.
             self.connection.cycle.discard(self)

t/unit/transport/test_redis.py

@@ -1290,6 +1290,15 @@ class test_Redis:
         assert conn1.disconnected
         assert conn2.disconnected
 
+    def test_close_in_poll(self):
+        c = Connection(transport=Transport).channel()
+        conn1 = c.client.connection
+        conn1._sock.data = [('BRPOP', ('test_Redis',))]
+        c._in_poll = True
+        c.close()
+        assert conn1.disconnected
+        assert conn1._sock.data == []
+
     def test_get__Empty(self):
         channel = self.connection.channel()
         with pytest.raises(Empty):