Set depth_delta to undefined if something goes wrong. Or indeed if something goes right, but in that case we are about to overwrite it.

1 files changed, 3 insertions, 4 deletions

diff --git a/src/rabbit_mirror_queue_slave.erl b/src/rabbit_mirror_queue_slave.erl
index 1658b2ad3f..b12f85b89a 100644
--- a/src/rabbit_mirror_queue_slave.erl
+++ b/src/rabbit_mirror_queue_slave.erl
@@ -227,11 +227,10 @@ handle_cast({sync_start, Ref, Syncer},
                              backing_queue       = BQ,
                              backing_queue_state = BQS }) ->
     State1 = #state{rate_timer_ref = TRef} = ensure_rate_timer(State),
-    S = fun({TRefN, BQSN}) -> State1#state{rate_timer_ref      = TRefN,
+    S = fun({TRefN, BQSN}) -> State1#state{depth_delta         = undefined,
+                                           rate_timer_ref      = TRefN,
                                            backing_queue_state = BQSN} end,
     %% [0] We can only sync when there are no pending acks
-    %% [1] The master died so we do not need to set_delta even though
-    %%     we purged since we will get a depth instruction soon.
     case rabbit_mirror_queue_sync:slave(
            DD, Ref, TRef, Syncer, BQ, BQS,
            fun (BQN, BQSN) ->
@@ -241,7 +240,7 @@ handle_cast({sync_start, Ref, Syncer},
                    {TRefN, BQSN1}
            end) of
         {ok,           Res} -> noreply(set_delta(0, S(Res))); %% [0]
-        {failed,       Res} -> noreply(S(Res));               %% [1]
+        {failed,       Res} -> noreply(S(Res));
         {stop, Reason, Res} -> {stop, Reason, S(Res)}
     end;