From 440f9d129b5a728a0ef6a900f5cc273782f04eec Mon Sep 17 00:00:00 2001
From: Zaiming Shi <zaiming.shi@tink.se>
Date: Thu, 28 Nov 2019 14:46:46 +0100
Subject: [PATCH] Handle undefined fetcher in fold loop exception

Prior to this commit, fold loop may crash if there
is an exception in message handler callback when
processing the last batch (i.e. when there is no
running fetcher for the next batch), kill_fetcher
function may crash on 'undefined' clause
---
 src/brod_utils.erl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/brod_utils.erl b/src/brod_utils.erl
index e9b3f83d..78508f83 100644
--- a/src/brod_utils.erl
+++ b/src/brod_utils.erl
@@ -612,6 +612,7 @@ do_acc(Spawn, Fetcher, Offset, Acc, Fun, [Msg | Rest], End, Count) ->
       erlang:raise(C, E, Stack)
   end.
 
+kill_fetcher(undefined) -> ok;
 kill_fetcher({Pid, Mref}) ->
   exit(Pid, kill),
   receive