From 8b501f5fe674e8db217c7f72c374ca60494658bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Chmielowski?= <pchmielowski@process-one.net>
Date: Wed, 24 Apr 2019 13:46:09 +0200
Subject: [PATCH] Catch potential exceptions in gen_mod:wait_for_process

Seems that at ejabberd shutdown, process may terminate before that function
is called, and in that case erlang:monitor throws exception.
---
 src/gen_mod.erl | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/gen_mod.erl b/src/gen_mod.erl
index cec3ddb24..4dc972fd9 100644
--- a/src/gen_mod.erl
+++ b/src/gen_mod.erl
@@ -364,8 +364,13 @@ stop_module_keep_config(Host, Module) ->
     end.
 
 wait_for_process(Process) ->
-    MonitorReference = erlang:monitor(process, Process),
-    wait_for_stop(Process, MonitorReference).
+    try erlang:monitor(process, Process) of
+	MonitorReference ->
+	    wait_for_stop(Process, MonitorReference)
+    catch
+	_:_ ->
+	    ok
+    end.
 
 wait_for_stop(Process, MonitorReference) ->
     receive