From e854300ee674596aa06afaf28c2d789bf3905fa7 Mon Sep 17 00:00:00 2001
From: Ryan ZHAO <ryanzhaors@qq.com>
Date: Tue, 4 Feb 2020 17:04:00 +1100
Subject: [PATCH] fix the bug when a group member quit the group and other
 members will see no members in the group

---
 SignalServiceKit/src/Messages/OWSMessageManager.m | 1 +
 1 file changed, 1 insertion(+)

diff --git a/SignalServiceKit/src/Messages/OWSMessageManager.m b/SignalServiceKit/src/Messages/OWSMessageManager.m
index 618672752..371672774 100644
--- a/SignalServiceKit/src/Messages/OWSMessageManager.m
+++ b/SignalServiceKit/src/Messages/OWSMessageManager.m
@@ -1464,6 +1464,7 @@ NS_ASSUME_NONNULL_BEGIN
                     OWSLogWarn(@"ignoring quit group message from unknown group.");
                     return nil;
                 }
+                newMemberIds = [NSMutableSet setWithArray:oldGroupThread.groupModel.groupMemberIds];
                 [newMemberIds removeObject:hexEncodedPublicKey];
                 oldGroupThread.groupModel.groupMemberIds = [newMemberIds.allObjects mutableCopy];
                 [oldGroupThread saveWithTransaction:transaction];