From fdbc1191b272e631a9d6fd99c445d3238266a247 Mon Sep 17 00:00:00 2001
From: Patrick Connolly <patrick.c.connolly@gmail.com>
Date: Thu, 29 Nov 2018 01:57:27 +0800
Subject: [PATCH] Preserve ThreadTimestamp from SubMessage for edits.

Since we're using ThreadTimestamp and ParentID to know if original message is threaded, we need to extract it from SubMessage for edits.
---
 bridge/slack/helpers.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/bridge/slack/helpers.go b/bridge/slack/helpers.go
index b0af50f5..e4b2e810 100644
--- a/bridge/slack/helpers.go
+++ b/bridge/slack/helpers.go
@@ -189,6 +189,13 @@ func (b *Bslack) populateReceivedMessage(ev *slack.MessageEvent) (*config.Messag
 		}
 	}
 
+	// For edits, only submessage has thread ts.
+	// Ensures edits to threaded messages maintain their prefix hint on the
+	// unthreaded end.
+	if ev.SubMessage != nil {
+		rmsg.ParentID = ev.SubMessage.ThreadTimestamp
+	}
+
 	if err = b.populateMessageWithUserInfo(ev, rmsg); err != nil {
 		return nil, err
 	}