From d7576d223dc87155e2df29767444f7cf5fe6bbe4 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Wed, 3 Feb 2016 15:34:20 +0000
Subject: [PATCH] Don't try to use local echoes as scroll tokens

Local echoes don't have a (usable) event id, so don't use them when remembering
the scroll state of a room.
---
 src/components/structures/RoomView.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index c46149bfeb..09b6baf2be 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -995,8 +995,18 @@ module.exports = React.createClass({
 
             var eventId = mxEv.getId();
             var highlight = (eventId == this.props.highlightedEventId);
+
+            var scrollToken = eventId;
+            // we can't use local echoes as scroll tokens, because their event
+            // IDs change.
+            if (mxEv.status) {
+                scrollToken = undefined;
+            }
+
             ret.push(
-                <li key={eventId} ref={this._collectEventNode.bind(this, eventId)} data-scroll-token={eventId}>
+                <li key={eventId} 
+                        ref={this._collectEventNode.bind(this, eventId)} 
+                        data-scroll-token={scrollToken}>
                     <EventTile mxEvent={mxEv} continuation={continuation}
                         last={last} isSelectedEvent={highlight}/>
                 </li>