From d0560f594dfb17fb646cb1c1bc030fbf356db214 Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Wed, 16 Mar 2016 17:18:33 +0000
Subject: [PATCH] Set the right .sender value for m.room.member events

---
 lib/models/event-timeline.js                   | 7 ++++++-
 spec/integ/matrix-client-room-timeline.spec.js | 4 ++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/models/event-timeline.js b/lib/models/event-timeline.js
index cb2cc60b5..673e32e92 100644
--- a/lib/models/event-timeline.js
+++ b/lib/models/event-timeline.js
@@ -227,7 +227,12 @@ EventTimeline.prototype.addEvent = function(event, atStart, spliceBeforeLocalEch
         // it again if the prop wasn't previously set. It may also mean that
         // the sender/target is updated (if the event set was a room member event)
         // so we want to use the *updated* member (new avatar/name) instead.
-        if (!event.sender || event.getType() === "m.room.member") {
+        //
+        // However, we do NOT want to do this on member events if we're going
+        // back in time, else we'll set the .sender value for BEFORE the given
+        // member event, whereas we want to set the .sender value for the ACTUAL
+        // member event itself.
+        if (!event.sender || (event.getType() === "m.room.member" && !atStart)) {
             setEventMetadata(event, stateContext, atStart);
         }
     }
diff --git a/spec/integ/matrix-client-room-timeline.spec.js b/spec/integ/matrix-client-room-timeline.spec.js
index 062437578..8d5125f0c 100644
--- a/spec/integ/matrix-client-room-timeline.spec.js
+++ b/spec/integ/matrix-client-room-timeline.spec.js
@@ -288,7 +288,7 @@ describe("MatrixClient room timelines", function() {
                 oldMshipEvent,
                 utils.mkMessage({
                     user: userId, room: roomId, msg: "I'm old alice"
-                }),                
+                }),
                 joinMshipEvent,
             ];
 
@@ -300,7 +300,7 @@ describe("MatrixClient room timelines", function() {
 
                 client.scrollback(room).done(function() {
                     expect(room.timeline.length).toEqual(5);
-                    var joinMsg = room.timeline[0]; 
+                    var joinMsg = room.timeline[0];
                     expect(joinMsg.sender.name).toEqual("Old Alice");
                     var oldMsg = room.timeline[1];
                     expect(oldMsg.sender.name).toEqual("Old Alice");