From 1a32439d7e8e2494cbc9f90a47e9c5d3e871574a Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Fri, 18 Aug 2023 02:00:43 +0530
Subject: [PATCH] Ensure older session does not clobeer newer session. (#1974)

---
 pkg/rtc/participant_signal.go | 3 +--
 pkg/rtc/room.go               | 9 +++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/pkg/rtc/participant_signal.go b/pkg/rtc/participant_signal.go
index a9ae4dfab..e634fa573 100644
--- a/pkg/rtc/participant_signal.go
+++ b/pkg/rtc/participant_signal.go
@@ -58,8 +58,7 @@ func (p *ParticipantImpl) SendJoinResponse(joinResponse *livekit.JoinResponse) e
 		return err
 	}
 
-	// update state after to sending message, so that no participant updates could slip through before JoinResponse is
-	// sent
+	// update state after sending message, so that no participant updates could slip through before JoinResponse is sent
 	p.updateLock.Lock()
 	if p.State() == livekit.ParticipantInfo_JOINING {
 		p.updateState(livekit.ParticipantInfo_JOINED)
diff --git a/pkg/rtc/room.go b/pkg/rtc/room.go
index 7d8a12a03..f614f8979 100644
--- a/pkg/rtc/room.go
+++ b/pkg/rtc/room.go
@@ -1069,6 +1069,15 @@ func (r *Room) pushAndDequeueUpdates(pi *livekit.ParticipantInfo, isImmediate bo
 				return nil
 			}
 		}
+	} else {
+		ep := r.GetParticipant(identity)
+		if ep != nil {
+			epi := ep.ToProto()
+			if epi.JoinedAt > pi.JoinedAt {
+				// older session update, newer session has already become active, so nothing to do
+				return nil
+			}
+		}
 	}
 
 	if shouldSend {