[MM-60307] Check if session is nil before calling UpdateLastActivityAtIfNeeded (#28254)

server/channels/app/platform/session.go

@@ -17,11 +17,12 @@ import (
 func (ps *PlatformService) ReturnSessionToPool(session *model.Session) {
 	if session != nil {
 		session.Id = ""
-		// Once the session is retrieved from the pool, all existing prop fields are cleared.
-		// To avoid a race between clearing the props and accessing it, clear the props maps before returning it to the pool.
+		// All existing prop fields are cleared once the session is retrieved from the pool.
+		// To speed up that process, clear the props here to avoid doing that in the hot path.
+		//
+		// If the request handler spawns a goroutine that uses the session, it might race with this code.
+		// In that case, the handler should copy the session and use the copy in the goroutine.
 		clear(session.Props)
-		// Also clear the team members slice to avoid a similar race condition.
-		clear(session.TeamMembers)
 		ps.sessionPool.Put(session)
 	}
 }

server/channels/app/platform/web_conn.go

@@ -253,7 +253,10 @@ func (ps *PlatformService) NewWebConn(cfg *WebConnConfig, suite SuiteIFace, runn
 		// Create a goroutine to avoid blocking the creation of the websocket connection.
 		ps.Go(func() {
 			ps.SetStatusOnline(userID, false)
-			ps.UpdateLastActivityAtIfNeeded(*wc.GetSession())
+			session := wc.GetSession()
+			if session != nil {
+				ps.UpdateLastActivityAtIfNeeded(*session)
+			}
 		})
 	}