From c0577ea87a19c169d68ed83760582fa1fabe36e5 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 8 Sep 2014 18:34:18 +0100
Subject: [PATCH] Rollback if we try and insert duplicate events

---
 synapse/storage/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 81c3c94b2e..8ed80109a5 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -179,6 +179,7 @@ class DataStore(RoomMemberStore, RoomStore,
                 "Failed to persist, probably duplicate: %s",
                 event.event_id
             )
+            txn.rollback()
             return
 
         if not backfilled and hasattr(event, "state_key"):