From c98e1479bd39a64add0456299644e96480151625 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 7 Jul 2016 11:41:07 +0100
Subject: [PATCH] Return 400 rather than 500

---
 synapse/storage/events.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 23ebd5d4c..c2136f3fd 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -23,6 +23,7 @@ from synapse.util.async import ObservableDeferred
 from synapse.util.logcontext import preserve_fn, PreserveLoggingContext
 from synapse.util.logutils import log_function
 from synapse.api.constants import EventTypes
+from synapse.api.errors import SynapseError
 
 from canonicaljson import encode_canonical_json
 from collections import deque, namedtuple
@@ -1324,7 +1325,9 @@ class EventsStore(SQLBaseStore):
         max_depth = max(row[0] for row in rows)
 
         if max_depth <= topological_ordering:
-            raise Exception("topological_ordering is greater than forward extremeties")
+            raise SynapseError(
+                400, "topological_ordering is greater than forward extremeties"
+            )
 
         txn.execute(
             "SELECT event_id, state_key FROM events"