From c5f2da587532c80cda066acc715344b74a9d19d5 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Fri, 15 Aug 2014 11:47:01 +0100
Subject: Add a check to make sure that during state conflict res we only
 request a PDU we don't have.

---
 synapse/state.py    | 12 ++++++++++--
 tests/test_state.py |  3 +++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/synapse/state.py b/synapse/state.py
index d8977b61ea..4f8b4d9760 100644
--- a/synapse/state.py
+++ b/synapse/state.py
@@ -191,10 +191,18 @@ class StateHandler(object):
                 key=lambda x: x.depth
             )
 
+            pdu_id = missing_prev.prev_state_id
+            origin = missing_prev.prev_state_origin
+
+            is_missing = yield self.store.get_pdu(pdu_id, origin) is None
+
+            if not is_missing:
+                raise Exception("Conflict resolution failed.")
+
             yield self._replication.get_pdu(
                 destination=missing_prev.origin,
-                pdu_origin=missing_prev.prev_state_origin,
-                pdu_id=missing_prev.prev_state_id,
+                pdu_origin=origin,
+                pdu_id=pdu_id,
                 outlier=True
             )
 
diff --git a/tests/test_state.py b/tests/test_state.py
index a2908a2eac..aaf873a856 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -37,6 +37,7 @@ class StateTestCase(unittest.TestCase):
             "update_current_state",
             "get_latest_pdus_in_context",
             "get_current_state",
+            "get_pdu",
         ])
         self.replication = Mock(spec=["get_pdu"])
 
@@ -220,6 +221,8 @@ class StateTestCase(unittest.TestCase):
 
         self.replication.get_pdu.side_effect = set_return_tree
 
+        self.persistence.get_pdu.return_value = None
+
         is_new = yield self.state.handle_new_state(new_pdu)
 
         self.assertTrue(is_new)
-- 
cgit 1.4.1