From 9520c718cc925967d9048dcd4e70c404492b12f1 Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Wed, 5 Apr 2017 09:36:44 +0100
Subject: [PATCH] Review comments

---
 .../dendrite/clientapi/storage/current_room_state_table.go  | 2 ++
 .../dendrite/clientapi/storage/output_room_events_table.go  | 2 ++
 .../matrix-org/dendrite/clientapi/storage/syncserver.go     | 6 ++++++
 3 files changed, 10 insertions(+)

diff --git a/src/github.com/matrix-org/dendrite/clientapi/storage/current_room_state_table.go b/src/github.com/matrix-org/dendrite/clientapi/storage/current_room_state_table.go
index 229306ab4..bff60972f 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/storage/current_room_state_table.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/storage/current_room_state_table.go
@@ -27,6 +27,8 @@ CREATE TABLE IF NOT EXISTS current_room_state (
     -- Clobber based on 3-uple of room_id, type and state_key
     CONSTRAINT room_state_unique UNIQUE (room_id, type, state_key)
 );
+-- for event deletion
+CREATE UNIQUE INDEX IF NOT EXISTS event_id_idx ON current_room_state(event_id);
 `
 
 const upsertRoomStateSQL = "" +
diff --git a/src/github.com/matrix-org/dendrite/clientapi/storage/output_room_events_table.go b/src/github.com/matrix-org/dendrite/clientapi/storage/output_room_events_table.go
index 26cf1cdb8..a31759c3a 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/storage/output_room_events_table.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/storage/output_room_events_table.go
@@ -26,6 +26,8 @@ CREATE TABLE IF NOT EXISTS output_room_events (
     add_state_ids TEXT[],
     remove_state_ids TEXT[]
 );
+-- for event selection
+CREATE UNIQUE INDEX IF NOT EXISTS event_id_idx ON output_room_events(event_id);
 `
 
 const insertEventSQL = "" +
diff --git a/src/github.com/matrix-org/dendrite/clientapi/storage/syncserver.go b/src/github.com/matrix-org/dendrite/clientapi/storage/syncserver.go
index 6a85f703a..39df640b1 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/storage/syncserver.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/storage/syncserver.go
@@ -45,6 +45,12 @@ func (d *SyncServerDatabase) WriteEvent(ev *gomatrixserverlib.Event, addStateEve
 		if err := d.events.InsertEvent(txn, ev, addStateEventIDs, removeStateEventIDs); err != nil {
 			return err
 		}
+
+		if len(addStateEventIDs) == 0 && len(removeStateEventIDs) == 0 {
+			// Nothing to do, the event may have just been a message event.
+			return nil
+		}
+
 		// Update the current room state based on the added/removed state event IDs.
 		// In the common case there is a single added event ID which is the state event itself, assuming `ev` is a state event.
 		// However, conflict resolution may result in there being different events being added, or even some removed.