Fix Mattermost event deduplication

Mattermost assigns its own IDs to messages, thus when sending a message
to Mattermost the event_seen key that has to be written must take into
account that ID and not the one that we put in the event (which was the
Matrix event ID)

Note that for XMPP anything can be used as an ID, so using the Matrix
event ID there worked, but it's actually not so good.

1 files changed, 9 insertions, 3 deletions

diff --git a/db.go b/db.go
index f9bed06..cdbdca1 100644
--- a/db.go
+++ b/db.go
@@ -163,6 +163,14 @@ func dbKvPut(key string, value string) {
 	dbLockSlot(slot_key)
 	defer dbUnlockSlot(slot_key)
 
+	dbKvPutLocked(key, value)
+}
+
+// Variant of dbKvPut that does not take a lock,
+// use this if the slot is already locked
+func dbKvPutLocked(key string, value string) {
+	slot_key := dbKvSlotKey(key)
+
 	var entry DbKv
 	db.Where(&DbKv{Key: key}).Assign(&DbKv{Value: value}).FirstOrCreate(&entry)
 	dbCache.Add(slot_key, value)
@@ -179,9 +187,7 @@ func dbKvTestAndSet(key string, value string) bool {
 		return false
 	}
 
-	var entry DbKv
-	db.Where(&DbKv{Key: key}).Assign(&DbKv{Value: value}).FirstOrCreate(&entry)
-	dbCache.Add(slot_key, value)
+	dbKvPutLocked(key, value)
 	return true
 }