Merge pull request #5418 from matrix-org/erikj/fix_send_fed_with_limi…

…t_zero Fix bug sending federation transactions with lots of EDUs
matrix-org · Jun 10, 2019 · 78e74ab · 78e74ab
2 parents 0167447 + 48748c0
commit 78e74ab
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diff --git a/changelog.d/5418.bugfix b/changelog.d/5418.bugfix
@@ -0,0 +1 @@
+Fix bug where attempting to send transactions with large number of EDUs can fail.
diff --git a/synapse/storage/deviceinbox.py b/synapse/storage/deviceinbox.py
@@ -138,6 +138,10 @@ def get_new_device_msgs_for_remote(
         if not has_changed or last_stream_id == current_stream_id:
             return defer.succeed(([], current_stream_id))
 
+        if limit <= 0:
+            # This can happen if we run out of room for EDUs in the transaction.
+            return defer.succeed(([], last_stream_id))
+
         def get_new_messages_for_remote_destination_txn(txn):
             sql = (
                 "SELECT stream_id, messages_json FROM device_federation_outbox"