diff options
| -rw-r--r-- | changelog.d/10690.bugfix | 1 | ||||
| -rw-r--r-- | synapse/storage/databases/main/purge_events.py | 22 |
2 files changed, 14 insertions, 9 deletions
diff --git a/changelog.d/10690.bugfix b/changelog.d/10690.bugfix new file mode 100644 index 0000000000..059eea7464 --- /dev/null +++ b/changelog.d/10690.bugfix @@ -0,0 +1 @@ +Fix a long-standing bug that caused an `AssertionError` when purging history in certain rooms. Contributed by @Kokokokoka. diff --git a/synapse/storage/databases/main/purge_events.py b/synapse/storage/databases/main/purge_events.py index bccff5e5b9..3eb30944bf 100644 --- a/synapse/storage/databases/main/purge_events.py +++ b/synapse/storage/databases/main/purge_events.py @@ -102,15 +102,19 @@ class PurgeEventsStore(StateGroupWorkerStore, CacheInvalidationWorkerStore): (room_id,), ) rows = txn.fetchall() - max_depth = max(row[1] for row in rows) - - if max_depth < token.topological: - # We need to ensure we don't delete all the events from the database - # otherwise we wouldn't be able to send any events (due to not - # having any backwards extremities) - raise SynapseError( - 400, "topological_ordering is greater than forward extremeties" - ) + # if we already have no forwards extremities (for example because they were + # cleared out by the `delete_old_current_state_events` background database + # update), then we may as well carry on. + if rows: + max_depth = max(row[1] for row in rows) + + if max_depth < token.topological: + # We need to ensure we don't delete all the events from the database + # otherwise we wouldn't be able to send any events (due to not + # having any backwards extremities) + raise SynapseError( + 400, "topological_ordering is greater than forward extremities" + ) logger.info("[purge] looking for events to delete") |