When log events are retrieved through the API, suppression events are filtered out, even for users in the oversight group. In particular, mywiki/api.php?action=query&list=logevents&letype=suppress always returns an empty list.
I think the issue comes from the following function call in includes/api/ApiQueryLogEvents.php, line 61:
$hideLogs = LogEventsList::getExcludeClause( $db );
Changing it to getExcludeClause( $db, 'user' ) should fix it.
Version: 1.21.x
Severity: normal