Repair find_inheritance_children with no active snapshot
When working on a scan with only a catalog snapshot, we may not have an
ActiveSnapshot set.  If we were to come across a detached partition,
that would cause a crash.  Fix by only ignoring detached partitions when
there's an active snapshot.
@@ -106,10 +106,13 @@ find_inheritance_children(Oid parentrelId, bool include_detached,
*
* The reason for this check is that we want to avoid seeing the
* partition as alive in RI queries during REPEATABLE READ or
- * SERIALIZABLE transactions.
+ * SERIALIZABLE transactions. (If there's no active snapshot set,
+ * that means we're not running a user query, so it's OK to always
+ * include detached partitions in that case.)
*/
if (((Form_pg_inherits) GETSTRUCT(inheritsTuple))->inhdetachpending &&
- !include_detached)
+ !include_detached &&
+ ActiveSnapshotSet())
{
TransactionId xmin;
Snapshot snap;
