Need to do CommandCounterIncrement after StoreAttrMissingVal.
Without this, an additional change to the same pg_attribute row
within the same command will fail. This is possible at least with
ALTER TABLE ADD COLUMN on a multiple-inheritance-pathway structure.
(Another potential hazard is that immediately-following operations
might not see the missingval.)
Introduced by
95f650674, which split the former coding that
used a single pg_attribute update to change both atthasdef and
atthasmissing/attmissingval into two updates, but missed that
this should entail two CommandCounterIncrements as well. Like
that fix, back-patch through v13.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/
025a3ffa-5eff-4a88-97fb-
8f583b015965@gmail.com
Backpatch-through: 13