From 93765bd956bea26206043de8cbb0ae4b67e4df15 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 9 Oct 2019 22:00:50 -0700 Subject: Fix table rewrites that include a column without a default. In c2fe139c201c I made ATRewriteTable() use tuple slots. Unfortunately I did not notice that columns can be added in a rewrite that do not have a default, when another column is added/altered requiring one. Initialize columns to NULL again, and add tests. Bug: #16038 Reported-By: anonymous Author: Andres Freund Discussion: https://postgr.es/m/16038-5c974541f2bf6749@postgresql.org Backpatch: 12, where the bug was introduced in c2fe139c201c --- src/backend/commands/tablecmds.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'src/backend/commands/tablecmds.c') diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 05593f33162..ba8f4459f3d 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -4890,6 +4890,16 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode) table_slot_callbacks(oldrel)); newslot = MakeSingleTupleTableSlot(newTupDesc, table_slot_callbacks(newrel)); + + /* + * Set all columns in the new slot to NULL initially, to ensure + * columns added as part of the rewrite are initialized to + * NULL. That is necessary as tab->newvals will not contain an + * expression for columns with a NULL default, e.g. when adding a + * column without a default together with a column with a default + * requiring an actual rewrite. + */ + ExecStoreAllNullTuple(newslot); } else { -- cgit v1.2.3