Treat JsonConstructorExpr as non-strict

JsonConstructorExpr can produce non-NULL output with a NULL input, so
it should be treated as a non-strict construct.  Failing to do so can
lead to incorrect query behavior.

For example, in the reported case, when pulling up a subquery that is
under an outer join, if the subquery's target list contains a
JsonConstructorExpr that uses subquery variables and it is mistakenly
treated as strict, it will be pulled up without being wrapped in a
PlaceHolderVar.  As a result, the expression will be evaluated at the
wrong place and will not be forced to null when the outer join should
do so.

Back-patch to v16 where JsonConstructorExpr was introduced.

Bug: #19046
Reported-by: Runyuan He <[email protected]>
Author: Tender Wang <[email protected]>
Co-authored-by: Richard Guo <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 16

0 files changed, 0 insertions, 0 deletions