Fix buggy interaction between array subscripts and subplan params In a7f107df2 I changed subplan param evaluation to happen within the containing expression. As part of that, ExecInitSubPlanExpr() was changed to evaluate parameters via a new EEOP_PARAM_SET expression step. These parameters were temporarily stored into ExprState->resvalue/resnull, with some reasoning why that would be fine. Unfortunately, that analysis was wrong - ExecInitSubscriptionRef() evaluates the input array into "resv"/"resnull", which will often point to ExprState->resvalue/resnull. This means that the EEOP_PARAM_SET, if inside an array subscript, would overwrite the input array to array subscript.
The fix is fairly simple - instead of evaluating into ExprState->resvalue/resnull, store the temporary result of the subplan in the subplan's return value. Bug: #19370 Reported-by: Zepeng Zhang <[email protected]> Diagnosed-by: Tom Lane <[email protected]> Diagnosed-by: Andres Freund <[email protected]> Discussion: https://postgr.es/m/[email protected] Backpatch-through: 18 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/bdc5dedfcaa57ddeef115252283019d79083d8a2 Modified Files -------------- src/backend/executor/execExpr.c | 18 ++++++++++-------- src/backend/executor/execExprInterp.c | 6 +++--- src/test/regress/expected/subselect.out | 17 +++++++++++++++++ src/test/regress/sql/subselect.sql | 11 +++++++++++ 4 files changed, 41 insertions(+), 11 deletions(-)
