Fix self-join removal to update bare Var references in join clauses Self-join removal failed to update Var nodes when the join clause was a bare Var (e.g., ON t1.bool_col) rather than an expression containing Vars. ChangeVarNodesWalkExpression() used expression_tree_walker(), which descends into child nodes but does not process the top-level node itself. When a bare Var referencing the removed relation appeared as the clause, its varno was left unchanged, leading to "no relation entry for relid N" errors.
Fix by calling ChangeVarNodes_walker() directly instead of expression_tree_walker(), so the top-level node is also processed. Bug: #19435 Reported-by: Hang Ammmkilo <[email protected]> Author: Andrei Lepikhov <[email protected]> Co-authored-by: Tender Wang <[email protected]> Co-authored-by: Alexander Korotkov <[email protected]> Reviewed-by: Kirill Reshke <[email protected]> Discussion: https://www.postgresql.org/message-id/flat/19435-3cc1a87f291129f1%40postgresql.org Backpatch-through: 18 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/e8b9d6497469dadb3c2f3765dfeed7432af77704 Modified Files -------------- src/backend/rewrite/rewriteManip.c | 4 +--- src/test/regress/expected/join.out | 16 ++++++++++++++++ src/test/regress/sql/join.sql | 6 ++++++ 3 files changed, 23 insertions(+), 3 deletions(-)
