Thread: [COMMITTERS] pgsql: Fix incorrect handling of CTEs and ENRs as DML targetrelations.
[COMMITTERS] pgsql: Fix incorrect handling of CTEs and ENRs as DML targetrelations.
From
Tom Lane
Date:
Fix incorrect handling of CTEs and ENRs as DML target relations. setTargetTable threw an error if the proposed target RangeVar's relname matched any visible CTE or ENR. This breaks backwards compatibility in the CTE case, since pre-v10 we never looked for a CTE here at all, so that CTE names did not mask regular tables. It does seem like a good idea to throw an error for the ENR case, though, thus causing ENRs to mask tables for this purpose; ENRs are new in v10 so we're not breaking existing code, and we may someday want to allow them to be the targets of DML. To fix that, replace use of getRTEForSpecialRelationTypes, which was overkill anyway, with use of scanNameSpaceForENR. A second problem was that the check neglected to verify null schemaname, so that a CTE or ENR could incorrectly be thought to match a qualified RangeVar. That happened because getRTEForSpecialRelationTypes relied on its caller to have checked for null schemaname. Even though the one remaining caller got it right, this is obviously bug-prone, so move the check inside getRTEForSpecialRelationTypes. Also, revert commit 18ce3a4ab's extremely poorly thought out decision to add a NULL return case to parserOpenTable --- without either documenting that or adjusting any of the callers to check for it. The current bug seems to have arisen in part due to working around that bad idea. In passing, remove the one-line shim functions transformCTEReference and transformENRReference --- they don't seem to be adding any clarity or functionality. Per report from Hugo Mercier (via Julien Rouhaud). Back-patch to v10 where the bug was introduced. Thomas Munro, with minor editing by me Discussion: https://postgr.es/m/CAOBaU_YdPVH+PTtiKSSLOiiW3mVDYsnNUekK+XPbHXiP=wrFLA@mail.gmail.com Branch ------ REL_10_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/799037099b4f0a227bed40eee53bf4e995eb5390 Modified Files -------------- src/backend/parser/parse_clause.c | 74 +++++++++++++---------------------- src/backend/parser/parse_relation.c | 8 +--- src/test/regress/expected/plpgsql.out | 8 ++-- src/test/regress/expected/with.out | 18 ++++++++- src/test/regress/sql/plpgsql.sql | 4 +- src/test/regress/sql/with.sql | 10 ++++- 6 files changed, 59 insertions(+), 63 deletions(-) -- Sent via pgsql-committers mailing list (pgsql-committers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers