pgsql: Don't mess up pstate->p_next_resno in transformOnConflictClause( - Mailing list pgsql-committers

From Tom Lane
Subject pgsql: Don't mess up pstate->p_next_resno in transformOnConflictClause(
Date
Msg-id E1cDd06-0002k0-VG@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Don't mess up pstate->p_next_resno in transformOnConflictClause().

transformOnConflictClause incremented p_next_resno while generating the
phony targetlist for the EXCLUDED pseudo-rel.  Then that field got
incremented some more during transformTargetList, possibly leading to
free_parsestate concluding that we'd overrun the allowed length of a tlist,
as reported by Justin Pryzby.

We could fix this by resetting p_next_resno to 1 after using it for the
EXCLUDED pseudo-rel tlist, but it seems easier and less coupled to other
places if we just don't use that field at all in this loop.  (Note that
this doesn't change anything about the resnos that end up appearing in
the main target list, because those are all replaced with target-column
numbers by updateTargetListEntry.)

In passing, fix incorrect type OID assigned to the whole-row Var for
"EXCLUDED.*" (somehow this escaped having any bad consequences so far,
but it's certainly wrong); remove useless assignment to var->location;
pstrdup the column names in case of a relcache flush; and improve
nearby comments.

Back-patch to 9.5 where ON CONFLICT was introduced.

Report: https://postgr.es/m/20161204163237.GA8030@telsasoft.com

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/3850723208888a6fe90b75ebf692af79119f4158

Modified Files
--------------
src/backend/parser/analyze.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)


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