On Sun, May 18, 2025 at 7:31 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > While chasing down Valgrind leakage reports, I was disturbed > to realize that some of them arise from a case where the > executor scribbles on the plan tree it's given, which it is > absolutely not supposed to do: > > /* > * Initialize result tuple slot and assign its rowtype using the first > * RETURNING list. We assume the rest will look the same. > */ > mtstate->ps.plan->targetlist = (List *) linitial(returningLists); > > A bit of git archaeology fingers Andres' commit 4717fdb14, which we > can't easily revert since he later got rid of ExecAssignResultType > altogether. But I think we need to do something about it --- it's > purest luck that this doesn't cause serious problems in some cases.
Is there some way that we can detect violations of this rule automatically? I recall that we were recently discussing with Richard Guo a proposed patch that would have had a similar problem, so it's evidently not that hard for a committer to either fail to understand what the rule is or fail to realize that they are violating it. -- Robert Haas EDB: http://www.enterprisedb.com
