Re: exec_execute_message crash

Tatsuo Ishii <ishii(at)postgresql(dot)org> writes:
> parse causes transaction to abort, which causes call to
> AbortCurrentTransaction->AbortTransaction->AtAbort_portals->ReleaseCachedPlan. It
> calls ReleaseCachePlan(portal->cplan). ReleaseCachePlan calls
> MemoryContextDelete(plan->context) which destroys both portal->cplan
> and portal->stmts.

> That was the reason why I had segfault by accessing portal->stmts.

> To fix this I think exec_execute_message should throw an error if
> portal->cleanup is NULL, since portal->cleanup is NULLed by
> AtAbort_Portals at transaction abort (or portal is dropped).

This is just a kluge, and a rather bad one I think. The real problem
here is that AtAbort_Portals destroys the portal contents and doesn't
do anything to record the fact. It should probably be putting the
portal into PORTAL_FAILED state, and what exec_execute_message ought
to be doing is checking for that. It might be a good idea to explicitly
zero out the now-dangling pointers in the Portal struct, too.

It'd be nice to have a test case for this, hint hint ...

regards, tom lane