Re: gs_group_1 crashing on 13beta2/s390x

Andrew Gierth <andrew@tao11.riddles.org.uk> writes:
> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:
>  Tom> It's hardly surprising that datumCopy would segfault when given a
>  Tom> null "value" and told it is pass-by-reference. However, to get to
>  Tom> the datumCopy call, we must have passed the MemoryContextContains
>  Tom> check on that very same pointer value, and that would surely have
>  Tom> segfaulted as well, one would think.

> Nope, because MemoryContextContains just returns "false" if passed a
> NULL pointer.

Ah, right.  So you could imagine getting here if the finalfn had returned
PointerGetDatum(NULL) with isnull = false.  We have some aggregate
transfns that are capable of doing that for internal-type transvalues,
I think, but the finalfn never should do it.

In any case we still have the fact that this isn't being seen in our
buildfarm; and that's not for lack of s390 machines.  So I still think
the most likely explanation is a compiler bug in bleeding-edge gcc.

Probably what Christoph should be trying to figure out is why he can't
reproduce it manually.  There must be some discrepancy between his
environment and the build machines; but what?

            regards, tom lane