Re: DETOASTing in custom memory context

strk <strk@keybit.net> writes:
>> From whitin an aggregate sfunc I did:
>         oldcontext = MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
>         geom = (GEOMETRY *)PG_DETOAST_DATUM(datum);
>         MemoryContextSwitchTo(oldcontext);

> And later in aggregate's finalfunc:
>     pfree(geom);

> Result:
>     segfault!

> What's wrong with it ?

Perhaps you wanted PG_DETOAST_DATUM_COPY().  Or possibly use
PG_FREE_IF_COPY() rather than an unconditional pfree, though
that would depend on just what your usage pattern is.
        regards, tom lane