Re: [HACKERS] Backend terminated abnormally

I wrote:
> Actually, the missing clue seems to be that it's cool on HPUX and
> coredumps on Linux.  Bigendian vs. littleendian bug maybe?  I'm on
> it...

Well, isn't *this* special: it seems that memmove(dest, NULL, n)
doesn't cause a coredump on HPUX, it just silently does nothing.
Sheesh.  I hardly ever use memmove, or I would've found this out
before (and complained about it!).


Anyway, the answer to the original complaint is that geo_ops.c
is brimful of operators that think they can return a NULL pointer
and it'll be interpreted as returning an SQL NULL.  They are
sadly misinformed.  In the present state of fmgr() there isn't
any way for a binary operator to return NULL when its operands
are not null.  Another reason we gotta redo the fmgr interface.

Nick, I'm afraid '#' is pretty seriously broken: it'll coredump
whenever presented non-intersecting segments, unless you are able
to recompile the system so that dereferencing a NULL pointer is
not a fatal error.  Several of the other geometric operators have
similar problems.  AFAICS there is not much that can be done to
patch around this; a proper fix will require some major changes
that we are planning for release 7.0.  Sorry the news isn't better.
        regards, tom lane