| From: | Michael van Elst <mlelstv(at)serpens(dot)de> |
|---|---|
| To: | Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Neil Conway <neilc(at)samurai(dot)com>, PostgreSQL Patches <pgsql-patches(at)postgresql(dot)org> |
| Subject: | Re: fix memcpy() overlap |
| Date: | 2004-02-02 22:19:49 |
| Message-ID: | 20040202221949.GA24798@serpens.de |
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| Thread: | |
| Lists: | pgsql-patches |
On Mon, Feb 02, 2004 at 01:23:15PM -0800, Stephan Szabo wrote:
>
> Isn't memcpy on overlapping (even entirely overlapping) buffers undefined
> behavior unless the count is 0?
The C standard says: "If copying takes place between objects that overlap,
the behaviour is undefined". SUSv3 says the same.
To my understanding this also includes copying something onto itself.
--
Michael van Elst
Internet: mlelstv(at)serpens(dot)de
"A potential Snark may lurk in every tree."
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