Comment 130 for bug 727064

> If you prefer, the POSIX man page for memcpy states: "If copying takes
> place between objects that overlap, the behavior is undefined."

Yes, for POSIX compliance, it is necessary to assume that the behaviour is
undefined. I doubt, though, that Adobe is claiming POSIX conformance or
portability for its code.

I don't think we are talking about whether glibc/linux *may* change the
implementation while still staying POSIX compliant. We should be talking about
whether glibc/linux *should* change the current behaviour while programs exist
which don't follow the fine (but soft) advice of current documentation, and
will fail if that behaviour changes. That's an issue worthy of discussion,
which can't be decided by references to BSD documentation and POSIX standards.