[PATCH] Fix issue with successful malloc setting ENOMEM errno

[DJ Delorie]

Zack Weinberg via Libc-alpha <libc-alpha@sourceware.org> writes:
> On Thu, Sep 23, 2021, at 6:11 PM, Florian Weimer via Libc-alpha wrote:
>> We cannot set errno to zero, POSIX does not allow this.
>
> I believe this is an ISO C requirement, not only POSIX.

We do, however, allow for a save/restore around internal code where we
don't want those errors to affect a returned error status.