tags 824429 upstream
forwarded 824429 https://sourceware.org/bugzilla/show_bug.cgi?id=20617
* Christoph Biedl:
> It might be questionable whether this is a bug in glibc at all. But at
> least it's surprising behaviour.
> The reproducer below calls mbstowcs two times, first time with
> an illegal UTF-8 sequence, second time a correct one.
> Now if the caller's environment is set to something UTF-8-ish like
> "en_US.UTF-8" or "de_DE.UTF-8", also the second and any further
> mbsrtowcs invocation fail with EILSEQ. Note setting LC_CTYPE to an
> empty string is also required to make this happen.
POSIX and C11 explicitly say that the conversion state is undefined
after EILSEQ. There does not appear to be a way to reset the internal
(global) conversion state used by mbsrtowcs, so a NULL argument for
the conversion state pointer is rarely useful. We should probably add
a warning in glibc for that case.
Filed upstream: https://sourceware.org/bugzilla/show_bug.cgi?id=20617