Re: [PATCH 1/2] posix: Falling back to non wide mode in case of encoding error [BZ #14185]

[Florian Weimer]

* Adhemerval Zanella via Libc-alpha:

> +static int
> +fnmatch_convert_to_wide (const char *str, struct scratch_buffer *buf,
> +                         size_t *n)
> +{
> +  mbstate_t ps;
> +  memset (&ps, '\0', sizeof (ps));
> +
> +  size_t nw = buf->length / sizeof (wchar_t);
> +  *n = strnlen (str, nw - 1);
> +  if (__glibc_likely (*n < nw))
> +    {
> +      const char *p = str;
> +      *n = mbsrtowcs (buf->data, &p, *n + 1, &ps);
> +      if (__glibc_unlikely (*n == (size_t) -1))
> +        /* Something wrong.
> +           XXX Do we have to set 'errno' to something which mbsrtows hasn't
> +           already done?  */
> +        return -1;
> +      if (p == NULL)
> +        return 0;
> +      memset (&ps, '\0', sizeof (ps));
> +    }
> +
> +  *n = mbsrtowcs (NULL, &str, 0, &ps);
> +  if (__glibc_unlikely (*n == (size_t) -1))
> +    return -1;
> +  if (!scratch_buffer_set_array_size (buf, *n + 1, sizeof (wchar_t)))
> +    {
> +      __set_errno (ENOMEM);
> +      return -2;
> +    }
> +  assert (mbsinit (&ps));
> +  mbsrtowcs (buf->data, &str, *n + 1, &ps);
> +  return 0;
> +}
>

This, along with

> +      if (r == -2 || r == 0)
> +        return r;

below causes fnmatch to return the undocumented -2 error value, I think.
Shouldn't we keep failing with -1 on error?

Thanks,
Florian