raise(-1) has stopped returning an error recently

[Duncan Roe]

On Wed, Nov 24, 2021 at 10:25:46AM +0100, cygwin wrote: [...]
>
> What is that "permanent restriction" in Cygwin?  Is that something we
> could fix or something unfixable?  Did you try to debug Cygwin in terms
> of that problem?  If not, could you extract a reduced, very simple
> stand-alone testcase for further debugging?
>
The restriction is in grep/gnulib source. From
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27555#5

>> I've determined the cause, at least. The sole caller of mbstoupper
>> (which contained the relevant __CYGWIN__-specific
>> surrogate-pair-handling code) was removed by the improvements of
>> v2.21-63-g8a33cde, and not long after, I noticed that mbstoupper was
>> no longer used, so removed it altogether.

I submitted a patch to save anyone else wasting time over this. So please don't
you,

Cheers ... Duncan.