Re: [PATCH v4] grep: fix multibyte regex handling under macOS

[Diomidis Spinellis <dds@aueb.gr>]

On 13-Sep-22 20:32, Junio C Hamano wrote:
>> +#include <locale.h>
>>   #ifdef NEEDS_SYS_PARAM_H
>>   #include <sys/param.h>
>>   #endif
> 
> I'll let others more familiar with the locale support to comment on
> these changes.  We are unconditionally including <locale.h> now;
> platforms that lack <locale.h> could set NO_GETTEXT to work it
> around before this change, but that will no longer work.
> 
> I do not know if thta is a practical downside to anybody, but it
> could be a problem.
> 
> Perhaps cook this in 'next' and see if anybody screams?

I was programming in C before locale.h was introduced, so its 
availability was something that worried me as well.  I looked up whether 
we could/should use a GNU autoconf macro to test for the locale.h 
availability.  According to autoconf's documentation "All hosted 
environments that are still of interest for portable code provide all of 
the headers specified in ISO C90 (as amended in 1995): assert.h, [...] 
locale.h [...], and wctype.h. Most programs can safely include these 
headers unconditionally." [1]

[1] https://www.gnu.org/software/autoconf/manual/autoconf-2.70/autoconf.html