bug#43725: 28.0.50; Include feature/native-comp into master

[Andrea Corallo]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Andrea Corallo <akrl@sdf.org>
>> Cc: larsi@gnus.org, monnier@iro.umontreal.ca, 43725@debbugs.gnu.org
>> Date: Sun, 14 Mar 2021 19:06:01 +0000
>> 
>> Probably in this case I thought that because I've used
>> Ffile_name_as_directory its output could just be concatenated without
>> having to use Fexpand_file_name.
>> 
>> Is this practice incorrect or dangerous?
>
> It's "not recommended".  The reason is that expand-file-name deals
> with irregularities such as multiple consecutive slashes, unibyte vs
> multibyte strings, drive letters on MS-Windows, etc., and 'concat'
> doesn't.

I probably thought there was safe by construction but I see your point.

> I will go over the code and replace 'concat' where needed.

Thanks (again)

  Andrea