Re: [PATCH] wrapper: remove xunsetenv()

On Fri, Oct 29, 2021 at 05:37:16PM -0400, Jeff King wrote:

On Fri, Oct 29, 2021 at 02:27:05PM -0700, Carlo Marcelo Arenas Belón wrote:

quoted

Platforms that are using the git compatibility layer for unsetenv
use void as a return value for unsetenv(), so any function that checks
for a return value will fail to build.

Good catch.

quoted

Remove the unused wrapper function.

I don't mind removing this if nobody is using it, but doesn't your first
paragraph argue that our definition of gitunsetenv() is just wrong?
I.e., it should return an int, even if it is always "0"?

Or is it a portability question? I.e., are there platforms where
unsetenv() also returns void, in which case we must make sure nobody
ever looks at its return value (and xunsetenv() is therefore a wrong
direction)?

Looks like Junio just posted such a patch in the other thread.

However, according to the unsetenv() manpage:

  Prior to glibc 2.2.2, unsetenv() was prototyped as returning void;
  more recent glibc versions follow the POSIX.1-compliant prototype
  shown in the SYNOPSIS.

So it is POSIX to return an int, but that gives us at least one platform
where unsetenv() returns void (or used to). glibc 2.2.2 is 2001-era, so
that may be old enough that we don't care. But it makes me wonder if
other older or obscure platforms will run into this.

-Peff