Use return value of getpwuid_r(), not errno

[arnaud-lb]

getpwuid_r() and other reentrant functions used in ext/posix return an error number and may not set errno. #13921 updated ext/posix to use the return value, but one change was forgotten.

#13921 also sets the buffer len to 1 by default in debug builds, which allowed to detect this issue on Mac OS.

[nielsdos]

Indeed! nice one.
I checked other reentrant ones in this file but this seems to be the only mistake indeed.

[dstogov]

Please target this to PHP-8.2

[arnaud-lb]

@dstogov indeed, I forgot to change the target!

[iluuu1994]

@arnaud-lb It seems we still get some failures on macOS:

https://github.com/php/php-src/actions/runs/8746998656/job/24004796765

========DIFF========
--
       string(%d) "%S"
       ["members"]=>
     %a
008+     [0]=>
009+     string(4) "root"
010+     [1]=>
011+     string(6) "runner"
012+   }
       ["gid"]=>
       int(20)
     }
     bool(false)
017+ 
018+ Termsig=11
========DONE========
FAIL Test posix_getgrnam() function : basic functionality [ext/posix/tests/posix_getgrnam_basic.phpt] 

[devnexen]

Speaking of macos @iluuu1994 I was unable to reproduce for days the phar module segfault occurring only on intel arch, I have a arm64 version.

[iluuu1994]

@devnexen Ok, that's unfortunate. Thank you nonetheless. I will try to add ASAN to CI for macOS today, maybe that will help with identification of the issues.

[arnaud-lb]

@iluuu1994

@arnaud-lb It seems we still get some failures on macOS:

https://github.com/php/php-src/actions/runs/8746998656/job/24004796765

I wasn't able to reproduce this one in various configurations including in Valgrind/ASAN. Please let me know if it fails again, I will take an other look.

[iluuu1994]

@arnaud-lb Did you try a release build? That's what seems to be failing on CI (NTS).

[arnaud-lb]

Yes, I actually tried both but no luck