MS-Windows problem reported by Bruno Haible in:
https://lists.gnu.org/r/bug-gnulib/2022-06/msg00041.html
Although I don’t use MS-Windows I see some related fstatat etc.
problems and am trying to fix them with this further patch.
* lib/fchmodat.c (fchmodat):
* lib/lchmod.c (lchmod):
* lib/lchown.c (lchown)
[!HAVE_LCHOWN && HAVE_CHOWN && !CHOWN_MODIFIES_SYMLINK]:
* lib/renameatu.c (renameatu)
[HAVE_RENAME && RENAME_TRAILING_SLASH_SOURCE_BUG]:
Use readlinkat/readlink instead of fstatat/lstat to test merely
whether a string names a symlink, as this avoids problems
with EOVERFLOW. Also, I hope it works around the MS-Windows
issues that Bruno noted.
* m4/fchmodat.m4 (gl_PREREQ_FCHMODAT):
Check for readlinkat, not lchmod.
* m4/lchmod.m4 (gl_FUNC_LCHMOD): Do not require AC_CANONICAL_HOST
or check for lstat.
(gl_PREREQ_LCHMOD): Check for readlink.
* modules/lchown (Depends-on): Add readlink. Do not depend on
lstat merely because !HAVE_LCHOWN.
* modules/renameatu (Depends-on): Add fstatat, readlinkat.