Various improvements to chroot

[sylvestre]

Try to fix the issue skipped test: user nobody lacks execute permissions like
https://github.com/coreutils/coreutils/blob/master/tests/cp/special-bits.sh#L45

(but this line fails as it is parsed as cp -p c c2 is part of the chroot args

[sylvestre]

And glad we are now testing chroot for real :)

[tertsdiepraam]

I'm not sure I fully understand the --skip-chdir implementation. It seems to me that --skip-chdir implies that the chdir never happens, not that it still happens and is then restored?

[sylvestre]

You are correct :)
we do it internally to make sure that the chroot(".") works but, in the chroot, we are back in the initial dir

[tertsdiepraam]

Hmm I see, so we can't do something like this?

let err = unsafe {
    chroot(CString::new(root).unwrap().as_bytes_with_nul().as_ptr() as *const libc::c_char)
};
// some error handling
if !skip_chdir {
    std::env::set_current_dir(root).unwrap();
}

[sylvestre]

I tried this but it didn't work (but maybe it is my fault). I will have a look again

[sylvestre]

Yeah:
Warning: Changes from 'main': PASS +1 / FAIL +7 / ERROR +0 / SKIP -8

[sylvestre]

Hmm I see, so we can't do something like this?

worked great, thanks :)