chmod: errors with -R flag on dangling link but shouldn't

[jfinkels]

Environment: Ubuntu 24.04, uutils main branch (git commit 2430e2a), GNU coreutils v9.6.8-fbfd88-dirty

Steps to reproduce: Create a link to a file that doesn't exist and then try to change the link's permissions with the -R flag:

mkdir dir
ln -s target dangling-link  # target doesn't exist
chmod 755 --no-dereference -R -P dangling-link

What happens now: uutils chmod terminates with an error message

chmod: cannot operate on dangling symlink 'dangling-link'

What I expected to happen: GNU chmod succeeds with no output.

Notes: With both uutils and GNU, the permissions of the link itself are not actually changed, but I think that's expected for symbolic links:

$ ls -l dangling-link
lrwxrwxrwx 1 jeffrey jeffrey 6 Jan 26 10:51 dangling-link -> target

Also, the -R flag I think has no other effect in this test case, as there is no directory here to recurse into.

This is causing a failure in the GNU test file tests/chmod/symlinks.sh.

[wasiqibnzahid]

Hello, I am interested in solving this, would it be okay if I start working on this?
Thanks

[sylvestre]

Sure :)

[jfinkels]

The -P flag seems to be one of three new flags that control how symbolic links are traversed. From the --help:

The following options modify how a hierarchy is traversed when the -R
option is also specified.  If more than one is specified, only the final
one takes effect. -H is the default.

  -H                     if a command line argument is a symbolic link
                         to a directory, traverse it
  -L                     traverse every symbolic link to a directory
                         encountered
  -P                     do not traverse any symbolic links