rmdir: Remove all trailing slashes when checking for symlinks (#9983)

* rmdir: Remove all trailing slashes when checking for symlinks

rmdir: cargo fmt

l

* rmdir: Extract removal of trailing slashes to helper func

* rmdir: Add regression test for removal of trailing slashes when checking for symlink

* rmdir: add cfg flag to helper func which is only used on unix

src/uu/rmdir/src/rmdir.rs

@@ -66,10 +66,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                     Ok(path.metadata()?.file_type().is_dir())
                 }
 
-                let bytes = path.as_os_str().as_bytes();
+                let mut bytes = path.as_os_str().as_bytes();
                 if error.raw_os_error() == Some(libc::ENOTDIR) && bytes.ends_with(b"/") {
                     // Strip the trailing slash or .symlink_metadata() will follow the symlink
-                    let no_slash: &Path = OsStr::from_bytes(&bytes[..bytes.len() - 1]).as_ref();
+                    bytes = strip_trailing_slashes_from_path(bytes);
+                    let no_slash: &Path = OsStr::from_bytes(bytes).as_ref();
                     if no_slash.is_symlink() && points_to_directory(no_slash).unwrap_or(true) {
                         show_error!(
                             "{}",
@@ -119,6 +120,15 @@ fn remove_single(path: &Path, opts: Opts) -> Result<(), Error<'_>> {
     remove_dir(path).map_err(|error| Error { error, path })
 }
 
+#[cfg(unix)]
+fn strip_trailing_slashes_from_path(path: &[u8]) -> &[u8] {
+    let mut end = path.len();
+    while end > 0 && path[end - 1] == b'/' {
+        end -= 1;
+    }
+    &path[..end]
+}
+
 // POSIX: https://pubs.opengroup.org/onlinepubs/009696799/functions/rmdir.html
 #[cfg(not(windows))]
 const NOT_EMPTY_CODES: &[i32] = &[libc::ENOTEMPTY, libc::EEXIST];

tests/by-util/test_rmdir.rs

@@ -243,3 +243,18 @@ fn test_rmdir_remove_symlink_dangling() {
         .fails()
         .stderr_is("rmdir: failed to remove 'dl/': Symbolic link not followed\n");
 }
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+#[test]
+fn test_rmdir_remove_symlink_dir_with_trailing_slashes() {
+    // a symlink with trailing slashes should still be printing the 'Symbolic link not followed'
+    // message
+    let (at, mut ucmd) = at_and_ucmd!();
+
+    at.mkdir("dir");
+    at.symlink_dir("dir", "dl");
+
+    ucmd.arg("dl////")
+        .fails()
+        .stderr_is("rmdir: failed to remove 'dl////': Symbolic link not followed\n");
+}