mv: moving dangling symlinks into directories (#8064)

* Fix linting and style issues

* Change condition to not fail for dangling symlinks

The function `move_files_into_dir` had a condition that failed when a
dangling symlink was moved into a folder, which resulted in a file
or directory doesn't exist error

* Added a test case

src/uu/mv/src/mv.rs

@@ -526,7 +526,7 @@ fn move_files_into_dir(files: &[PathBuf], target_dir: &Path, options: &Options)
     };
 
     for sourcepath in files {
-        if !sourcepath.exists() {
+        if sourcepath.symlink_metadata().is_err() {
             show!(MvError::NoSuchFile(sourcepath.quote().to_string()));
             continue;
         }

tests/by-util/test_mv.rs

@@ -443,6 +443,19 @@ fn test_mv_same_hardlink() {
         .stderr_is(format!("mv: '{file_a}' and '{file_b}' are the same file\n"));
 }
 
+#[test]
+#[cfg(all(unix, not(target_os = "android")))]
+fn test_mv_dangling_symlink_to_folder() {
+    let (at, mut ucmd) = at_and_ucmd!();
+
+    at.symlink_file("404", "abc");
+    at.mkdir("x");
+
+    ucmd.arg("abc").arg("x").succeeds();
+
+    assert!(at.symlink_exists("x/abc"));
+}
+
 #[test]
 #[cfg(all(unix, not(target_os = "android")))]
 fn test_mv_same_symlink() {