Fix ls: panicking on dangling symlink with --color=auto -l (#6346)

* Fixed unwrap being called on dereferenced dangling symlink

* Added test

* Switched to regex matching in test

* Remove unnecessary mkdir call

* Modified documentation of the test and added assertion of the colors

* Fixed a typo

src/uu/ls/src/ls.rs

@@ -3353,10 +3353,9 @@ fn color_name(
         // use the optional target_symlink
         // Use fn get_metadata_with_deref_opt instead of get_metadata() here because ls
         // should not exit with an err, if we are unable to obtain the target_metadata
-        let md = get_metadata_with_deref_opt(target.p_buf.as_path(), path.must_dereference)
-            .unwrap_or_else(|_| target.get_metadata(out).unwrap().clone());
-
-        apply_style_based_on_metadata(path, Some(&md), ls_colors, style_manager, &name)
+        let md_res = get_metadata_with_deref_opt(target.p_buf.as_path(), path.must_dereference);
+        let md = md_res.or(path.p_buf.symlink_metadata());
+        apply_style_based_on_metadata(path, md.ok().as_ref(), ls_colors, style_manager, &name)
     } else {
         let md_option = path.get_metadata(out);
         let symlink_metadata = path.p_buf.symlink_metadata().ok();

tests/by-util/test_ls.rs

@@ -2,7 +2,7 @@
 //
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
-// spell-checker:ignore (words) READMECAREFULLY birthtime doesntexist oneline somebackup lrwx somefile somegroup somehiddenbackup somehiddenfile tabsize aaaaaaaa bbbb cccc dddddddd ncccc neee naaaaa nbcdef nfffff dired subdired tmpfs mdir COLORTERM mexe bcdef
+// spell-checker:ignore (words) READMECAREFULLY birthtime doesntexist oneline somebackup lrwx somefile somegroup somehiddenbackup somehiddenfile tabsize aaaaaaaa bbbb cccc dddddddd ncccc neee naaaaa nbcdef nfffff dired subdired tmpfs mdir COLORTERM mexe bcdef mfoo
 
 #[cfg(any(unix, feature = "feat_selinux"))]
 use crate::common::util::expected_result;
@@ -1376,6 +1376,44 @@ fn test_ls_long_symlink_color() {
     }
 }
 
+/// This test is for "ls -l --color=auto|--color=always"
+/// We use "--color=always" as the colors are the same regardless of the color option being "auto" or "always"
+/// tests whether the specific color of the target and the dangling_symlink are equal and checks
+/// whether checks whether ls outputs the correct path for the symlink and the file it points to and applies the color code to it.
+#[test]
+fn test_ls_long_dangling_symlink_color() {
+    let ts = TestScenario::new(util_name!());
+    let at = &ts.fixtures;
+
+    at.mkdir("dir1");
+    at.symlink_dir("foo", "dir1/dangling_symlink");
+    let result = ts
+        .ucmd()
+        .arg("-l")
+        .arg("--color=always")
+        .arg("dir1/dangling_symlink")
+        .succeeds();
+
+    let stdout = result.stdout_str();
+    // stdout contains output like in the below sequence. We match for the color i.e. 01;36
+    // \x1b[0m\x1b[01;36mdir1/dangling_symlink\x1b[0m -> \x1b[01;36mfoo\x1b[0m
+    let color_regex = Regex::new(r"(\d\d;)\d\dm").unwrap();
+    // colors_vec[0] contains the symlink color and style and colors_vec[1] contains the color and style of the file the
+    // symlink points to.
+    let colors_vec: Vec<_> = color_regex
+        .find_iter(stdout)
+        .map(|color| color.as_str())
+        .collect();
+
+    assert_eq!(colors_vec[0], colors_vec[1]);
+    // constructs the string of file path with the color code
+    let symlink_color_name = colors_vec[0].to_owned() + "dir1/dangling_symlink\x1b";
+    let target_color_name = colors_vec[1].to_owned() + at.plus_as_string("foo\x1b").as_str();
+
+    assert!(stdout.contains(&symlink_color_name));
+    assert!(stdout.contains(&target_color_name));
+}
+
 #[test]
 fn test_ls_long_total_size() {
     let scene = TestScenario::new(util_name!());