ln: accept non-utf8 source names in target-dir modes (#11403)

* ln: accept non-utf8 source names in target-dir modes

* ln: remove unused ln-error-cannot-stat locale strings

tests/by-util/test_ln.rs

@@ -378,6 +378,51 @@ fn test_symlink_target_dir() {
     assert_eq!(at.resolve_link(file_b_link), file_b);
 }
 
+#[test]
+#[cfg(target_os = "linux")]
+fn test_symlink_target_dir_non_utf8_source_name() {
+    use std::ffi::OsStr;
+    use std::fs;
+    use std::os::unix::ffi::OsStrExt;
+
+    let scene = TestScenario::new(util_name!());
+    let at = &scene.fixtures;
+    let target_dir = "test_symlink_target_dir_non_utf8";
+    let source_bytes = b"source_\xFF\xFE";
+    let source_name = OsStr::from_bytes(source_bytes);
+
+    at.mkdir(target_dir);
+    at.touch(source_name);
+
+    scene
+        .ucmd()
+        .args(&["-s", "-t", target_dir])
+        .arg(source_name)
+        .succeeds()
+        .no_stderr();
+
+    let target_dir_path = at.plus(target_dir);
+    let mut dir_entries = fs::read_dir(&target_dir_path)
+        .expect("reading target directory entries after creating symlink");
+    let created_entry = dir_entries
+        .next()
+        .expect("finding created entry in target directory")
+        .expect("reading created target-directory entry");
+    assert!(
+        dir_entries.next().is_none(),
+        "expected only one created entry in target directory"
+    );
+    assert_eq!(
+        created_entry.file_name().as_os_str().as_bytes(),
+        source_bytes
+    );
+
+    let created_link_path = target_dir_path.join(source_name);
+    let created_link_target = fs::read_link(&created_link_path)
+        .expect("reading created symlink target in target directory");
+    assert_eq!(created_link_target.as_os_str().as_bytes(), source_bytes);
+}
+
 #[test]
 fn test_symlink_target_dir_from_dir() {
     let (at, mut ucmd) = at_and_ucmd!();