Merge pull request #5423 from Luv-Ray/fix-pathchk-issue5314

`pathchk`: check empty path by default

src/uu/pathchk/src/pathchk.rs

@@ -193,6 +193,17 @@ fn check_default(path: &[String]) -> bool {
         );
         return false;
     }
+    if total_len == 0 {
+        // Check whether a file name component is in a directory that is not searchable,
+        // or has some other serious problem. POSIX does not allow "" as a file name,
+        // but some non-POSIX hosts do (as an alias for "."),
+        // so allow "" if `symlink_metadata` (corresponds to `lstat`) does.
+        if fs::symlink_metadata(&joined_path).is_err() {
+            writeln!(std::io::stderr(), "pathchk: '': No such file or directory",);
+            return false;
+        }
+    }
+
     // components: length
     for p in path {
         let component_len = p.len();

tests/by-util/test_pathchk.rs

@@ -19,8 +19,16 @@ fn test_default_mode() {
     // accept non-portable chars
     new_ucmd!().args(&["dir#/$file"]).succeeds().no_stdout();
 
-    // accept empty path
-    new_ucmd!().args(&[""]).succeeds().no_stdout();
+    // fail on empty path
+    new_ucmd!()
+        .args(&[""])
+        .fails()
+        .stderr_only("pathchk: '': No such file or directory\n");
+
+    new_ucmd!().args(&["", ""]).fails().stderr_only(
+        "pathchk: '': No such file or directory\n\
+        pathchk: '': No such file or directory\n",
+    );
 
     // fail on long path
     new_ucmd!()