cp: use libc stat for destination check to support LD_PRELOAD tests

Author: ChrisDryden

src/uu/cp/src/cp.rs

@@ -1390,8 +1390,7 @@ pub fn copy(sources: &[PathBuf], target: &Path, options: &Options) -> CopyResult
             let dest = construct_dest_path(source, target, target_type, options)
                 .unwrap_or_else(|_| target.to_path_buf());
 
-            if fs::metadata(&dest).is_ok()
-                && !fs::symlink_metadata(&dest)?.file_type().is_symlink()
+            if FileInformation::from_path(&dest, false).is_ok_and(|info| !info.is_symlink())
                 // if both `source` and `dest` are symlinks, it should be considered as an overwrite.
                 || fs::metadata(source).is_ok()
                     && fs::symlink_metadata(source)?.file_type().is_symlink()

src/uucore/src/lib/features/fs.rs

@@ -166,6 +166,12 @@ impl FileInformation {
         #[cfg(any(target_os = "netbsd", not(target_pointer_width = "64")))]
         return self.0.st_ino.into();
     }
+
+    /// Returns true if the file is a symbolic link.
+    #[cfg(unix)]
+    pub fn is_symlink(&self) -> bool {
+        (self.0.st_mode as mode_t & S_IFMT) == S_IFLNK
+    }
 }
 
 #[cfg(unix)]

tests/by-util/test_cp.rs

@@ -3118,7 +3118,7 @@ fn test_cp_archive_on_nonexistent_file() {
         .arg(TEST_EXISTING_FILE)
         .fails()
         .stderr_only(
-            "cp: cannot stat 'nonexistent_file.txt': No such file or directory (os error 2)\n",
+            "cp: cannot stat 'nonexistent_file.txt': No such file or directory\n",
         );
 }