Merge pull request #3972 from jfinkels/cp-symbolic-link-loop

cp: allow removing symbolic link loop destination

src/uu/cp/src/cp.rs

@@ -1372,6 +1372,15 @@ fn handle_existing_dest(
     Ok(())
 }
 
+/// Decide whether the given path exists.
+fn file_or_link_exists(path: &Path) -> bool {
+    // Using `Path.exists()` or `Path.try_exists()` is not sufficient,
+    // because if `path` is a symbolic link and there are too many
+    // levels of symbolic link, then those methods will return false
+    // or an OS error.
+    path.symlink_metadata().is_ok()
+}
+
 /// Copy the a file from `source` to `dest`. `source` will be dereferenced if
 /// `options.dereference` is set to true. `dest` will be dereferenced only if
 /// the source was not a symlink.
@@ -1389,7 +1398,7 @@ fn copy_file(
     symlinked_files: &mut HashSet<FileInformation>,
     source_in_command_line: bool,
 ) -> CopyResult<()> {
-    if dest.exists() {
+    if file_or_link_exists(dest) {
         handle_existing_dest(source, dest, options, source_in_command_line)?;
     }
 

tests/by-util/test_cp.rs

@@ -2096,6 +2096,19 @@ fn test_cp_mode_hardlink_no_dereference() {
     assert_eq!(at.read_symlink("z"), "slink");
 }
 
+#[test]
+fn test_remove_destination_symbolic_link_loop() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    at.symlink_file("loop", "loop");
+    at.plus("loop");
+    at.touch("f");
+    ucmd.args(&["--remove-destination", "f", "loop"])
+        .succeeds()
+        .no_stdout()
+        .no_stderr();
+    assert!(at.file_exists("loop"));
+}
+
 /// Test that copying a directory to itself is disallowed.
 #[test]
 fn test_copy_directory_to_itself_disallowed() {