cp: --rem don't fail if dest is hardlink to source

src/uu/cp/src/cp.rs

@@ -33,8 +33,8 @@ use platform::copy_on_write;
 use uucore::display::Quotable;
 use uucore::error::{set_exit_code, UClapError, UError, UResult, UUsageError};
 use uucore::fs::{
-    canonicalize, is_symlink_loop, paths_refer_to_same_file, FileInformation, MissingHandling,
-    ResolveMode,
+    are_hardlinks_to_same_file, canonicalize, is_symlink_loop, paths_refer_to_same_file,
+    FileInformation, MissingHandling, ResolveMode,
 };
 use uucore::{backup_control, update_control};
 // These are exposed for projects (e.g. nushell) that want to create an `Options` value, which
@@ -1657,6 +1657,15 @@ fn copy_file(
         }
     }
 
+    if are_hardlinks_to_same_file(source, dest)
+        && matches!(
+            options.overwrite,
+            OverwriteMode::Clobber(ClobberMode::RemoveDestination)
+        )
+    {
+        fs::remove_file(dest)?;
+    }
+
     if file_or_link_exists(dest) {
         handle_existing_dest(source, dest, options, source_in_command_line)?;
     }

tests/by-util/test_cp.rs

@@ -2827,6 +2827,24 @@ fn test_cp_mode_hardlink_no_dereference() {
     assert_eq!(at.read_symlink("z"), "slink");
 }
 
+#[cfg(not(any(windows, target_os = "android")))]
+#[test]
+fn test_remove_destination_with_destination_being_a_hardlink_to_source() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let file = "file";
+    let hardlink = "hardlink";
+
+    at.touch(file);
+    at.hard_link(file, hardlink);
+
+    ucmd.args(&["--remove-destination", file, hardlink])
+        .succeeds();
+
+    assert_eq!("", at.resolve_link(hardlink));
+    assert!(at.file_exists(file));
+    assert!(at.file_exists(hardlink));
+}
+
 #[test]
 fn test_remove_destination_with_destination_being_a_symlink_to_source() {
     let (at, mut ucmd) = at_and_ucmd!();