Return error when moving a source directory to a target directory which contains a subdirectory with the same name as the source (#6284)

Fixes #6275

Signed-off-by: nibon7 <nibon7@163.com>

crates/nu-command/src/filesystem/mv.rs

@@ -120,6 +120,21 @@ impl Command for Mv {
             ));
         }
 
+        if source.is_dir() && destination.is_dir() {
+            if let Some(name) = source.file_name() {
+                let dst = destination.join(name);
+                if dst.is_dir() {
+                    return Err(ShellError::GenericError(
+                        format!("Can't move {:?} to {:?}", source, dst),
+                        "Directory not empty".into(),
+                        Some(spanned_destination.span),
+                        None,
+                        Vec::new(),
+                    ));
+                }
+            }
+        }
+
         let some_if_source_is_destination = sources
             .iter()
             .find(|f| matches!(f, Ok(f) if destination.starts_with(f)));

crates/nu-command/tests/commands/move_/mv.rs

@@ -375,3 +375,21 @@ fn mv_ignores_ansi() {
         assert_eq!(actual.out, "success.txt");
     })
 }
+
+#[test]
+fn mv_directory_with_same_name() {
+    Playground::setup("mv_test_directory_with_same_name", |_dirs, sandbox| {
+        sandbox.mkdir("testdir");
+        sandbox.mkdir("testdir/testdir");
+
+        let cwd = sandbox.cwd().join("testdir");
+        let actual = nu!(
+            cwd,
+            r#"
+                 mv testdir ..
+            "#
+        );
+
+        assert!(actual.err.contains("Directory not empty"));
+    })
+}