Clippy fixes for toolchain bump (#13497)

- **Suggested default impl for the new `*Stack`s**
- **Change a hashmap to make clippy happy**
- **Clone from fix**
- **Fix conditional unused in test**
- then **Bump rust toolchain**

crates/nu-cli/src/util.rs

@@ -321,16 +321,10 @@ mod test {
 
         let env = engine_state.render_env_vars();
 
-        assert!(
-            matches!(env.get(&"FOO".to_string()), Some(&Value::String { val, .. }) if val == "foo")
-        );
-        assert!(
-            matches!(env.get(&"SYMBOLS".to_string()), Some(&Value::String { val, .. }) if val == symbols)
-        );
-        assert!(
-            matches!(env.get(&symbols.to_string()), Some(&Value::String { val, .. }) if val == "symbols")
-        );
-        assert!(env.get(&"PWD".to_string()).is_some());
+        assert!(matches!(env.get("FOO"), Some(&Value::String { val, .. }) if val == "foo"));
+        assert!(matches!(env.get("SYMBOLS"), Some(&Value::String { val, .. }) if val == symbols));
+        assert!(matches!(env.get(symbols), Some(&Value::String { val, .. }) if val == "symbols"));
+        assert!(env.contains_key("PWD"));
         assert_eq!(env.len(), 4);
     }
 }

crates/nu-command/tests/commands/rm.rs

@@ -1,8 +1,10 @@
+#[cfg(not(windows))]
 use nu_path::AbsolutePath;
 use nu_test_support::fs::{files_exist_at, Stub::EmptyFile};
 use nu_test_support::nu;
 use nu_test_support::playground::Playground;
 use rstest::rstest;
+#[cfg(not(windows))]
 use std::fs;
 use std::path::Path;
 
@@ -405,16 +407,19 @@ fn removes_file_after_cd() {
     })
 }
 
+#[cfg(not(windows))]
 struct Cleanup<'a> {
     dir_to_clean: &'a AbsolutePath,
 }
 
+#[cfg(not(windows))]
 fn set_dir_read_only(directory: &AbsolutePath, read_only: bool) {
     let mut permissions = fs::metadata(directory).unwrap().permissions();
     permissions.set_readonly(read_only);
     fs::set_permissions(directory, permissions).expect("failed to set directory permissions");
 }
 
+#[cfg(not(windows))]
 impl<'a> Drop for Cleanup<'a> {
     /// Restores write permissions to the given directory so that the Playground can be successfully
     /// cleaned up.

crates/nu-engine/src/eval.rs

@@ -198,7 +198,7 @@ pub fn redirect_env(engine_state: &EngineState, caller_stack: &mut Stack, callee
     }
 
     // set config to callee config, to capture any updates to that
-    caller_stack.config = callee_stack.config.clone();
+    caller_stack.config.clone_from(&callee_stack.config);
 }
 
 fn eval_external(

crates/nu-protocol/src/engine/argument.rs

@@ -71,7 +71,7 @@ impl Argument {
 }
 
 /// Stores the argument context for calls in IR evaluation.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct ArgumentStack {
     arguments: Vec<Argument>,
 }

crates/nu-protocol/src/engine/engine_state.rs

@@ -428,13 +428,13 @@ impl EngineState {
             .1
     }
 
-    pub fn render_env_vars(&self) -> HashMap<&String, &Value> {
-        let mut result = HashMap::new();
+    pub fn render_env_vars(&self) -> HashMap<&str, &Value> {
+        let mut result: HashMap<&str, &Value> = HashMap::new();
 
         for overlay_name in self.active_overlay_names(&[]) {
             let name = String::from_utf8_lossy(overlay_name);
             if let Some(env_vars) = self.env_vars.get(name.as_ref()) {
-                result.extend(env_vars);
+                result.extend(env_vars.iter().map(|(k, v)| (k.as_str(), v)));
             }
         }
 

crates/nu-protocol/src/engine/error_handler.rs

@@ -10,7 +10,7 @@ pub struct ErrorHandler {
 }
 
 /// Keeps track of error handlers pushed during evaluation of an IR block.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct ErrorHandlerStack {
     handlers: Vec<ErrorHandler>,
 }