Fix hooks on 0.92.0 (#12383)

# Description
Fixes #12382, where overlay changes from hooks were not preserved into
the global state. This was due to creating child stacks for hooks, when
the global stack should have been used instead.

crates/nu-cli/src/repl.rs

@@ -267,7 +267,7 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
     );
 
     start_time = std::time::Instant::now();
-    //Reset the ctrl-c handler
+    // Reset the ctrl-c handler
     if let Some(ctrlc) = &mut engine_state.ctrlc {
         ctrlc.store(false, Ordering::SeqCst);
     }
@@ -281,10 +281,42 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
     );
 
     start_time = std::time::Instant::now();
+    // Right before we start our prompt and take input from the user,
+    // fire the "pre_prompt" hook
+    if let Some(hook) = engine_state.get_config().hooks.pre_prompt.clone() {
+        if let Err(err) = eval_hook(engine_state, &mut stack, None, vec![], &hook, "pre_prompt") {
+            report_error_new(engine_state, &err);
+        }
+    }
+    perf(
+        "pre-prompt hook",
+        start_time,
+        file!(),
+        line!(),
+        column!(),
+        use_color,
+    );
+
+    start_time = std::time::Instant::now();
+    // Next, check all the environment variables they ask for
+    // fire the "env_change" hook
+    let env_change = engine_state.get_config().hooks.env_change.clone();
+    if let Err(error) = hook::eval_env_change_hook(env_change, engine_state, &mut stack) {
+        report_error_new(engine_state, &error)
+    }
+    perf(
+        "env-change hook",
+        start_time,
+        file!(),
+        line!(),
+        column!(),
+        use_color,
+    );
+
+    let engine_reference = Arc::new(engine_state.clone());
     let config = engine_state.get_config();
 
-    let engine_reference = std::sync::Arc::new(engine_state.clone());
-
+    start_time = std::time::Instant::now();
     // Find the configured cursor shapes for each mode
     let cursor_config = CursorConfig {
         vi_insert: map_nucursorshape_to_cursorshape(config.cursor_shape_vi_insert),
@@ -304,7 +336,7 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
     // at this line we have cloned the state for the completer and the transient prompt
     // until we drop those, we cannot use the stack in the REPL loop itself
     // See STACK-REFERENCE to see where we have taken a reference
-    let mut stack_arc = Arc::new(stack);
+    let stack_arc = Arc::new(stack);
 
     let mut line_editor = line_editor
         .use_kitty_keyboard_enhancement(config.use_kitty_protocol)
@@ -427,50 +459,6 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
         use_color,
     );
 
-    start_time = std::time::Instant::now();
-    // Right before we start our prompt and take input from the user,
-    // fire the "pre_prompt" hook
-    if let Some(hook) = config.hooks.pre_prompt.clone() {
-        if let Err(err) = eval_hook(
-            engine_state,
-            &mut Stack::with_parent(stack_arc.clone()),
-            None,
-            vec![],
-            &hook,
-            "pre_prompt",
-        ) {
-            report_error_new(engine_state, &err);
-        }
-    }
-    perf(
-        "pre-prompt hook",
-        start_time,
-        file!(),
-        line!(),
-        column!(),
-        use_color,
-    );
-
-    start_time = std::time::Instant::now();
-    // Next, check all the environment variables they ask for
-    // fire the "env_change" hook
-    let config = engine_state.get_config();
-    if let Err(error) = hook::eval_env_change_hook(
-        config.hooks.env_change.clone(),
-        engine_state,
-        &mut Stack::with_parent(stack_arc.clone()),
-    ) {
-        report_error_new(engine_state, &error)
-    }
-    perf(
-        "env-change hook",
-        start_time,
-        file!(),
-        line!(),
-        column!(),
-        use_color,
-    );
-
     start_time = std::time::Instant::now();
     let config = &engine_state.get_config().clone();
     prompt_update::update_prompt(
@@ -508,6 +496,8 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
         .with_completer(Box::<DefaultCompleter>::default());
     let shell_integration = config.shell_integration;
 
+    let mut stack = Stack::unwrap_unique(stack_arc);
+
     match input {
         Ok(Signal::Success(s)) => {
             let hostname = System::host_name();
@@ -530,7 +520,7 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
 
                 if let Err(err) = eval_hook(
                     engine_state,
-                    &mut Stack::with_parent(stack_arc.clone()),
+                    &mut stack,
                     None,
                     vec![],
                     &hook,
@@ -552,8 +542,6 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
             // Actual command execution logic starts from here
             let start_time = Instant::now();
 
-            let mut stack = Stack::unwrap_unique(stack_arc);
-
             match parse_operation(s.clone(), engine_state, &stack) {
                 Ok(operation) => match operation {
                     ReplOperation::AutoCd { cwd, target, span } => {
@@ -598,22 +586,20 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
             }
 
             flush_engine_state_repl_buffer(engine_state, &mut line_editor);
-            // put the stack back into the arc
-            stack_arc = Arc::new(stack);
         }
         Ok(Signal::CtrlC) => {
             // `Reedline` clears the line content. New prompt is shown
             if shell_integration {
-                run_ansi_sequence(&get_command_finished_marker(&stack_arc, engine_state));
+                run_ansi_sequence(&get_command_finished_marker(&stack, engine_state));
             }
         }
         Ok(Signal::CtrlD) => {
             // When exiting clear to a new line
             if shell_integration {
-                run_ansi_sequence(&get_command_finished_marker(&stack_arc, engine_state));
+                run_ansi_sequence(&get_command_finished_marker(&stack, engine_state));
             }
             println!();
-            return (false, Stack::unwrap_unique(stack_arc), line_editor);
+            return (false, stack, line_editor);
         }
         Err(err) => {
             let message = err.to_string();
@@ -625,7 +611,7 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
                 // Alternatively only allow that expected failures let the REPL loop
             }
             if shell_integration {
-                run_ansi_sequence(&get_command_finished_marker(&stack_arc, engine_state));
+                run_ansi_sequence(&get_command_finished_marker(&stack, engine_state));
             }
         }
     }
@@ -647,7 +633,7 @@ fn loop_iteration(ctx: LoopContext) -> (bool, Stack, Reedline) {
         use_color,
     );
 
-    (true, Stack::unwrap_unique(stack_arc), line_editor)
+    (true, stack, line_editor)
 }
 
 ///

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

@@ -125,9 +125,9 @@ impl Stack {
         unique_stack.env_vars = child.env_vars;
         unique_stack.env_hidden = child.env_hidden;
         unique_stack.active_overlays = child.active_overlays;
-        for item in child.parent_deletions.into_iter() {
-            unique_stack.vars.remove(item);
-        }
+        unique_stack
+            .vars
+            .retain(|(var, _)| !child.parent_deletions.contains(var));
         unique_stack
     }
     pub fn with_env(

tests/hooks/mod.rs

@@ -551,3 +551,16 @@ fn err_hook_parse_error() {
     assert!(actual_repl.err.contains("unsupported_config_value"));
     assert_eq!(actual_repl.out, "");
 }
+
+#[test]
+fn env_change_overlay() {
+    let inp = &[
+        "module test { export-env { $env.BAR = 2 } }",
+        &env_change_hook_code("FOO", "'overlay use test'"),
+        "$env.FOO = 1",
+        "$env.BAR",
+    ];
+
+    let actual_repl = nu!(nu_repl_code(inp));
+    assert_eq!(actual_repl.out, "2");
+}