Fix multiline paste in /goal edit (#26047)

Fixes #26025.

## Why
`/goal edit` opens `CustomPromptView`, which did not use the paste-burst
handling that protects the main composer when terminals deliver paste as
rapid key events. On Windows terminals, the first pasted newline could
be treated as Enter-to-submit, truncating the goal edit and leaving the
rest of the paste behind.

## What
This reuses `PasteBurst` in `CustomPromptView` as a lightweight
Enter-suppression detector for paste-like key streams. Characters still
insert directly, explicit paste still goes through the view paste path,
and ordinary text entry still submits on Enter.

codex-rs/tui/src/bottom_pane/custom_prompt_view.rs

@@ -11,7 +11,9 @@ use ratatui::widgets::Paragraph;
 use ratatui::widgets::StatefulWidgetRef;
 use ratatui::widgets::Widget;
 use std::cell::RefCell;
+use std::time::Instant;
 
+use crate::key_hint::has_ctrl_or_alt;
 use crate::render::renderable::Renderable;
 
 use super::popup_consts::standard_popup_hint_line;
@@ -19,6 +21,7 @@ use super::popup_consts::standard_popup_hint_line;
 use super::CancellationEvent;
 use super::bottom_pane_view::BottomPaneView;
 use super::bottom_pane_view::ViewCompletion;
+use super::paste_burst::PasteBurst;
 use super::textarea::TextArea;
 use super::textarea::TextAreaState;
 
@@ -35,6 +38,7 @@ pub(crate) struct CustomPromptView {
     // UI state
     textarea: TextArea,
     textarea_state: RefCell<TextAreaState>,
+    paste_burst: PasteBurst,
     completion: Option<ViewCompletion>,
 }
 
@@ -59,13 +63,12 @@ impl CustomPromptView {
             on_submit,
             textarea,
             textarea_state: RefCell::new(TextAreaState::default()),
+            paste_burst: PasteBurst::default(),
             completion: None,
         }
     }
-}
 
-impl BottomPaneView for CustomPromptView {
-    fn handle_key_event(&mut self, key_event: KeyEvent) {
+    fn handle_key_event_at(&mut self, key_event: KeyEvent, now: Instant) {
         match key_event {
             KeyEvent {
                 code: KeyCode::Esc, ..
@@ -74,26 +77,58 @@ impl BottomPaneView for CustomPromptView {
             }
             KeyEvent {
                 code: KeyCode::Enter,
-                modifiers: KeyModifiers::NONE,
+                modifiers,
                 ..
             } => {
-                let text = self.textarea.text().trim().to_string();
-                if !text.is_empty() {
-                    (self.on_submit)(text);
-                    self.completion = Some(ViewCompletion::Accepted);
+                if self.paste_burst.direct_insert_newline_should_insert(now) {
+                    self.paste_burst.extend_window(now);
+                    self.textarea.insert_str("\n");
+                    return;
+                }
+                if modifiers == KeyModifiers::NONE {
+                    let text = self.textarea.text().trim().to_string();
+                    if !text.is_empty() {
+                        (self.on_submit)(text);
+                        self.completion = Some(ViewCompletion::Accepted);
+                    }
+                } else {
+                    self.textarea.input(key_event);
                 }
             }
             KeyEvent {
-                code: KeyCode::Enter,
+                code: KeyCode::Char(_),
+                modifiers,
                 ..
-            } => {
+            } if !has_ctrl_or_alt(modifiers) && self.textarea.allows_paste_burst() => {
+                let paste_like_burst = self.paste_burst.on_plain_char_no_hold(now).is_some();
                 self.textarea.input(key_event);
+                if paste_like_burst {
+                    self.paste_burst.extend_window(now);
+                }
+            }
+            KeyEvent {
+                code: KeyCode::Tab,
+                modifiers,
+                ..
+            } if !has_ctrl_or_alt(modifiers) && self.textarea.allows_paste_burst() => {
+                let in_paste_burst = self.paste_burst.direct_insert_newline_should_insert(now);
+                self.textarea.input(key_event);
+                if in_paste_burst {
+                    self.paste_burst.extend_window(now);
+                }
             }
             other => {
                 self.textarea.input(other);
+                self.paste_burst.clear_after_explicit_paste();
             }
         }
     }
+}
+
+impl BottomPaneView for CustomPromptView {
+    fn handle_key_event(&mut self, key_event: KeyEvent) {
+        self.handle_key_event_at(key_event, Instant::now());
+    }
 
     fn on_ctrl_c(&mut self) -> CancellationEvent {
         self.completion = Some(ViewCompletion::Cancelled);
@@ -113,10 +148,15 @@ impl BottomPaneView for CustomPromptView {
             return false;
         }
         self.textarea.insert_str(&pasted);
+        self.paste_burst.clear_after_explicit_paste();
         true
     }
 }
 
+#[cfg(test)]
+#[path = "custom_prompt_view_tests.rs"]
+mod tests;
+
 impl Renderable for CustomPromptView {
     fn desired_height(&self, width: u16) -> u16 {
         let extra_top: u16 = if self.context_label.is_some() { 1 } else { 0 };

codex-rs/tui/src/bottom_pane/custom_prompt_view_tests.rs

@@ -0,0 +1,93 @@
+use super::*;
+use pretty_assertions::assert_eq;
+use std::sync::mpsc::Receiver;
+
+#[test]
+fn paste_burst_newline_does_not_submit_short_first_line() {
+    let now = Instant::now();
+
+    for (first_line, second_line) in [("x", "rest"), ("id", "body"), ("foo", "bar")] {
+        let (mut view, submitted_rx) = custom_prompt_view();
+        let mut ms = 0;
+
+        for ch in first_line.chars() {
+            view.handle_key_event_at(KeyEvent::from(KeyCode::Char(ch)), now + elapsed(ms));
+            ms += 1;
+        }
+        view.handle_key_event_at(KeyEvent::from(KeyCode::Enter), now + elapsed(ms));
+        ms += 1;
+        for ch in second_line.chars() {
+            view.handle_key_event_at(KeyEvent::from(KeyCode::Char(ch)), now + elapsed(ms));
+            ms += 1;
+        }
+
+        assert!(submitted_rx.try_recv().is_err());
+        assert!(!view.is_complete());
+
+        view.handle_key_event_at(KeyEvent::from(KeyCode::Enter), now + elapsed(/*ms*/ 200));
+
+        assert_eq!(
+            submitted_rx.try_recv(),
+            Ok(format!("{first_line}\n{second_line}"))
+        );
+        assert!(view.is_complete());
+    }
+}
+
+#[test]
+fn paste_burst_newline_after_tab_does_not_submit() {
+    let (mut view, submitted_rx) = custom_prompt_view();
+    let now = Instant::now();
+    let mut ms = 0;
+
+    view.handle_key_event_at(KeyEvent::from(KeyCode::Char('x')), now + elapsed(ms));
+    ms += 1;
+    view.handle_key_event_at(KeyEvent::from(KeyCode::Tab), now + elapsed(ms));
+    ms += 1;
+    view.handle_key_event_at(KeyEvent::from(KeyCode::Enter), now + elapsed(ms));
+    ms += 1;
+    for ch in "rest".chars() {
+        view.handle_key_event_at(KeyEvent::from(KeyCode::Char(ch)), now + elapsed(ms));
+        ms += 1;
+    }
+
+    assert!(submitted_rx.try_recv().is_err());
+    assert!(!view.is_complete());
+
+    view.handle_key_event_at(KeyEvent::from(KeyCode::Enter), now + elapsed(/*ms*/ 200));
+
+    assert_eq!(submitted_rx.try_recv(), Ok("x\nrest".to_string()));
+    assert!(view.is_complete());
+}
+
+#[test]
+fn delayed_enter_after_typing_submits() {
+    let (mut view, submitted_rx) = custom_prompt_view();
+    let now = Instant::now();
+
+    for (idx, ch) in "foo".chars().enumerate() {
+        view.handle_key_event_at(KeyEvent::from(KeyCode::Char(ch)), now + elapsed(idx * 20));
+    }
+    view.handle_key_event_at(KeyEvent::from(KeyCode::Enter), now + elapsed(/*ms*/ 80));
+
+    assert_eq!(submitted_rx.try_recv(), Ok("foo".to_string()));
+    assert!(view.is_complete());
+}
+
+fn custom_prompt_view() -> (CustomPromptView, Receiver<String>) {
+    let (submitted, submitted_rx) = std::sync::mpsc::channel();
+    let view = CustomPromptView::new(
+        "Edit goal".to_string(),
+        "Type a goal objective and press Enter".to_string(),
+        String::new(),
+        /*context_label*/ None,
+        Box::new(move |text| {
+            submitted.send(text).expect("send submitted text");
+        }),
+    );
+    (view, submitted_rx)
+}
+
+fn elapsed(ms: usize) -> std::time::Duration {
+    std::time::Duration::from_millis(ms as u64)
+}

codex-rs/tui/src/bottom_pane/paste_burst.rs

@@ -10,7 +10,7 @@
 //!   paste once enough chars have arrived.
 //!
 //! This module provides the `PasteBurst` state machine. `ChatComposer` feeds it only "plain"
-//! character events (no Ctrl/Alt) and uses its decisions to either:
+//! character events (no Ctrl/Alt) and uses the full buffering decisions to either:
 //!
 //! - briefly hold a first ASCII char (flicker suppression),
 //! - buffer a burst as a single pasted string, or
@@ -32,6 +32,10 @@
 //!   [`PasteBurst::flush_before_modified_input`] to avoid leaving buffered text "stuck", and then
 //!   [`PasteBurst::clear_window_after_non_char`] so subsequent typing does not get grouped into a
 //!   previous burst.
+//! - Direct-insert callers can skip buffering, use
+//!   [`PasteBurst::direct_insert_newline_should_insert`] in their Enter handler, and call
+//!   [`PasteBurst::extend_window`] when Enter or [`PasteBurst::on_plain_char_no_hold`] reports a
+//!   burst-like stream.
 //!
 //! # State Variables
 //!
@@ -106,10 +110,10 @@
 //! - [`PasteBurst::on_plain_char_no_hold`] never holds (used for IME/non-ASCII paths), since
 //!   holding a non-ASCII character can feel like dropped input.
 //!
-//! # Contract With `ChatComposer`
+//! # Contract With Callers
 //!
-//! `PasteBurst` does not mutate the UI text buffer on its own. The caller (`ChatComposer`) must
-//! interpret decisions and apply the corresponding UI edits:
+//! `PasteBurst` does not mutate the UI text buffer on its own. Callers must interpret decisions
+//! and apply the corresponding UI edits. `ChatComposer` uses the full buffering contract:
 //!
 //! - For each plain ASCII `KeyCode::Char`, call [`PasteBurst::on_plain_char`].
 //!   - [`CharDecision::RetainFirstChar`]: do **not** insert the char into the textarea yet.
@@ -333,6 +337,14 @@ impl PasteBurst {
         self.is_active() || in_burst_window
     }
 
+    /// Decide if Enter should insert a newline for callers that insert chars immediately.
+    pub fn direct_insert_newline_should_insert(&self, now: Instant) -> bool {
+        self.newline_should_insert_instead_of_submit(now)
+            || self
+                .last_plain_char_time
+                .is_some_and(|t| now.duration_since(t) <= PASTE_BURST_CHAR_INTERVAL)
+    }
+
     /// Keep the burst window alive.
     pub fn extend_window(&mut self, now: Instant) {
         self.burst_window_until = Some(now + PASTE_ENTER_SUPPRESS_WINDOW);

codex-rs/tui/src/chatwidget/tests/popups_and_settings.rs

@@ -333,16 +333,7 @@ async fn plugins_popup_add_marketplace_tab_opens_prompt_and_submits_source() {
         "expected marketplace source prompt, got:\n{prompt}"
     );
 
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('o'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('w'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('n'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('e'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('r'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('/'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('r'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('e'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('p'), KeyModifiers::NONE));
-    chat.handle_key_event(KeyEvent::new(KeyCode::Char('o'), KeyModifiers::NONE));
+    chat.handle_paste("owner/repo".to_string());
     chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
 
     match rx.try_recv() {