feat: ctrl-d only exits when there is no user input (#1589)

While this does make it so that `ctrl-d` will not exit Codex when the
composer is not empty, `ctrl-d` will still exit Codex if it is in the
"working" state.

Fixes https://github.com/openai/codex/issues/1443.

codex-rs/tui/src/app.rs

@@ -199,7 +199,21 @@ impl<'a> App<'a> {
                             modifiers: crossterm::event::KeyModifiers::CONTROL,
                             ..
                         } => {
-                            self.app_event_tx.send(AppEvent::ExitRequest);
+                            match &mut self.app_state {
+                                AppState::Chat { widget } => {
+                                    if widget.composer_is_empty() {
+                                        self.app_event_tx.send(AppEvent::ExitRequest);
+                                    } else {
+                                        // Treat Ctrl+D as a normal key event when the composer
+                                        // is not empty so that it doesn't quit the application
+                                        // prematurely.
+                                        self.dispatch_key_event(key_event);
+                                    }
+                                }
+                                AppState::Login { .. } | AppState::GitWarning { .. } => {
+                                    self.app_event_tx.send(AppEvent::ExitRequest);
+                                }
+                            }
                         }
                         _ => {
                             self.dispatch_key_event(key_event);

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

@@ -76,6 +76,11 @@ impl ChatComposer<'_> {
         this
     }
 
+    /// Returns true if the composer currently contains no user input.
+    pub(crate) fn is_empty(&self) -> bool {
+        self.textarea.is_empty()
+    }
+
     /// Update the cached *context-left* percentage and refresh the placeholder
     /// text. The UI relies on the placeholder to convey the remaining
     /// context when the composer is empty.

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

@@ -72,8 +72,7 @@ impl ChatComposerHistory {
             return false;
         }
 
-        let lines = textarea.lines();
-        if lines.len() == 1 && lines[0].is_empty() {
+        if textarea.is_empty() {
             return true;
         }
 
@@ -85,6 +84,7 @@ impl ChatComposerHistory {
             return false;
         }
 
+        let lines = textarea.lines();
         matches!(&self.last_history_text, Some(prev) if prev == &lines.join("\n"))
     }
 

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

@@ -162,6 +162,10 @@ impl BottomPane<'_> {
         }
     }
 
+    pub(crate) fn composer_is_empty(&self) -> bool {
+        self.composer.is_empty()
+    }
+
     pub(crate) fn is_task_running(&self) -> bool {
         self.is_task_running
     }

codex-rs/tui/src/chatwidget.rs

@@ -432,6 +432,10 @@ impl ChatWidget<'_> {
         }
     }
 
+    pub(crate) fn composer_is_empty(&self) -> bool {
+        self.bottom_pane.composer_is_empty()
+    }
+
     /// Forward an `Op` directly to codex.
     pub(crate) fn submit_op(&self, op: Op) {
         if let Err(e) = self.codex_op_tx.send(op) {