bug: fix CLI UP/ENTER (#4944)

Clear the history cursor before checking for duplicate submissions so
sending the same message twice exits history mode. This prevents Up/Down
from staying stuck in history browsing after duplicate sends.

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

@@ -59,14 +59,15 @@ impl ChatComposerHistory {
             return;
         }
 
+        self.history_cursor = None;
+        self.last_history_text = None;
+
         // Avoid inserting a duplicate if identical to the previous entry.
         if self.local_history.last().is_some_and(|prev| prev == text) {
             return;
         }
 
         self.local_history.push(text.to_string());
-        self.history_cursor = None;
-        self.last_history_text = None;
     }
 
     /// Should Up/Down key presses be interpreted as history navigation given

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

@@ -615,6 +615,35 @@ fn alt_up_edits_most_recent_queued_message() {
     );
 }
 
+/// Pressing Up to recall the most recent history entry and immediately queuing
+/// it while a task is running should always enqueue the same text, even when it
+/// is queued repeatedly.
+#[test]
+fn enqueueing_history_prompt_multiple_times_is_stable() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual();
+
+    // Submit an initial prompt to seed history.
+    chat.bottom_pane.set_composer_text("repeat me".to_string());
+    chat.handle_key_event(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
+
+    // Simulate an active task so further submissions are queued.
+    chat.bottom_pane.set_task_running(true);
+
+    for _ in 0..3 {
+        // Recall the prompt from history and ensure it is what we expect.
+        chat.handle_key_event(KeyEvent::new(KeyCode::Up, KeyModifiers::NONE));
+        assert_eq!(chat.bottom_pane.composer_text(), "repeat me");
+
+        // Queue the prompt while the task is running.
+        chat.handle_key_event(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
+    }
+
+    assert_eq!(chat.queued_user_messages.len(), 3);
+    for message in chat.queued_user_messages.iter() {
+        assert_eq!(message.text, "repeat me");
+    }
+}
+
 #[test]
 fn streaming_final_answer_keeps_task_running_state() {
     let (mut chat, _rx, mut op_rx) = make_chatwidget_manual();