From ed087e1fa449a9cc4ccb0cfc950578049f1a1f87 Mon Sep 17 00:00:00 2001
From: Felipe Coury <felipe.coury@gmail.com>
Date: Mon, 16 Feb 2026 23:29:51 -0300
Subject: [PATCH] fix(tui): avoid committing transient stream tail cells

---
 codex-rs/tui/src/chatwidget.rs                | 15 ++++--
 .../src/chatwidget/tests/status_and_layout.rs | 47 +++++++++++++++++++
 2 files changed, 57 insertions(+), 5 deletions(-)

diff --git a/codex-rs/tui/src/chatwidget.rs b/codex-rs/tui/src/chatwidget.rs
index c80c3fcb6c..48b801f98d 100644
--- a/codex-rs/tui/src/chatwidget.rs
+++ b/codex-rs/tui/src/chatwidget.rs
@@ -5567,12 +5567,17 @@ impl ChatWidget {
     }
 
     fn flush_active_cell(&mut self) {
-        if self.stream_controller.is_some()
-            && self
-                .active_cell
-                .as_ref()
-                .is_some_and(|cell| cell.as_any().is::<history_cell::StreamingAgentTailCell>())
+        if self
+            .active_cell
+            .as_ref()
+            .is_some_and(|cell| cell.as_any().is::<history_cell::StreamingAgentTailCell>())
         {
+            if self.stream_controller.is_some() {
+                return;
+            }
+            // If stream cleanup already cleared the controller, drop the transient tail instead
+            // of committing preview-only content to transcript history.
+            self.active_cell.take();
             return;
         }
 
diff --git a/codex-rs/tui/src/chatwidget/tests/status_and_layout.rs b/codex-rs/tui/src/chatwidget/tests/status_and_layout.rs
index 503e9d7375..2bc75f67ee 100644
--- a/codex-rs/tui/src/chatwidget/tests/status_and_layout.rs
+++ b/codex-rs/tui/src/chatwidget/tests/status_and_layout.rs
@@ -126,6 +126,53 @@ async fn current_stream_width_returns_none_when_reserved_columns_exhaust_width()
     assert_eq!(chat.current_stream_width(4), Some(1));
 }
 
+#[tokio::test]
+async fn add_to_history_does_not_commit_transient_stream_tail_after_controller_clear() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(None).await;
+
+    chat.active_cell = Some(Box::new(
+        crate::history_cell::StreamingAgentTailCell::new(
+            vec![ratatui::text::Line::from("transient table tail preview")],
+            true,
+        ),
+    ));
+    // Interrupt/error cleanup paths clear the controller before appending history.
+    chat.stream_controller = None;
+
+    chat.add_to_history(crate::history_cell::new_error_event(
+        "stream interrupted".to_string(),
+    ));
+
+    let mut inserted_count = 0usize;
+    let mut saw_transient_tail = false;
+    let mut saw_error = false;
+    while let Ok(event) = rx.try_recv() {
+        if let AppEvent::InsertHistoryCell(cell) = event {
+            inserted_count += 1;
+            if cell
+                .as_any()
+                .is::<crate::history_cell::StreamingAgentTailCell>()
+            {
+                saw_transient_tail = true;
+            }
+            let rendered = lines_to_single_string(&cell.display_lines(80));
+            if rendered.contains("stream interrupted") {
+                saw_error = true;
+            }
+        }
+    }
+
+    assert!(saw_error, "expected error history cell to be emitted");
+    assert!(
+        !saw_transient_tail,
+        "did not expect transient stream-tail cell to be committed",
+    );
+    assert_eq!(
+        inserted_count, 1,
+        "expected only one committed history cell after cleanup"
+    );
+}
+
 #[tokio::test]
 async fn helpers_are_available_and_do_not_panic() {
     let (tx_raw, _rx) = unbounded_channel::<AppEvent>();