fix(tui): stabilize tab status detail updates

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

@@ -59,6 +59,7 @@ mod request_user_input;
 mod status_line_setup;
 mod status_line_style;
 mod status_surface_preview;
+mod tab_status_detail;
 mod tab_status_state;
 mod title_setup;
 pub(crate) use action_required_title::ACTION_REQUIRED_PREVIEW_PREFIX;
@@ -328,54 +329,6 @@ impl BottomPane {
         }
     }
 
-    fn desired_tab_status(&self) -> (TabStatus, Option<String>) {
-        let class = self.desired_tab_class();
-        let detail = match class {
-            TabStatus::Waiting => self
-                .active_view()
-                .and_then(BottomPaneView::tab_status_detail),
-            TabStatus::Working => self.working_tab_status_detail(),
-            TabStatus::Idle => self
-                .tab_status
-                .last_activity()
-                .map(|activity| format!("last: {activity}")),
-        };
-        (class, detail)
-    }
-
-    fn working_tab_status_detail(&self) -> Option<String> {
-        let mut parts = Vec::new();
-        if let Some(activity) = self.tab_status.current_activity() {
-            parts.push(activity.to_string());
-        }
-        let push_if_new = |parts: &mut Vec<String>, candidate: &str| {
-            let candidate = candidate.trim();
-            if candidate.is_empty()
-                || parts
-                    .iter()
-                    .any(|part| part.contains(candidate) || candidate.contains(part.as_str()))
-            {
-                return;
-            }
-            parts.push(candidate.to_string());
-        };
-        if let Some(status) = self.status.as_ref() {
-            let header = status.header();
-            if header != "Working" {
-                push_if_new(&mut parts, header);
-            }
-            if let Some(first_line) = status.details().and_then(|details| details.lines().next()) {
-                push_if_new(&mut parts, first_line);
-            }
-        }
-        if !parts.is_empty() {
-            return Some(parts.join(" • "));
-        }
-        self.tab_status
-            .last_activity()
-            .map(|activity| format!("after: {activity}"))
-    }
-
     fn refresh_tab_status(&mut self) {
         self.refresh_tab_status_at(Instant::now());
     }

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

@@ -0,0 +1,53 @@
+use super::BottomPane;
+use super::BottomPaneView;
+use crate::tab_status::TabStatus;
+
+impl BottomPane {
+    pub(super) fn desired_tab_status(&self) -> (TabStatus, Option<String>) {
+        let class = self.desired_tab_class();
+        let detail = match class {
+            TabStatus::Waiting => self
+                .active_view()
+                .and_then(BottomPaneView::tab_status_detail),
+            TabStatus::Working => self.working_tab_status_detail(),
+            TabStatus::Idle => self
+                .tab_status
+                .last_activity()
+                .map(|activity| format!("last: {activity}")),
+        };
+        (class, detail)
+    }
+
+    fn working_tab_status_detail(&self) -> Option<String> {
+        let mut parts = Vec::new();
+        if let Some(activity) = self.tab_status.current_activity() {
+            parts.push(activity.to_string());
+        }
+        let push_if_new = |parts: &mut Vec<String>, candidate: &str| {
+            let candidate = candidate.trim();
+            if candidate.is_empty()
+                || parts
+                    .iter()
+                    .any(|part| part.contains(candidate) || candidate.contains(part.as_str()))
+            {
+                return;
+            }
+            parts.push(candidate.to_string());
+        };
+        if let Some(status) = self.status.as_ref() {
+            let header = status.header();
+            if header != "Working" {
+                push_if_new(&mut parts, header);
+            }
+            if let Some(first_line) = status.details().and_then(|details| details.lines().next()) {
+                push_if_new(&mut parts, first_line);
+            }
+        }
+        if !parts.is_empty() {
+            return Some(parts.join(" • "));
+        }
+        self.tab_status
+            .last_activity()
+            .map(|activity| format!("after: {activity}"))
+    }
+}

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

@@ -80,7 +80,6 @@ impl TabStatusState {
             return;
         }
         if self.last_status.as_ref() == Some(&desired) {
-            self.last_emit_at = Some(now);
             return;
         }
         if let Err(err) = set_tab_status(desired.0, desired.1.as_deref()) {

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

@@ -43,7 +43,7 @@ fn throttle_defers_detail_changes_but_not_status_changes() {
 }
 
 #[test]
-fn equal_refresh_rearms_the_detail_throttle() {
+fn equal_refresh_does_not_rearm_the_detail_throttle() {
     let mut state = TabStatusState::new();
     let started_at = Instant::now();
     let unchanged_at = started_at + Duration::from_millis(/*millis*/ 300);
@@ -56,6 +56,6 @@ fn equal_refresh_rearms_the_detail_throttle() {
             TabStatus::Working,
             unchanged_at + Duration::from_millis(/*millis*/ 100)
         ),
-        Some(Duration::from_millis(/*millis*/ 150))
+        None
     );
 }

codex-rs/tui/src/tab_status.rs

@@ -131,12 +131,16 @@ pub(crate) fn clear_tab_status() -> io::Result<()> {
 }
 
 fn sanitize_detail(detail: &str) -> String {
-    let mut out = String::with_capacity(detail.len());
+    let mut out = String::with_capacity(detail.len().min(MAX_TAB_STATUS_DETAIL_CHARS * 2 + 1));
     let mut chars_written = 0;
     let mut pending_space = false;
     let mut truncated = false;
 
     for ch in detail.chars() {
+        if chars_written >= MAX_TAB_STATUS_DETAIL_CHARS {
+            truncated = true;
+            break;
+        }
         if ch.is_whitespace() {
             pending_space = !out.is_empty();
             continue;

codex-rs/tui/src/tab_status_tests.rs

@@ -50,6 +50,16 @@ fn detail_is_safe_bounded_osc_text() {
         MAX_TAB_STATUS_DETAIL_CHARS * 2 + 1
     );
     assert!(sanitized.ends_with('…'));
+
+    let sanitized = sanitize_detail(&format!(
+        "{}{}tail",
+        "x".repeat(MAX_TAB_STATUS_DETAIL_CHARS),
+        " \u{202E}".repeat(/*n*/ 10_000)
+    ));
+    assert_eq!(
+        sanitized,
+        format!("{}…", "x".repeat(MAX_TAB_STATUS_DETAIL_CHARS))
+    );
 }
 
 #[test]