From 95a737b592147f9dffd4ab94e481c0cc432ad899 Mon Sep 17 00:00:00 2001
From: liushiao <liushiao@bytedance.com>
Date: Wed, 27 May 2026 11:47:03 +0800
Subject: [PATCH] fix(tui): clear footer row before rendering statusline

---
 crates/tui/src/tui/widgets/footer.rs | 43 +++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/crates/tui/src/tui/widgets/footer.rs b/crates/tui/src/tui/widgets/footer.rs
index 27f13aa7..6efdfb94 100644
--- a/crates/tui/src/tui/widgets/footer.rs
+++ b/crates/tui/src/tui/widgets/footer.rs
@@ -11,7 +11,7 @@ use ratatui::{
     layout::Rect,
     style::{Color, Style},
     text::{Line, Span},
-    widgets::{Paragraph, Widget},
+    widgets::{Block, Paragraph, Widget},
 };
 use unicode_width::UnicodeWidthStr;
 
@@ -573,6 +573,13 @@ impl Renderable for FooterWidget {
             return;
         }
 
+        // Repaint the whole footer row first so stale transcript glyphs from
+        // the previous frame cannot survive in cells this frame's spans do not
+        // touch (#2244).
+        Block::default()
+            .style(Style::default().bg(self.props.footer_bg))
+            .render(area, buf);
+
         let preview_left_spans = self.left_spans(available_width);
         let preview_left_width = span_width(&preview_left_spans);
         let right_budget = available_width
@@ -652,6 +659,8 @@ mod tests {
     use crate::palette;
     use crate::tui::app::{App, AppMode, TuiOptions};
     use ratatui::{
+        buffer::Buffer,
+        layout::Rect,
         style::{Color, Style},
         text::Span,
     };
@@ -1377,4 +1386,36 @@ mod tests {
         assert!(!rendered.contains("agent"));
         assert!(!rendered.contains("deepseek-v4-flash"));
     }
+
+    #[test]
+    fn render_clears_stale_cells_across_entire_footer_row() {
+        let app = make_app();
+        let widget = FooterWidget::new(idle_props_for(&app));
+        let area = Rect::new(0, 0, 48, 1);
+        let mut buf = Buffer::empty(area);
+
+        for x in area.x..area.x.saturating_add(area.width) {
+            buf[(x, area.y)]
+                .set_symbol("X")
+                .set_style(Style::default().fg(Color::Red).bg(Color::Blue));
+        }
+
+        widget.render(area, &mut buf);
+
+        let rendered: String = (area.x..area.x.saturating_add(area.width))
+            .map(|x| buf[(x, area.y)].symbol())
+            .collect();
+
+        assert!(
+            !rendered.contains('X'),
+            "footer render must clear stale row content before painting: {rendered:?}"
+        );
+        for x in area.x..area.x.saturating_add(area.width) {
+            assert_eq!(
+                buf[(x, area.y)].bg,
+                app.ui_theme.footer_bg,
+                "footer background should cover the full row"
+            );
+        }
+    }
 }