From 45b023cd831688bc18761fccadac8abfe509e47e Mon Sep 17 00:00:00 2001
From: Ant39140 <ant258751@gmail.com>
Date: Thu, 13 Aug 2026 22:13:37 +0800
Subject: [PATCH] fix(tui): keep btw panels out of scrollback

---
 packages/coding-agent/CHANGELOG.md            |  4 ++
 .../src/modes/interactive-mode.ts             | 12 +++--
 packages/tui/test/component-render.test.ts    | 45 +++++++++++++++++++
 3 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 14334fddd..ed6d72538 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed repeated `/btw` panels committing transient frames to native scrollback and replaying conversation history after dismissal.
+
 ## [17.3.0] - 2026-08-13
 
 ### Breaking Changes
diff --git a/packages/coding-agent/src/modes/interactive-mode.ts b/packages/coding-agent/src/modes/interactive-mode.ts
index acf8f49d4..226af077b 100644
--- a/packages/coding-agent/src/modes/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive-mode.ts
@@ -376,16 +376,20 @@ export interface InteractiveModeOptions {
 /**
  * Anchored live-region container for the HUD/status rows between the transcript
  * and the editor (working loader, todo + subagent HUDs, transient notification
- * panels). While it has content every row is live: it reports a seam at 0 so the
- * engine never commits these anchored, rebuilt-in-place rows to native
- * scrollback — otherwise stale duplicates pile up above the live copy on short
- * terminals once the loader sits below a tall HUD. The transcript's own seam,
+ * panels). While it has content every row is live: it reports a seam at 0 and
+ * pins that live region so the engine never commits these anchored,
+ * rebuilt-in-place rows to native scrollback — otherwise stale duplicates pile
+ * up above the live copy on short terminals once the loader sits below a tall HUD. The transcript's own seam,
  * when present, sits higher and wins (topmost-seam merge in TUI.render).
  */
 class AnchoredLiveContainer extends Container implements NativeScrollbackLiveRegion {
 	getNativeScrollbackLiveRegionStart(): number | undefined {
 		return this.children.length > 0 ? 0 : undefined;
 	}
+
+	isNativeScrollbackLiveRegionPinned(): boolean {
+		return true;
+	}
 }
 
 /**
diff --git a/packages/tui/test/component-render.test.ts b/packages/tui/test/component-render.test.ts
index 0d6fd6950..15ad5cfc3 100644
--- a/packages/tui/test/component-render.test.ts
+++ b/packages/tui/test/component-render.test.ts
@@ -2,6 +2,7 @@ import { afterEach, beforeEach, describe, expect, it } from "bun:test";
 import {
 	type Component,
 	Container,
+	CURSOR_MARKER,
 	Editor,
 	type Focusable,
 	type NativeScrollbackCommittedRows,
@@ -71,6 +72,10 @@ class AnchoredStatusContainer extends Container implements NativeScrollbackLiveR
 		const hasAnchoredRows = this.children.length > 0;
 		return hasAnchoredRows ? 0 : undefined;
 	}
+
+	isNativeScrollbackLiveRegionPinned(): boolean {
+		return true;
+	}
 }
 
 function strip(rows: string[]): string[] {
@@ -351,6 +356,46 @@ describe("TUI.requestComponentRender", () => {
 			await term.flush();
 		}
 	});
+	it("keeps removed pinned panels and repeated transcript copies out of scrollback", async () => {
+		const term = new VirtualTerminal(40, 8, 1_000);
+		const scheduler = new StressRenderScheduler();
+		const tui = new TUI(term, undefined, { renderScheduler: scheduler });
+		const markers = Array.from({ length: 5 }, (_unused, index) => `HIST-${index}`);
+		const transcript = new CountingLines(markers);
+		const status = new AnchoredStatusContainer();
+		const editor = new CountingLines([`editor${CURSOR_MARKER}`]);
+		tui.addChild(transcript);
+		tui.addChild(status);
+		tui.addChild(editor);
+
+		try {
+			tui.start();
+			await scheduler.drain(term);
+			for (let cycle = 1; cycle <= 3; cycle++) {
+				const panel = new CountingLines([`panel-${cycle}-0`]);
+				status.addChild(panel);
+				tui.requestRender();
+				await scheduler.drain(term);
+				for (let tick = 1; tick <= 8; tick++) {
+					panel.set(Array.from({ length: tick + 1 }, (_row, index) => `panel-${cycle}-${tick}-${index}`));
+					tui.requestComponentRender(panel);
+					await scheduler.drain(term);
+				}
+				status.clear();
+				tui.requestRender();
+				await scheduler.drain(term);
+			}
+
+			const buffer = strip(term.getScrollBuffer()).join("\n");
+			for (const marker of markers) {
+				expect(buffer.split(marker)).toHaveLength(2);
+			}
+			expect(buffer).not.toContain("panel-");
+		} finally {
+			tui.stop();
+			await term.flush();
+		}
+	});
 });
 
 describe("TUI keystroke-scoped render", () => {