From d2ce1c5ff1b76c7ce5cc680d516ccc6ec07ec281 Mon Sep 17 00:00:00 2001
From: Jinwoo-H <jinwoo0825@gmail.com>
Date: Wed, 29 Apr 2026 00:12:13 -0400
Subject: [PATCH] fix mobile terminal replay row mismatch

Co-authored-by: Orca <help@stably.ai>
---
 .../app/h/[hostId]/session/[worktreeId].tsx   | 26 +++++++++++++++++--
 mobile/src/terminal/TerminalWebView.tsx       | 11 ++++++--
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/mobile/app/h/[hostId]/session/[worktreeId].tsx b/mobile/app/h/[hostId]/session/[worktreeId].tsx
index f36274c54ad..be01823fe65 100644
--- a/mobile/app/h/[hostId]/session/[worktreeId].tsx
+++ b/mobile/app/h/[hostId]/session/[worktreeId].tsx
@@ -69,11 +69,13 @@ const STATUS_LABELS: Record<ConnectionState, string> = {
 function TerminalPaneView({
   handle,
   active,
-  onRef
+  onRef,
+  onWebReady
 }: {
   handle: string
   active: boolean
   onRef: (handle: string, ref: TerminalWebViewHandle | null) => void
+  onWebReady: (handle: string) => void
 }) {
   const setRef = useCallback(
     (ref: TerminalWebViewHandle | null) => {
@@ -87,7 +89,11 @@ function TerminalPaneView({
       pointerEvents={active ? 'auto' : 'none'}
       style={[styles.terminalPane, !active && styles.terminalPaneHidden]}
     >
-      <TerminalWebView ref={setRef} style={styles.terminalWebView} />
+      <TerminalWebView
+        ref={setRef}
+        style={styles.terminalWebView}
+        onWebReady={() => onWebReady(handle)}
+      />
     </View>
   )
 }
@@ -541,6 +547,21 @@ export default function SessionScreen() {
     [subscribeToTerminal]
   )
 
+  const handleTerminalWebReady = useCallback(
+    (handle: string) => {
+      if (!initializedHandlesRef.current.has(handle)) {
+        return
+      }
+      // Why: the native WebView can reload independently of the session
+      // screen during Metro reloads or Android process churn. The old xterm
+      // buffer is gone, so force a fresh scrollback snapshot for this handle.
+      unsubscribeTerminal(handle)
+      initializedHandlesRef.current.delete(handle)
+      subscribeToTerminal(handle)
+    },
+    [subscribeToTerminal, unsubscribeTerminal]
+  )
+
   async function handleSend() {
     if (!client || !activeHandle || !input.trim()) return
 
@@ -771,6 +792,7 @@ export default function SessionScreen() {
               handle={terminal.handle}
               active={terminal.handle === activeHandle}
               onRef={setTerminalWebViewRef}
+              onWebReady={handleTerminalWebReady}
             />
           ))}
         </View>
diff --git a/mobile/src/terminal/TerminalWebView.tsx b/mobile/src/terminal/TerminalWebView.tsx
index 11806e000ff..5d8b84466b5 100644
--- a/mobile/src/terminal/TerminalWebView.tsx
+++ b/mobile/src/terminal/TerminalWebView.tsx
@@ -14,6 +14,7 @@ export type TerminalWebViewHandle = {
 
 type Props = {
   style?: StyleProp<ViewStyle>
+  onWebReady?: () => void
 }
 
 type TerminalMessage =
@@ -138,6 +139,11 @@ const XTERM_HTML = `<!DOCTYPE html>
   // managed by xterm, not a separate HTML gap. Never shrink below the
   // original init row count to avoid clipping active terminal content.
   function adjustRowsForViewport() {
+    // Why: mobile replays a live PTY snapshot and then applies live cursor-
+    // relative chunks from that same PTY. Resizing only the WebView xterm
+    // changes cursor coordinates and makes TUI repaint chunks duplicate or
+    // overlap existing frames. Keep xterm rows identical to the PTY.
+    return;
     if (!term || !term.element) return;
     // Why: active alternate-screen TUIs (Claude Code, vim, etc.) are exact
     // screen snapshots. Locally resizing the mobile xterm after replay can
@@ -495,7 +501,7 @@ const XTERM_HTML = `<!DOCTYPE html>
 </html>`
 
 export const TerminalWebView = forwardRef<TerminalWebViewHandle, Props>(function TerminalWebView(
-  { style },
+  { style, onWebReady },
   ref
 ) {
   const webViewRef = useRef<WebView>(null)
@@ -541,6 +547,7 @@ export const TerminalWebView = forwardRef<TerminalWebViewHandle, Props>(function
 
       if (msg.type === 'web-ready') {
         isWebReadyRef.current = true
+        onWebReady?.()
         flushPendingMessages()
       } else if (msg.type === 'measure-result') {
         const resolve = measureResolveRef.current
@@ -552,7 +559,7 @@ export const TerminalWebView = forwardRef<TerminalWebViewHandle, Props>(function
         }
       }
     },
-    [flushPendingMessages]
+    [flushPendingMessages, onWebReady]
   )
 
   const handleLoadStart = useCallback(() => {