fix(terminal): a woken pane's new prompt starts on its own line when reattached (#33494)

After Wake the window paints the restored history and then blanks its viewport, so the new
shell's prompt starts on a clean screen. The daemon's own copy of the screen, seeded with the
same history, skipped that step. A later reattach (a reload, a second window, the phone)
therefore showed the new prompt beside the dead shell's last one: `p7/sub$ orca@awin:~/projects/p7$`
(awin verify-11). The seed now ends with the same viewport blanking the window writes, built by
one shared function, after the process-boundary ground, which still never moves the cursor.

Co-authored-by: Claude <noreply@anthropic.com>

src/main/daemon/process-boundary-ground.test.ts

@@ -103,13 +103,23 @@ describe('process boundary ground at a cold restore', () => {
     expect(checkpoint.snapshotAnsi).not.toContain('\x1b[?66h')
   })
 
-  it('keeps the cursor where the recovered history left it', () => {
+  it('grounds without moving the cursor', () => {
+    const live = emulator(DAEMON_SESSION_SCROLLBACK_ROWS)
+    write(live, 'OLD_OUTPUT_1\r\n$ ')
+    write(live, PROCESS_BOUNDARY_GROUND)
+    write(live, 'X')
+    expect(live.getBufferTailLines(24)[1]).toBe('$ X')
+  })
+
+  // awin verify-11: a reattach after Wake showed the new prompt beside the dead shell's (`$ $`).
+  it("starts the new shell's prompt on its own line, keeping the recovered history", () => {
     const live = seededLive(checkpointOfDeadProcess(''))
     write(live, 'NEW_SHELL_PROMPT')
 
-    const rows = live.getBufferTailLines(24)
-    expect(rows[0]).toBe('OLD_OUTPUT_1')
-    expect(rows[2]).toBe('$ NEW_SHELL_PROMPT')
+    const rows = live.getBufferTailLines(60).filter((row) => row.length > 0)
+    expect(rows.slice(0, 2)).toEqual(['OLD_OUTPUT_1', 'OLD_OUTPUT_2'])
+    expect(rows.some((row) => row.trim() === '$')).toBe(true)
+    expect(rows.at(-1)).toBe('NEW_SHELL_PROMPT')
   })
 
   it('never lets the new shell complete a torn escape from the dead process', () => {

src/main/daemon/terminal-history-seed-segments.test.ts

@@ -6,6 +6,7 @@ import {
   PROCESS_BOUNDARY_GROUND,
   RESET_GRAPHIC_RENDITION
 } from '../../shared/terminal-mode-reset-profiles'
+import { buildFreshShellViewportBlankingSequence } from '../../shared/terminal-fresh-shell-viewport'
 import type { ColdRestoreInfo } from './terminal-history-cold-restore-info'
 import type { TerminalModes } from './types'
 
@@ -20,6 +21,7 @@ const ARMED_MODES: TerminalModes = {
 
 // Assert seed placement here; terminal-mode-reset-profiles.test.ts pins the reset bytes.
 const GROUND = PROCESS_BOUNDARY_GROUND
+const FRESH_VIEWPORT = buildFreshShellViewportBlankingSequence(24)
 
 function restoreInfo(overrides: Partial<ColdRestoreInfo> = {}): ColdRestoreInfo {
   return {
@@ -42,7 +44,8 @@ describe('getRecoveredHistorySeedSegments', () => {
     expect(segments).toEqual([
       `${RESET_GRAPHIC_RENDITION}\x1b[?1003h\x1b[?1006h`,
       'user@host ~ $ \x1b[?1003h',
-      GROUND
+      GROUND,
+      FRESH_VIEWPORT
     ])
   })
 
@@ -51,7 +54,7 @@ describe('getRecoveredHistorySeedSegments', () => {
       getRecoveredHistorySeedSegments(
         restoreInfo({ modes: { ...ARMED_MODES, alternateScreen: true } })
       )
-    ).toEqual([`${RESET_GRAPHIC_RENDITION}user@host ~ $ `, GROUND])
+    ).toEqual([`${RESET_GRAPHIC_RENDITION}user@host ~ $ `, GROUND, FRESH_VIEWPORT])
   })
 
   it('stays empty when there is no recovered normal buffer', () => {

src/main/daemon/terminal-history-seed-segments.ts

@@ -3,6 +3,7 @@ import {
   PROCESS_BOUNDARY_GROUND,
   RESET_GRAPHIC_RENDITION
 } from '../../shared/terminal-mode-reset-profiles'
+import { buildFreshShellViewportBlankingSequence } from '../../shared/terminal-fresh-shell-viewport'
 
 // Reset modes after seeding the daemon too, or downstream snapshots (including mobile) re-arm dead TUI state.
 
@@ -10,7 +11,11 @@ export function getRecoveredHistorySeedSegments(restoreInfo: ColdRestoreInfo): r
   if (restoreInfo.modes.alternateScreen) {
     const normalBuffer = restoreInfo.scrollbackAnsi || restoreInfo.snapshotAnsi
     return normalBuffer
-      ? [`${RESET_GRAPHIC_RENDITION}${normalBuffer}`, PROCESS_BOUNDARY_GROUND]
+      ? [
+          `${RESET_GRAPHIC_RENDITION}${normalBuffer}`,
+          PROCESS_BOUNDARY_GROUND,
+          freshShellViewport(restoreInfo)
+        ]
       : []
   }
   const recovered = [restoreInfo.rehydrateSequences, restoreInfo.snapshotAnsi].filter(
@@ -25,6 +30,13 @@ export function getRecoveredHistorySeedSegments(restoreInfo: ColdRestoreInfo): r
   return [
     `${RESET_GRAPHIC_RENDITION}${firstRecovered}`,
     ...remainingRecovered,
-    PROCESS_BOUNDARY_GROUND
+    PROCESS_BOUNDARY_GROUND,
+    freshShellViewport(restoreInfo)
   ]
 }
+
+// Why: the window blanks its viewport after painting a restore, but the daemon's seeded screen
+// did not, so a reattach showed the new shell's prompt beside the old one (`$ $`).
+function freshShellViewport(restoreInfo: ColdRestoreInfo): string {
+  return buildFreshShellViewportBlankingSequence(restoreInfo.rows)
+}

src/renderer/src/components/terminal-pane/pty-connection-cold-restore-repaint.spec.ts

@@ -7,7 +7,7 @@ import {
 } from '../../../../shared/terminal-mode-reset-profiles'
 import { Terminal } from '@xterm/headless'
 import { ORCA_LAYOUT_OWNER_IS_MAIN } from '../../../../shared/layout-owner-switch'
-import { buildFreshShellViewportBlankingSequence } from './terminal-restored-viewport'
+import { buildFreshShellViewportBlankingSequence } from '../../../../shared/terminal-fresh-shell-viewport'
 import {
   flushAsyncTicks,
   writeHeadlessTerminal,

src/renderer/src/components/terminal-pane/pty-connection/fresh-spawn-follow-reset.ts

@@ -8,7 +8,7 @@ import {
   POST_REPLAY_REATTACH_RESET_KEEP_MOUSE,
   buildKittyKeyboardRestore
 } from '../../../../../shared/terminal-mode-reset-profiles'
-import { buildFreshShellViewportBlankingSequence } from '../terminal-restored-viewport'
+import { buildFreshShellViewportBlankingSequence } from '../../../../../shared/terminal-fresh-shell-viewport'
 import { flushTerminalOutput } from '@/lib/pane-manager/pane-terminal-output-scheduler'
 import {
   getTerminalScrollIntentKind,

src/renderer/src/components/terminal-pane/terminal-restored-viewport.test.ts

@@ -1,7 +1,7 @@
 import { Terminal } from '@xterm/headless'
 import { describe, expect, it } from 'vitest'
 
-import { buildFreshShellViewportBlankingSequence } from './terminal-restored-viewport'
+import { buildFreshShellViewportBlankingSequence } from '../../../../shared/terminal-fresh-shell-viewport'
 
 function writeTerminal(term: Terminal, data: string): Promise<void> {
   return new Promise((resolve) => term.write(data, resolve))

src/renderer/src/components/terminal-pane/terminal-restored-viewport.ts

@@ -1,10 +1,3 @@
 import type { RefObject } from 'react'
 
 export type RestoredViewportBlankingPanesRef = RefObject<Set<number>>
-
-export function buildFreshShellViewportBlankingSequence(rows: number): string {
-  const viewportRows = Math.max(1, Math.floor(Number.isFinite(rows) ? rows : 24))
-  // Why: newline scrolling preserves restored rows in xterm scrollback; CSI S
-  // drops them. Reset margins first so stale TUI scroll regions cannot trap it.
-  return `\x1b[?6l\x1b[r\x1b[${viewportRows};1H${'\r\n'.repeat(viewportRows)}\x1b[H`
-}

src/shared/terminal-fresh-shell-viewport.ts

@@ -0,0 +1,10 @@
+/**
+ * Scrolls a restored screen into scrollback and homes the cursor, so a fresh shell's first prompt
+ * starts on a blank viewport instead of beside the dead shell's last prompt.
+ */
+export function buildFreshShellViewportBlankingSequence(rows: number): string {
+  const viewportRows = Math.max(1, Math.floor(Number.isFinite(rows) ? rows : 24))
+  // Why: newline scrolling preserves restored rows in xterm scrollback; CSI S
+  // drops them. Reset margins first so stale TUI scroll regions cannot trap it.
+  return `\x1b[?6l\x1b[r\x1b[${viewportRows};1H${'\r\n'.repeat(viewportRows)}\x1b[H`
+}