Skip safe hidden TUI renderer writes

src/renderer/src/components/terminal-pane/hidden-renderer-skip-eligibility.test.ts

@@ -61,7 +61,19 @@ describe('shouldSkipHiddenRendererOutput', () => {
     ).toBe(true)
   })
 
-  it('keeps startup query windows and terminal-control chunks live', () => {
+  it('skips safe hidden synchronized redraw chunks when a snapshot restore is available', () => {
+    expect(
+      shouldSkipHiddenRendererOutput({
+        foreground: false,
+        canRestoreHiddenOutput: true,
+        startupRendererQueryWindowActive: false,
+        synchronizedOutputActive: true,
+        data: '\x1b[?2026h\x1b[1;1H\x1b[2J\x1b[32mready\x1b[0m\x1b[?25l\x1b[?2026l\n'
+      })
+    ).toBe(true)
+  })
+
+  it('keeps startup query windows live', () => {
     expect(
       shouldSkipHiddenRendererOutput({
         foreground: false,
@@ -71,15 +83,6 @@ describe('shouldSkipHiddenRendererOutput', () => {
         data: 'plain\r\n'
       })
     ).toBe(false)
-    expect(
-      shouldSkipHiddenRendererOutput({
-        foreground: false,
-        canRestoreHiddenOutput: true,
-        startupRendererQueryWindowActive: false,
-        synchronizedOutputActive: true,
-        data: 'plain row inside synchronized frame\r\n'
-      })
-    ).toBe(false)
     expect(
       shouldSkipHiddenRendererOutput({
         foreground: false,
@@ -95,11 +98,25 @@ describe('shouldSkipHiddenRendererOutput', () => {
         canRestoreHiddenOutput: true,
         startupRendererQueryWindowActive: false,
         synchronizedOutputActive: false,
-        data: '\x1b[?2026hredraw\x1b[?2026l'
+        data: '\x1b[?1;2c'
       })
     ).toBe(false)
   })
 
+  it('keeps query and incomplete control chunks live', () => {
+    for (const data of ['\x1b[6n', '\x1b[c', '\x1b[?25', '\x1b[?1049h']) {
+      expect(
+        shouldSkipHiddenRendererOutput({
+          foreground: false,
+          canRestoreHiddenOutput: true,
+          startupRendererQueryWindowActive: false,
+          synchronizedOutputActive: false,
+          data
+        })
+      ).toBe(false)
+    }
+  })
+
   it('keeps non-title OSC and incomplete title OSC chunks live', () => {
     for (const data of ['\x1b]52;c;clipboard\x07', '\x1b]9;notify\x07', '\x1b]0;partial-title']) {
       expect(

src/renderer/src/components/terminal-pane/hidden-renderer-skip-eligibility.ts

@@ -36,11 +36,52 @@ function findTitleOscEnd(data: string, startIndex: number): number | null {
   return null
 }
 
+function findSafeCsiEnd(data: string, startIndex: number): number | null {
+  if (data.charCodeAt(startIndex) !== 0x1b || data.charCodeAt(startIndex + 1) !== 0x5b) {
+    return null
+  }
+
+  for (let index = startIndex + 2; index < data.length; index++) {
+    const code = data.charCodeAt(index)
+    if (code < 0x40 || code > 0x7e) {
+      continue
+    }
+    const body = data.slice(startIndex + 2, index)
+    const final = data[index]
+    if (isSafeHiddenRedrawCsi(body, final)) {
+      return index + 1
+    }
+    return null
+  }
+  return null
+}
+
+function isSafeHiddenRedrawCsi(body: string, final: string): boolean {
+  if (/[^0-9;?]/.test(body)) {
+    return false
+  }
+  if (final === 'h' || final === 'l') {
+    return body === '?2026' || body === '?25'
+  }
+  return (
+    final === 'm' ||
+    final === 'H' ||
+    final === 'f' ||
+    final === 'A' ||
+    final === 'B' ||
+    final === 'C' ||
+    final === 'D' ||
+    final === 'G' ||
+    final === 'J' ||
+    final === 'K'
+  )
+}
+
 function containsOnlyRestorableHiddenOutput(data: string): boolean {
   for (let index = 0; index < data.length; ) {
     const code = data.charCodeAt(index)
     if (code === 0x1b) {
-      const nextIndex = findTitleOscEnd(data, index)
+      const nextIndex = findTitleOscEnd(data, index) ?? findSafeCsiEnd(data, index)
       if (nextIndex === null) {
         return false
       }
@@ -66,14 +107,12 @@ export function shouldSkipHiddenRendererOutput({
   foreground,
   canRestoreHiddenOutput,
   startupRendererQueryWindowActive,
-  synchronizedOutputActive,
   data
 }: HiddenRendererSkipEligibility): boolean {
   if (
     foreground ||
     !canRestoreHiddenOutput ||
     startupRendererQueryWindowActive ||
-    synchronizedOutputActive ||
     data.length === 0
   ) {
     return false

src/renderer/src/components/terminal-pane/pty-connection.test.ts

@@ -2945,48 +2945,56 @@ describe('connectPanePty', () => {
     expect(transport.sendInput).not.toHaveBeenCalled()
   })
 
-  it('keeps hidden terminal-control bytes on the live xterm path', async () => {
-    const pendingTimeouts: (() => void)[] = []
-    const originalSetTimeout = globalThis.setTimeout
-    globalThis.setTimeout = vi.fn((fn: () => void) => {
-      pendingTimeouts.push(fn)
-      return 999 as unknown as ReturnType<typeof setTimeout>
-    }) as unknown as typeof setTimeout
+  it('restores safe hidden terminal-control bytes from the main snapshot', async () => {
+    const { connectPanePty } = await import('./pty-connection')
+    const transport = createMockTransport('pty-id')
+    const capturedDataCallback: {
+      current: ((data: string, meta?: { seq?: number; rawLength?: number }) => void) | null
+    } = { current: null }
+    transport.connect.mockImplementation(async ({ callbacks }: { callbacks: ConnectCallbacks }) => {
+      capturedDataCallback.current = callbacks.onData ?? null
+      return 'pty-id'
+    })
+    transportFactoryQueue.push(transport)
+    const getMainBufferSnapshot = window.api.pty.getMainBufferSnapshot as unknown as ReturnType<
+      typeof vi.fn
+    >
+    getMainBufferSnapshot.mockResolvedValue({
+      data: 'control snapshot\r\n',
+      cols: 100,
+      rows: 30,
+      seq: 64
+    })
 
-    try {
-      const { connectPanePty } = await import('./pty-connection')
-      const transport = createMockTransport('pty-id')
-      const capturedDataCallback: { current: ((data: string) => void) | null } = { current: null }
-      transport.connect.mockImplementation(
-        async ({ callbacks }: { callbacks: ConnectCallbacks }) => {
-          capturedDataCallback.current = callbacks.onData ?? null
-          return 'pty-id'
-        }
-      )
-      transportFactoryQueue.push(transport)
+    const pane = createPane(1)
+    const manager = createManager(1)
+    const deps = createDeps({
+      isVisibleRef: { current: false }
+    })
 
-      const pane = createPane(1)
-      const manager = createManager(1)
-      const deps = createDeps({
-        isVisibleRef: { current: false }
-      })
+    connectPanePty(pane as never, manager as never, deps as never)
+    await flushAsyncTicks(6)
 
-      connectPanePty(pane as never, manager as never, deps as never)
-      await flushAsyncTicks(6)
+    expect(capturedDataCallback.current).not.toBeNull()
+    const controlOutput = '\x1b[2J\x1b[Hhello\r\n'
+    capturedDataCallback.current?.(controlOutput, {
+      seq: controlOutput.length,
+      rawLength: controlOutput.length
+    })
+    expect(pane.terminal.write).not.toHaveBeenCalledWith(controlOutput, expect.any(Function))
 
-      expect(capturedDataCallback.current).not.toBeNull()
-      const controlOutput = '\x1b[2J\x1b[Hhello\r\n'
-      capturedDataCallback.current?.(controlOutput)
-      expect(pane.terminal.write).not.toHaveBeenCalledWith(controlOutput)
+    ;(deps.isVisibleRef as { current: boolean }).current = true
+    capturedDataCallback.current?.('visible\r\n', {
+      seq: controlOutput.length + 'visible\r\n'.length,
+      rawLength: 'visible\r\n'.length
+    })
+    await flushAsyncTicks(20)
 
-      for (const fn of pendingTimeouts) {
-        fn()
-      }
-
-      expect(pane.terminal.write).toHaveBeenCalledWith(controlOutput)
-    } finally {
-      globalThis.setTimeout = originalSetTimeout
-    }
+    expect(getMainBufferSnapshot).toHaveBeenCalledWith('pty-id', { scrollbackRows: 5000 })
+    expect(pane.terminal.write).toHaveBeenCalledWith(
+      expect.stringContaining('control snapshot'),
+      expect.any(Function)
+    )
   })
 
   it('keeps visually rich hidden PTY bytes on the live xterm path', async () => {
@@ -3023,15 +3031,26 @@ describe('connectPanePty', () => {
     }
   })
 
-  it('keeps split hidden synchronized output frames on the live xterm path', async () => {
+  it('restores safe split hidden synchronized output frames from the main snapshot', async () => {
     const { connectPanePty } = await import('./pty-connection')
     const transport = createMockTransport('pty-id')
-    const capturedDataCallback: { current: ((data: string) => void) | null } = { current: null }
+    const capturedDataCallback: {
+      current: ((data: string, meta?: { seq?: number; rawLength?: number }) => void) | null
+    } = { current: null }
     transport.connect.mockImplementation(async ({ callbacks }: { callbacks: ConnectCallbacks }) => {
       capturedDataCallback.current = callbacks.onData ?? null
       return 'pty-id'
     })
     transportFactoryQueue.push(transport)
+    const getMainBufferSnapshot = window.api.pty.getMainBufferSnapshot as unknown as ReturnType<
+      typeof vi.fn
+    >
+    getMainBufferSnapshot.mockResolvedValue({
+      data: 'snapshot table\r\nLONG_TABLE_SCROLL_RESTORE_marker\r\n',
+      cols: 100,
+      rows: 30,
+      seq: 80
+    })
 
     const pane = createPane(1)
     const manager = createManager(1)
@@ -3043,23 +3062,40 @@ describe('connectPanePty', () => {
     await flushAsyncTicks(6)
 
     expect(capturedDataCallback.current).not.toBeNull()
-    vi.useFakeTimers()
-    try {
-      const startChunk = '\x1b[?2026h'
-      const plainRowChunk = '| Sam Syntax | Compiler | Online |\r\n'
-      const endChunk = 'LONG_TABLE_SCROLL_RESTORE_marker\r\n\x1b[?2026l'
+    const startChunk = '\x1b[?2026h'
+    const plainRowChunk = '| Sam Syntax | Compiler | Online |\r\n'
+    const endChunk = 'LONG_TABLE_SCROLL_RESTORE_marker\r\n\x1b[?2026l'
+    const visibleChunk = 'visible-after-hidden\r\n'
 
-      capturedDataCallback.current?.(startChunk)
-      capturedDataCallback.current?.(plainRowChunk)
-      capturedDataCallback.current?.(endChunk)
+    capturedDataCallback.current?.(startChunk, {
+      seq: startChunk.length,
+      rawLength: startChunk.length
+    })
+    capturedDataCallback.current?.(plainRowChunk, {
+      seq: startChunk.length + plainRowChunk.length,
+      rawLength: plainRowChunk.length
+    })
+    capturedDataCallback.current?.(endChunk, {
+      seq: startChunk.length + plainRowChunk.length + endChunk.length,
+      rawLength: endChunk.length
+    })
 
-      expect(pane.terminal.write).not.toHaveBeenCalledWith(plainRowChunk)
-      vi.advanceTimersByTime(50)
-      expect(pane.terminal.write).toHaveBeenCalledWith(`${startChunk}${plainRowChunk}${endChunk}`)
-      expect(window.api.pty.getMainBufferSnapshot).not.toHaveBeenCalled()
-    } finally {
-      vi.useRealTimers()
-    }
+    expect(pane.terminal.write).not.toHaveBeenCalledWith(startChunk, expect.any(Function))
+    expect(pane.terminal.write).not.toHaveBeenCalledWith(plainRowChunk, expect.any(Function))
+    expect(pane.terminal.write).not.toHaveBeenCalledWith(endChunk, expect.any(Function))
+
+    ;(deps.isVisibleRef as { current: boolean }).current = true
+    capturedDataCallback.current?.(visibleChunk, {
+      seq: startChunk.length + plainRowChunk.length + endChunk.length + visibleChunk.length,
+      rawLength: visibleChunk.length
+    })
+    await flushAsyncTicks(20)
+
+    expect(getMainBufferSnapshot).toHaveBeenCalledWith('pty-id', { scrollbackRows: 5000 })
+    expect(pane.terminal.write).toHaveBeenCalledWith(
+      expect.stringContaining('snapshot table'),
+      expect.any(Function)
+    )
   })
 
   it('queues visible split-pane PTY bytes when the pane is not active', async () => {

tests/e2e/artificial-opencode-hidden-pressure-scenario.ts

@@ -171,7 +171,11 @@ export async function runHiddenRealPtyPressureScenario<
       ackGate
     )
 
-    if (pressureOutputMode === 'plain' || pressureOutputMode === 'title') {
+    if (
+      pressureOutputMode === 'plain' ||
+      pressureOutputMode === 'title' ||
+      pressureOutputMode === 'tui'
+    ) {
       expect(debug?.hiddenRendererSkipCount ?? 0).toBeGreaterThan(0)
       expect(debug?.hiddenRendererSkippedChars ?? 0).toBeGreaterThan(0)
     } else {