fix: guard hidden hydration against transport replacement (#2686)

src/renderer/src/components/terminal-pane/use-terminal-pane-global-effects.test.ts

@@ -388,6 +388,77 @@ describe('useTerminalPaneGlobalEffects', () => {
     expect(terminal.write).toHaveBeenCalledWith('new-output', expect.any(Function))
   })
 
+  it('does not replay stale hydration after the pane transport is replaced', async () => {
+    const terminal = {
+      name: 'terminal-a',
+      options: { scrollback: 1000 },
+      write: vi.fn((_data: string, callback?: () => void) => callback?.())
+    }
+    const pane = { id: 1, terminal }
+    const oldTransport = { getPtyId: vi.fn(() => 'pty-1') }
+    const newTransport = { getPtyId: vi.fn(() => 'pty-2') }
+    const paneTransports = new Map<number, typeof oldTransport | typeof newTransport>([
+      [1, oldTransport]
+    ])
+    const manager = {
+      getPanes: vi.fn(() => [pane]),
+      resumeRendering: vi.fn(),
+      suspendRendering: vi.fn(),
+      fitAllPanes: vi.fn(),
+      getActivePane: vi.fn(() => null),
+      setActivePane: vi.fn()
+    }
+    let resolveSnapshot!: (snapshot: { data: string; cols: number; rows: number } | null) => void
+    const snapshotPromise = new Promise<{ data: string; cols: number; rows: number } | null>(
+      (resolve) => {
+        resolveSnapshot = resolve
+      }
+    )
+    window.api.pty.serializeHeadlessBuffer = vi.fn((id: string) => {
+      if (id === 'pty-1') {
+        return snapshotPromise
+      }
+      return Promise.resolve(null)
+    }) as typeof window.api.pty.serializeHeadlessBuffer
+    const baseArgs = {
+      tabId: 'tab-1',
+      worktreeId: 'wt-1',
+      isActive: true,
+      isVisible: true,
+      paneCount: 1,
+      managerRef: { current: manager as never },
+      containerRef: { current: null },
+      paneTransportsRef: { current: paneTransports as never },
+      replayingPanesRef: { current: new Map<number, number>() },
+      isActiveRef: { current: false },
+      isVisibleRef: { current: false },
+      toggleExpandPane: vi.fn()
+    }
+    queueHiddenTerminalOutput(terminal, 'pty-1', 'old-output')
+
+    beginHookRender()
+    useTerminalPaneGlobalEffects(baseArgs)
+
+    paneTransports.set(1, newTransport)
+    queueHiddenTerminalOutput(terminal, 'pty-2', 'new-output')
+    resolveSnapshot({ data: 'stale-headless-output', cols: 120, rows: 40 })
+    await Promise.resolve()
+    await Promise.resolve()
+
+    expect(terminal.write).not.toHaveBeenCalledWith('stale-headless-output', expect.any(Function))
+    terminal.write.mockClear()
+
+    beginHookRender()
+    useTerminalPaneGlobalEffects(baseArgs)
+    await Promise.resolve()
+    await Promise.resolve()
+
+    expect(window.api.pty.serializeHeadlessBuffer).toHaveBeenCalledWith('pty-2', {
+      scrollbackRows: 1000
+    })
+    expect(terminal.write).toHaveBeenCalledWith('new-output', expect.any(Function))
+  })
+
   it('restores from the pre-hide scroll state when hidden layout changes the viewport', () => {
     const terminalA = { name: 'terminal-a' }
     const manager = {

src/renderer/src/components/terminal-pane/use-terminal-pane-global-effects.ts

@@ -88,8 +88,16 @@ export function useTerminalPaneGlobalEffects({
       if (!hydration) {
         return
       }
-      const transport = paneTransportsRef.current.get(pane.id)
-      if (transport?.getPtyId() !== hydration.ptyId) {
+      const getCurrentPtyId = (): string | null => {
+        const currentPane = managerRef.current
+          ?.getPanes()
+          .find((candidate) => candidate.id === pane.id)
+        if (currentPane?.terminal !== pane.terminal) {
+          return null
+        }
+        return paneTransportsRef.current.get(pane.id)?.getPtyId() ?? null
+      }
+      if (getCurrentPtyId() !== hydration.ptyId) {
         clearHiddenTerminalOutputForPty(pane.terminal, hydration.ptyId)
         return
       }
@@ -104,7 +112,7 @@ export function useTerminalPaneGlobalEffects({
             cancelHiddenTerminalHydration(pane.terminal, hydration)
             return
           }
-          if (transport.getPtyId() !== hydration.ptyId) {
+          if (getCurrentPtyId() !== hydration.ptyId) {
             clearHiddenTerminalOutputForPty(pane.terminal, hydration.ptyId)
             return
           }
@@ -138,7 +146,7 @@ export function useTerminalPaneGlobalEffects({
             cancelHiddenTerminalHydration(pane.terminal, hydration)
             return
           }
-          if (transport.getPtyId() !== hydration.ptyId) {
+          if (getCurrentPtyId() !== hydration.ptyId) {
             clearHiddenTerminalOutputForPty(pane.terminal, hydration.ptyId)
             return
           }
@@ -156,7 +164,7 @@ export function useTerminalPaneGlobalEffects({
           markHiddenTerminalFallbackReplayed(pane.terminal, hydration)
         })
     },
-    [isVisibleRef, paneTransportsRef, replayingPanesRef]
+    [isVisibleRef, managerRef, paneTransportsRef, replayingPanesRef]
   )
 
   useEffect(() => {