test(pty): pin terminal query-reply order; align one renderer call site (#16862)

* fix(pty): preserve renderer query reply ordering

* docs(pty): explain renderer query ordering

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

@@ -356,10 +356,12 @@ describe('connectPanePty', () => {
         await flushAsyncTicks(8)
 
         const replies = transport.sendInputImmediate.mock.calls.map((call) => String(call[0]))
-        expect(replies.some((reply) => reply.startsWith('\x1b]11;rgb:'))).toBe(true)
         // oxlint-disable-next-line no-control-regex -- the ESC byte IS the payload: this matches the CPR reply
-        expect(replies.some((reply) => /^\u001b\[\d+;\d+R$/.test(reply))).toBe(true)
-        expect(replies).toContain(DEFAULT_DA1_RESPONSE)
+        const cprReply = replies.find((reply) => /^\u001b\[\d+;\d+R$/.test(reply))
+        const oscReply = replies.find((reply) => reply.startsWith('\x1b]11;rgb:'))
+        expect(oscReply).toBeDefined()
+        expect(cprReply).toBeDefined()
+        expect(replies).toEqual([oscReply, cprReply, DEFAULT_DA1_RESPONSE])
         const written = writtenFloodData(pane)
         expect(written).not.toContain('aaaa')
         expect(written).not.toContain('bbbb')

src/renderer/src/components/terminal-pane/pty-connection/live-data-callback.ts

@@ -123,11 +123,7 @@ export function bindLiveDataCallback(session: ConnectPanePtySession): void {
       session.schedulePendingStartupCommandDelivery()
       return
     }
-    if (pendingForegroundQuery?.statelessQueryData) {
-      session.writePtyOutputToXterm(pendingForegroundQuery.statelessQueryData, true, {
-        hiddenStartupRendererQuery: true
-      })
-    }
+    // Keep source order aligned with sibling producers; xterm's async write buffer made the old inversion latent.
     if (pendingForegroundQuery?.oscColorQueryData) {
       sendTerminalOscColorQueryReplies(
         pendingForegroundQuery.oscColorQueryData,
@@ -136,6 +132,11 @@ export function bindLiveDataCallback(session: ConnectPanePtySession): void {
         session.sendDesktopQueryReplyImmediate
       )
     }
+    if (pendingForegroundQuery?.statelessQueryData) {
+      session.writePtyOutputToXterm(pendingForegroundQuery.statelessQueryData, true, {
+        hiddenStartupRendererQuery: true
+      })
+    }
     const restoreAppliesToCurrentPty =
       session.hiddenOutputRestorePtyId !== null &&
       session.transport.getPtyId() === session.hiddenOutputRestorePtyId

src/renderer/src/components/terminal-pane/terminal-capability-replies.test.ts

@@ -88,6 +88,34 @@ describe('installTerminalCapabilityReplyHandlers', () => {
     }
   })
 
+  it.each([
+    ['OSC 11 then CPR', '\x1b]11;?\x1b\\\x1b[6n', ['osc', 'cpr']],
+    ['CPR then OSC 11', '\x1b[6n\x1b]11;?\x1b\\', ['cpr', 'osc']]
+  ] as const)('preserves combined query order (%s)', async (_name, input, expectedKinds) => {
+    const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true })
+    term.options.theme = { background: '#ffffff' }
+    const replies: string[] = []
+    const disposable = installTerminalCapabilityReplyHandlers({
+      terminal: term as never,
+      parser: term.parser,
+      sendInput: (data) => {
+        replies.push(data)
+      },
+      isReplaying: () => false
+    })
+    const onData = term.onData((data) => replies.push(data))
+
+    try {
+      await writeTerminal(term, input)
+      const kinds = replies.map((reply) => (reply.startsWith('\x1b]11;') ? 'osc' : 'cpr'))
+      expect(kinds).toEqual(expectedKinds)
+    } finally {
+      onData.dispose()
+      disposable.dispose()
+      term.dispose()
+    }
+  })
+
   it('answers OSC color queries for active rgba and modern rgb theme colors', async () => {
     const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true })
     term.options.theme = {

src/shared/terminal-query-reply.test.ts

@@ -176,6 +176,25 @@ describe('query reply ordering (termenv OSC-then-CPR)', () => {
     vi.useRealTimers()
   })
 
+  it('preserves reverse query order when CPR arrives before the color query', async () => {
+    vi.useFakeTimers()
+    const pty: string[] = []
+    const ingress = new PtyStartupIngress({
+      ownerBackend: 'posix-pty',
+      write: (data) => pty.push(data),
+      onEmission: () => {}
+    })
+    const write = hostWrites(ingress, pty)
+
+    write(CPR_REPLY)
+    write(OSC_11_REPLY)
+    await vi.advanceTimersByTimeAsync(200)
+
+    expect(pty).toEqual([CPR_REPLY, OSC_11_REPLY])
+    ingress.drainAndClose()
+    vi.useRealTimers()
+  })
+
   it('keeps a CPR immediate when no color reply is deferred', () => {
     vi.useFakeTimers()
     const pty: string[] = []