From c9e620bd2b6a241a2a38eefa0733c6a72dc5aab1 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Fri, 10 Jul 2026 23:23:01 -0700
Subject: [PATCH] fix(terminal): exclude passive mobile query responders

---
 docs/reference/terminal-query-authority.md    | 10 +++++-----
 src/main/runtime/mobile-presence-lock.test.ts | 16 ++++++++++++++++
 src/main/runtime/orca-runtime.ts              |  6 +++++-
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/docs/reference/terminal-query-authority.md b/docs/reference/terminal-query-authority.md
index 90e8511f106..ad712998820 100644
--- a/docs/reference/terminal-query-authority.md
+++ b/docs/reference/terminal-query-authority.md
@@ -104,11 +104,11 @@ arrived while the initial snapshot was being built and its output sequence is
 covered by that snapshot, runtime RPC re-emits only the bounded query sequence
 after the snapshot; ordinary covered output stays deduplicated. `terminal.send`
 accepts the resulting `inputKind: query-reply` only from the earliest active
-mobile subscriber while mobile owns the terminal driver. Earliest is determined
-by preserved `subscribedAt`, so a soft-leave resubscribe does not change reply
-ownership. Peer phones are rejected, the next subscriber is promoted on
-unsubscribe, and desktop parser and capability handlers stay silent until
-desktop retakes the driver.
+phone-fitted mobile subscriber while mobile owns the terminal driver. Earliest
+is determined by preserved `subscribedAt`, so a soft-leave resubscribe does not
+change reply ownership; passive desktop-mode watchers are excluded. Peer phones
+are rejected, the next subscriber is promoted on unsubscribe, and desktop
+parser and capability handlers stay silent until desktop retakes the driver.
 
 Everything the emulator emits outside a forwarding window is discarded, which
 also swallows unsolicited core emissions (e.g. native 997 color-scheme pushes
diff --git a/src/main/runtime/mobile-presence-lock.test.ts b/src/main/runtime/mobile-presence-lock.test.ts
index 015823f3a98..6213765bb20 100644
--- a/src/main/runtime/mobile-presence-lock.test.ts
+++ b/src/main/runtime/mobile-presence-lock.test.ts
@@ -271,6 +271,22 @@ describe('mobile presence lock — multi-mobile semantics', () => {
     expect(runtime.isMobileTerminalQueryReplyAuthority('pty-1', 'phone-B')).toBe(false)
   })
 
+  it('excludes an older passive desktop-mode subscriber from reply authority', async () => {
+    const { runtime } = createRuntime()
+    runtime.setMobileDisplayMode('pty-1', 'desktop')
+    await runtime.handleMobileSubscribe('pty-1', 'phone-A', { cols: 45, rows: 20 })
+    await vi.advanceTimersByTimeAsync(10)
+    await runtime.handleMobileSubscribe('pty-1', 'phone-B', { cols: 38, rows: 18 })
+
+    await vi.advanceTimersByTimeAsync(10)
+    runtime.markMobileActor('pty-1', 'phone-B')
+    runtime.setMobileDisplayMode('pty-1', 'auto')
+    await runtime.applyMobileDisplayMode('pty-1')
+
+    expect(runtime.isMobileTerminalQueryReplyAuthority('pty-1', 'phone-A')).toBe(false)
+    expect(runtime.isMobileTerminalQueryReplyAuthority('pty-1', 'phone-B')).toBe(true)
+  })
+
   it('most-recent actor wins active phone-fit dims (B subscribes after A)', async () => {
     const { runtime, ptySizes } = createRuntime()
     await runtime.handleMobileSubscribe('pty-1', 'phone-A', { cols: 45, rows: 20 })
diff --git a/src/main/runtime/orca-runtime.ts b/src/main/runtime/orca-runtime.ts
index 2a206acf32b..a4e3e64a272 100644
--- a/src/main/runtime/orca-runtime.ts
+++ b/src/main/runtime/orca-runtime.ts
@@ -6487,9 +6487,13 @@ export class OrcaRuntimeService {
       return false
     }
     // Why: soft-leave resubscribe preserves the original subscription time but
-    // reinserts the record. Elect from that stable age, not mutable Map order.
+    // reinserts the record. Elect fitted responders from that stable age, not
+    // mutable Map order or passive desktop-mode watchers.
     let earliest: { clientId: string; subscribedAt: number } | null = null
     for (const subscriber of subscribers.values()) {
+      if (!subscriber.wasResizedToPhone) {
+        continue
+      }
       if (earliest === null || subscriber.subscribedAt < earliest.subscribedAt) {
         earliest = subscriber
       }