From 3decc031222a54d850fb2ead53c5ece0c4408680 Mon Sep 17 00:00:00 2001
From: Neil <neil@stably.ai>
Date: Mon, 14 Sep 2026 14:57:10 -0700
Subject: [PATCH] fix(ai-vault): resolve lazy child resumes in their own
 workspace

---
 .../components/right-sidebar/AiVaultPanel.tsx |  7 +--
 .../right-sidebar/ai-vault-session-resume.ts  | 27 +++++++++
 .../ai-vault-session-worktree-map.test.tsx    | 55 +++++++++++++++++++
 3 files changed, 85 insertions(+), 4 deletions(-)

diff --git a/src/renderer/src/components/right-sidebar/AiVaultPanel.tsx b/src/renderer/src/components/right-sidebar/AiVaultPanel.tsx
index 0e0fe1d7a78..a24ce03b448 100644
--- a/src/renderer/src/components/right-sidebar/AiVaultPanel.tsx
+++ b/src/renderer/src/components/right-sidebar/AiVaultPanel.tsx
@@ -27,7 +27,7 @@ import {
 } from './ai-vault-session-projects'
 import {
   resolveAiVaultSessionResumeActions,
-  resolveAiVaultSessionResumeState
+  resolveAiVaultHistorySessionResumeState
 } from './ai-vault-session-resume'
 import { useAiVaultSessionLaunchActions } from './ai-vault-session-launch-actions'
 import type { AiVaultResumeInChatEligibility } from './ai-vault-session-resume-in-chat'
@@ -263,9 +263,8 @@ export default function AiVaultPanel(): React.JSX.Element {
 
   const getSessionResumeState = useCallback(
     (session: AiVaultSession) =>
-      resolveAiVaultSessionResumeState({
-        sessionFilePath: session.filePath,
-        sessionExecutionHostId: session.executionHostId,
+      resolveAiVaultHistorySessionResumeState({
+        session,
         worktreeInfo: getSessionWorktreeInfo(session),
         activeWorktreeId: effectiveActiveWorktreeId,
         worktrees: allWorktrees,
diff --git a/src/renderer/src/components/right-sidebar/ai-vault-session-resume.ts b/src/renderer/src/components/right-sidebar/ai-vault-session-resume.ts
index d021fc66b1f..1150f1ef2d6 100644
--- a/src/renderer/src/components/right-sidebar/ai-vault-session-resume.ts
+++ b/src/renderer/src/components/right-sidebar/ai-vault-session-resume.ts
@@ -15,6 +15,7 @@ import { translate } from '@/i18n/i18n'
 import { parseWorkspaceKey } from '../../../../shared/workspace-scope'
 import {
   canJumpToAiVaultSessionWorktree,
+  resolveAiVaultSessionWorktreeInfo,
   type AiVaultSessionWorktreeInfo
 } from './ai-vault-session-worktree'
 
@@ -85,6 +86,32 @@ export function resolveAiVaultSessionResumeState(args: {
   }
 }
 
+export function resolveAiVaultHistorySessionResumeState(
+  args: Omit<
+    Parameters<typeof resolveAiVaultSessionResumeState>[0],
+    'sessionFilePath' | 'sessionExecutionHostId'
+  > & {
+    session: AiVaultSession
+  }
+): AiVaultSessionResumeState {
+  const child = Boolean(args.session.subagent)
+  return resolveAiVaultSessionResumeState({
+    ...args,
+    sessionFilePath: args.session.filePath,
+    sessionExecutionHostId: args.session.executionHostId,
+    worktreeInfo: child
+      ? resolveAiVaultSessionWorktreeInfo({
+          session: args.session,
+          worktrees: args.worktrees,
+          repos: args.repos,
+          activeWorktreeId: args.activeWorktreeId
+        })
+      : args.worktreeInfo,
+    // Lazy children are absent from the panel map; never resume them in an unrelated active workspace.
+    activeWorktreeId: child ? null : args.activeWorktreeId
+  })
+}
+
 export function resolveAiVaultSessionResumeActions(args: {
   sessionFilePath: string | null
   sessionExecutionHostId?: AiVaultSession['executionHostId'] | null
diff --git a/src/renderer/src/components/right-sidebar/ai-vault-session-worktree-map.test.tsx b/src/renderer/src/components/right-sidebar/ai-vault-session-worktree-map.test.tsx
index cc71cc9b55a..d54c2777841 100644
--- a/src/renderer/src/components/right-sidebar/ai-vault-session-worktree-map.test.tsx
+++ b/src/renderer/src/components/right-sidebar/ai-vault-session-worktree-map.test.tsx
@@ -235,3 +235,58 @@ describe('useAiVaultSessionWorktreeMap', () => {
     expect(elapsedMs).toBeLessThan(150)
   })
 })
+
+import { resolveAiVaultHistorySessionResumeState } from './ai-vault-session-resume'
+
+describe('lazy OMP child resume targets', () => {
+  it.each([worktreeA.id, worktreeB.id, null])(
+    'keeps child and grandchild in their own worktree with active %s',
+    (activeWorktreeId) => {
+      const parent = makeSession({ agent: 'omp', id: 'omp:parent', cwd: worktreeA.path })
+      const { result } = renderHook(() =>
+        useAiVaultSessionWorktreeMap({ sessions: [parent], repos, worktrees })
+      )
+      for (const id of ['child', 'grandchild']) {
+        const session = makeSession({
+          agent: 'omp',
+          id,
+          cwd: worktreeA.path,
+          subagent: { parentSessionId: parent.sessionId, agentType: null, status: null }
+        })
+        expect(result.current.has(id)).toBe(false)
+        const target = resolveAiVaultHistorySessionResumeState({
+          session,
+          worktreeInfo: result.current.get(id) ?? null,
+          activeWorktreeId,
+          worktrees,
+          repos
+        })
+        expect(target).toEqual({
+          blocked: false,
+          worktreeId: worktreeA.id,
+          usesSessionWorktree: true
+        })
+      }
+    }
+  )
+  it.each([{ cwd: null }, { cwd: '/missing' }, { executionHostId: 'ssh:other' as const }])(
+    'refuses unmatched child %j instead of active-workspace fallback',
+    (overrides) => {
+      const session = makeSession({
+        agent: 'omp',
+        cwd: worktreeA.path,
+        subagent: { parentSessionId: 'parent', agentType: null, status: null },
+        ...overrides
+      })
+      expect(
+        resolveAiVaultHistorySessionResumeState({
+          session,
+          worktreeInfo: null,
+          activeWorktreeId: worktreeB.id,
+          worktrees,
+          repos
+        })
+      ).toEqual({ blocked: true, worktreeId: null, usesSessionWorktree: false })
+    }
+  )
+})