fix(core): protect home descendants from FFF

packages/core/src/filesystem/protected.ts

@@ -7,6 +7,11 @@ export function isHome(directory: string) {
   return path.resolve(directory) === path.resolve(home)
 }
 
+export function containsHome(directory: string) {
+  const relative = path.relative(directory, home)
+  return relative === "" || (relative !== ".." && !relative.startsWith(`..${path.sep}`) && !path.isAbsolute(relative))
+}
+
 const DARWIN_HOME = [
   "Music",
   "Pictures",

packages/core/src/filesystem/search.ts

@@ -177,6 +177,10 @@ export const fffLayer = Layer.effect(
   }),
 )
 
+export function isPersistentEligible(location: Location.Interface) {
+  return !!location.vcs && !Protected.containsHome(location.project.directory)
+}
+
 export const layer = (options?: Options) =>
   Layer.unwrap(
     Effect.gen(function* () {
@@ -184,7 +188,7 @@ export const layer = (options?: Options) =>
         return ripgrepLayer
       const location = yield* Location.Service
       // Non-VCS locations can contain many repositories, so avoid eagerly content-indexing the entire aggregate tree.
-      return location.vcs && !Protected.isHome(location.directory) ? fffLayer : ripgrepLayer
+      return isPersistentEligible(location) ? fffLayer : ripgrepLayer
     }),
   )
 

packages/core/test/filesystem/search.test.ts

@@ -15,6 +15,27 @@ import { AbsolutePath, RelativePath } from "@opencode-ai/core/schema"
 import { location } from "../fixture/location"
 
 describe("FileSystemSearch", () => {
+  test("disables persistent indexing when the worktree contains home", () => {
+    const home = AbsolutePath.make(os.homedir())
+    const directory = AbsolutePath.make(path.join(home, "broad-location"))
+    const vcs = { type: "git" as const, store: AbsolutePath.make(path.join(home, ".git")) }
+    expect(FileSystemSearch.isPersistentEligible(location({ directory }, { projectDirectory: home, vcs }))).toBe(false)
+    expect(
+      FileSystemSearch.isPersistentEligible(
+        location({ directory }, { projectDirectory: AbsolutePath.make(path.dirname(home)), vcs }),
+      ),
+    ).toBe(false)
+  })
+
+  test("enables persistent indexing for a nested worktree below home", () => {
+    const directory = AbsolutePath.make(path.join(os.homedir(), "project"))
+    expect(
+      FileSystemSearch.isPersistentEligible(
+        location({ directory }, { vcs: { type: "git", store: AbsolutePath.make(path.join(directory, ".git")) } }),
+      ),
+    ).toBe(true)
+  })
+
   test("honors wildcard directory rules from .gitignore", async () => {
     const directory = await mkdtemp(path.join(os.tmpdir(), "opencode-fff-ignore-"))
     try {