fix(fs): stop listing issuer homes at the filesystem root

src/backend/controllers/fs/FSController.ts

@@ -1110,7 +1110,6 @@ export class FSController extends PuterController {
             const rootChildren = await listRootEntries(
                 actor,
                 this.stores.fsEntry,
-                this.services.permission,
             );
             const rootSuggestions =
                 await this.services.suggestedApps.getSuggestedAppsForEntries(

src/backend/controllers/fs/LegacyFSController.ts

@@ -484,7 +484,6 @@ export class LegacyFSController extends PuterController {
             const rootChildren = await listRootEntries(
                 actor,
                 this.stores.fsEntry,
-                this.services.permission,
             );
             const rootSuggestions =
                 await this.services.suggestedApps.getSuggestedAppsForEntries(

src/backend/services/fs/rootListing.test.ts

@@ -66,8 +66,7 @@ const makeUser = async () => {
     return { userId: created.id, username, actor };
 };
 
-const listFor = (actor: Actor) =>
-    listRootEntries(actor, fsEntryStore, permissionService);
+const listFor = (actor: Actor) => listRootEntries(actor, fsEntryStore);
 
 describe('listRootEntries', () => {
     it('shows the actor their own home directory, exactly once', async () => {
@@ -91,7 +90,7 @@ describe('listRootEntries', () => {
         );
     });
 
-    it('adds the home of every user who has granted the actor a permission', async () => {
+    it('leaves an issuer’s home out of root when only a file was shared', async () => {
         const holder = await makeUser();
         const issuer = await makeUser();
         const shared = (await fsEntryStore.getEntryByPath(
@@ -105,9 +104,11 @@ describe('listRootEntries', () => {
 
         const entries = await listFor(holder.actor);
 
-        expect(entries.map((entry) => entry.path).sort()).toEqual(
-            [`/${holder.username}`, `/${issuer.username}`].sort(),
-        );
+        // Listing it here would advertise a folder readdir then refuses to
+        // open: the grant is on Documents, which says nothing about its parent.
+        expect(entries.map((entry) => entry.path)).toEqual([
+            `/${holder.username}`,
+        ]);
     });
 
     it('heals a home row whose path drifted from the username', async () => {

src/backend/services/fs/rootListing.ts

@@ -20,19 +20,18 @@
 import type { Actor } from '../../core/actor.js';
 import type { FSEntry } from '../../stores/fs/FSEntry.js';
 import type { FSEntryStore } from '../../stores/fs/FSEntryStore.js';
-import type { PermissionService } from '../permission/PermissionService.js';
 
 /**
  * Synthesize the listing for the virtual root `/`. There is no fsentry row at
- * `/` — instead root is a virtual aggregate of user-directory entries the actor
- * can see: the actor's own home plus any other users' homes granted via
- * permission issuers (i.e. users that have shared something with this actor).
- * Mirrors v1's `LLListUsers`.
+ * `/` — root stands in for the actor's own home.
+ *
+ * Issuer homes are deliberately absent: a grant on a file says nothing about
+ * its ancestors, so listing them advertised folders `readdir` then refused to
+ * open. Shares are reached through the sharing API instead.
  */
 export async function listRootEntries(
     actor: Actor,
     fsEntryStore: FSEntryStore,
-    permissionService: PermissionService,
 ): Promise<FSEntry[]> {
     const entries: FSEntry[] = [];
     const seenPaths = new Set<string>();
@@ -69,15 +68,5 @@ export async function listRootEntries(
 
     await pushByUsername(actor.user.username);
 
-    if (typeof userId === 'number') {
-        const issuers = await permissionService.listUserPermissionIssuers({
-            id: userId,
-        });
-        for (const issuer of issuers) {
-            if (!issuer) continue;
-            await pushByUsername(issuer.username);
-        }
-    }
-
     return entries;
 }