Policy - lock down DiffusionSymbolQuery repo-loading code

Summary: Ref T7094.

Test Plan: couldn't really test this - how does one get symbols going nowadays given they are acanist project based?

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7094

Differential Revision: https://secure.phabricator.com/D11584

src/applications/diffusion/controller/DiffusionSymbolController.php

@@ -8,8 +8,9 @@ final class DiffusionSymbolController extends DiffusionController {
     $user = $request->getUser();
     $this->name = $request->getURIData('name');
 
-    $query = new DiffusionSymbolQuery();
-    $query->setName($this->name);
+    $query = id(new DiffusionSymbolQuery())
+      ->setViewer($user)
+      ->setName($this->name);
 
     if ($request->getStr('context') !== null) {
       $query->setContext($request->getStr('context'));