Slightly modernize all Diffusion edit endpoints

Summary: Ref T4245. Prepares edit endpoints for more flexible repository identifiers.

Test Plan:
  - Added, edited, deleted mirror.
  - Created repository.
  - Edited basic repository information.
  - Edited policies for a repository.
  - Activated/deactivated repository.
  - Updated a repository.
  - Hit "Delete" dialog for a repository.
  - Edited hosting.
  - Toggled dangerous changes.
  - Edited branches.
  - Edited automation.
  - Tested automation.
  - Edited storage.
  - Edited staging.
  - Edited encoding.
  - Edited symbols.
  - Edited branches.
  - Edited actions.
  - Tried to do edits as an unprivileged user.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T4245

Differential Revision: https://secure.phabricator.com/D14945

src/applications/diffusion/controller/DiffusionRepositoryDefaultController.php

@@ -2,7 +2,12 @@
 
 final class DiffusionRepositoryDefaultController extends DiffusionController {
 
-  protected function processDiffusionRequest(AphrontRequest $request) {
+  public function handleRequest(AphrontRequest $request) {
+    $response = $this->loadDiffusionContext();
+    if ($response) {
+      return $response;
+    }
+
     // NOTE: This controller is just here to make sure we call
     // willBeginExecution() on any /diffusion/X/ URI, so we can intercept
     // `git`, `hg` and `svn` HTTP protocol requests.
@@ -11,7 +16,10 @@ final class DiffusionRepositoryDefaultController extends DiffusionController {
     // clone URI with "/anything.git" at the end into their web browser.
     // Send them to the canonical repository URI.
 
+    $drequest = $this->getDiffusionRequest();
+    $repository = $drequest->getRepository();
+
     return id(new AphrontRedirectResponse())
-      ->setURI($this->getDiffusionRequest()->getRepository()->getURI());
+      ->setURI($repository->getURI());
   }
 }