Provide a stable URI for getting raw paste content

Summary: Fixes T9312. This is a bit fluff, but does simplify the view controller slightly and seems reasonable/useful in general.

Test Plan: Clicked "View Raw File" on a paste, got redirected to the raw file via a stable URI.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9312

Differential Revision: https://secure.phabricator.com/D14167

src/__phutil_library_map__.php

···
     'PhabricatorPasteListController' => 'applications/paste/controller/PhabricatorPasteListController.php',
     'PhabricatorPastePastePHIDType' => 'applications/paste/phid/PhabricatorPastePastePHIDType.php',
     'PhabricatorPasteQuery' => 'applications/paste/query/PhabricatorPasteQuery.php',
+    'PhabricatorPasteRawController' => 'applications/paste/controller/PhabricatorPasteRawController.php',
     'PhabricatorPasteRemarkupRule' => 'applications/paste/remarkup/PhabricatorPasteRemarkupRule.php',
     'PhabricatorPasteSchemaSpec' => 'applications/paste/storage/PhabricatorPasteSchemaSpec.php',
     'PhabricatorPasteSearchEngine' => 'applications/paste/query/PhabricatorPasteSearchEngine.php',
···
     'PhabricatorPasteListController' => 'PhabricatorPasteController',
     'PhabricatorPastePastePHIDType' => 'PhabricatorPHIDType',
     'PhabricatorPasteQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'PhabricatorPasteRawController' => 'PhabricatorPasteController',
     'PhabricatorPasteRemarkupRule' => 'PhabricatorObjectRemarkupRule',
     'PhabricatorPasteSchemaSpec' => 'PhabricatorConfigSchemaSpec',
     'PhabricatorPasteSearchEngine' => 'PhabricatorApplicationSearchEngine',

src/applications/paste/application/PhabricatorPasteApplication.php

···
         '(query/(?P<queryKey>[^/]+)/)?' => 'PhabricatorPasteListController',
         'create/' => 'PhabricatorPasteEditController',
         'edit/(?P<id>[1-9]\d*)/' => 'PhabricatorPasteEditController',
+        'raw/(?P<id>[1-9]\d*)/' => 'PhabricatorPasteRawController',
         'comment/(?P<id>[1-9]\d*)/' => 'PhabricatorPasteCommentController',
       ),
     );

src/applications/paste/controller/PhabricatorPasteRawController.php

···
+<?php
+
+/**
+ * Redirect to the current raw contents of a Paste.
+ *
+ * This controller provides a stable URI for getting the current contents of
+ * a paste, and slightly simplifies the view controller.
+ */
+final class PhabricatorPasteRawController
+  extends PhabricatorPasteController {
+
+  public function shouldAllowPublic() {
+    return true;
+  }
+
+  public function handleRequest(AphrontRequest $request) {
+    $viewer = $request->getViewer();
+    $id = $request->getURIData('id');
+
+    $paste = id(new PhabricatorPasteQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($id))
+      ->executeOne();
+    if (!$paste) {
+      return new Aphront404Response();
+    }
+
+    $file = id(new PhabricatorFileQuery())
+      ->setViewer($viewer)
+      ->withPHIDs(array($paste->getFilePHID()))
+      ->executeOne();
+    if (!$file) {
+      return new Aphront400Response();
+    }
+
+    return $file->getRedirectResponse();
+  }
+
+}

src/applications/paste/controller/PhabricatorPasteViewController.php

···
       return new Aphront404Response();
     }
 
-    $file = id(new PhabricatorFileQuery())
-      ->setViewer($viewer)
-      ->withPHIDs(array($paste->getFilePHID()))
-      ->executeOne();
-    if (!$file) {
-      return new Aphront400Response();
-    }
-
     $forks = id(new PhabricatorPasteQuery())
       ->setViewer($viewer)
       ->withParentPHIDs(array($paste->getPHID()))
···
     $fork_phids = mpull($forks, 'getPHID');
 
     $header = $this->buildHeaderView($paste);
-    $actions = $this->buildActionView($viewer, $paste, $file);
+    $actions = $this->buildActionView($viewer, $paste);
     $properties = $this->buildPropertyView($paste, $fork_phids, $actions);
 
     $object_box = id(new PHUIObjectBoxView())
···
 
   private function buildActionView(
     PhabricatorUser $viewer,
-    PhabricatorPaste $paste,
-    PhabricatorFile $file) {
+    PhabricatorPaste $paste) {
 
     $can_edit = PhabricatorPolicyFilter::hasCapability(
       $viewer,
···
       PhabricatorPolicyCapability::CAN_EDIT);
 
     $can_fork = $viewer->isLoggedIn();
-    $fork_uri = $this->getApplicationURI('/create/?parent='.$paste->getID());
+    $id = $paste->getID();
+    $fork_uri = $this->getApplicationURI('/create/?parent='.$id);
 
     return id(new PhabricatorActionListView())
       ->setUser($viewer)
···
           ->setIcon('fa-pencil')
           ->setDisabled(!$can_edit)
           ->setWorkflow(!$can_edit)
-          ->setHref($this->getApplicationURI('/edit/'.$paste->getID().'/')))
+          ->setHref($this->getApplicationURI("edit/{$id}/")))
       ->addAction(
         id(new PhabricatorActionView())
           ->setName(pht('Fork This Paste'))
···
         id(new PhabricatorActionView())
           ->setName(pht('View Raw File'))
           ->setIcon('fa-file-text-o')
-          ->setHref($file->getBestURI()));
+          ->setHref($this->getApplicationURI("raw/{$id}/")));
   }
 
   private function buildPropertyView(