Add 'repositoryPHID' to 'differential.createrawdiff'

Summary:
See <https://github.com/facebook/phabricator/issues/596>

Broadly, Facebook would like to bring Pull Requests from GitHub into Phabricator.

In the long term we can do this properly via Doorkeeper/Nuance, but that's probably a ways off. This seems like a reasonable low-budget compromise for now.

I'm a little hesitant to add a ton of parameters to this call, but `repositoryPHID` seems pretty reasonable, and is notable because it also controls default policies.

Test Plan:
  - Created a diff with no repositoryPHID.
  - Created a diff with a repositoryPHID.
    - Verified it carried over when the diff was used to create a revision.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: ptarjan, jamesgpearce, epriestley

Differential Revision: https://secure.phabricator.com/D9023

src/applications/differential/conduit/ConduitAPI_differential_createrawdiff_Method.php

@@ -4,12 +4,13 @@ final class ConduitAPI_differential_createrawdiff_Method
   extends ConduitAPI_differential_Method {
 
   public function getMethodDescription() {
-    return "Create a new Differential diff from a raw diff source.";
+    return pht("Create a new Differential diff from a raw diff source.");
   }
 
   public function defineParamTypes() {
     return array(
       'diff' => 'required string',
+      'repositoryPHID' => 'optional string',
     );
   }
 
@@ -23,8 +24,23 @@ final class ConduitAPI_differential_createrawdiff_Method
   }
 
   protected function execute(ConduitAPIRequest $request) {
+    $viewer = $request->getUser();
     $raw_diff = $request->getValue('diff');
 
+    $repository_phid = $request->getValue('repositoryPHID');
+    if ($repository_phid) {
+      $repository = id(new PhabricatorRepositoryQuery())
+        ->setViewer($viewer)
+        ->withPHIDs(array($repository_phid))
+        ->executeOne();
+      if (!$repository) {
+        throw new Exception(
+          pht('No such repository "%s"!', $repository_phid));
+      }
+    } else {
+      $repository = null;
+    }
+
     $parser = new ArcanistDiffParser();
     $changes = $parser->parseDiff($raw_diff);
     $diff = DifferentialDiff::newFromRawChanges($changes);
@@ -32,8 +48,13 @@ final class ConduitAPI_differential_createrawdiff_Method
     $diff->setLintStatus(DifferentialLintStatus::LINT_SKIP);
     $diff->setUnitStatus(DifferentialUnitStatus::UNIT_SKIP);
 
-    $diff->setAuthorPHID($request->getUser()->getPHID());
+    $diff->setAuthorPHID($viewer->getPHID());
     $diff->setCreationMethod('web');
+
+    if ($repository) {
+      $diff->setRepositoryPHID($repository->getPHID());
+    }
+
     $diff->save();
 
     return $this->buildDiffInfoDictionary($diff);