Implement "Body" field in Herald pre-commit content hooks

Summary: Ref T4195. Adds support for writing rules against commit message bodies.

Test Plan: Pushed git, hg, svn commits and verified their bodies populated correctly in transcripts.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4195

Differential Revision: https://secure.phabricator.com/D7796

src/applications/diffusion/engine/DiffusionCommitHookEngine.php

@@ -934,4 +934,34 @@ final class DiffusionCommitHookEngine extends Phobject {
     return $diff->getChangesets();
   }
 
+  public function loadCommitRefForCommit($identifier) {
+    $repository = $this->getRepository();
+    $vcs = $repository->getVersionControlSystem();
+    switch ($vcs) {
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
+        return id(new DiffusionLowLevelGitCommitQuery())
+          ->setRepository($repository)
+          ->withIdentifier($identifier)
+          ->execute();
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
+        return id(new DiffusionLowLevelMercurialCommitQuery())
+          ->setRepository($repository)
+          ->withIdentifier($identifier)
+          ->execute();
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
+        // For subversion, we need to use `svnlook`.
+        list($message) = execx(
+          'svnlook log -t %s %s',
+          $this->subversionTransaction,
+          $this->subversionRepository);
+
+        return id(new DiffusionCommitRef())
+          ->setMessage($message);
+        break;
+      default:
+        throw new Exception(pht("Unknown VCS '%s!'", $vcs));
+    }
+  }
+
+
 }

src/applications/diffusion/herald/HeraldPreCommitContentAdapter.php

@@ -5,6 +5,7 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
   private $log;
   private $hookEngine;
   private $changesets;
+  private $commitRef;
 
   public function setPushLog(PhabricatorRepositoryPushLog $log) {
     $this->log = $log;
@@ -84,6 +85,8 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
   public function getHeraldField($field) {
     $log = $this->getObject();
     switch ($field) {
+      case self::FIELD_BODY:
+        return $this->getCommitRef()->getMessage();
       case self::FIELD_DIFF_FILE:
         return $this->getDiffContent('name');
       case self::FIELD_DIFF_CONTENT:
@@ -179,4 +182,12 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
     return $result;
   }
 
+  private function getCommitRef() {
+    if ($this->commitRef === null) {
+      $this->commitRef = $this->hookEngine->loadCommitRefForCommit(
+        $this->log->getRefNew());
+    }
+    return $this->commitRef;
+  }
+
 }

src/applications/herald/storage/HeraldRule.php

@@ -16,7 +16,7 @@ final class HeraldRule extends HeraldDAO
   protected $ruleType;
   protected $isDisabled = 0;
 
-  protected $configVersion = 18;
+  protected $configVersion = 19;
 
   // phids for which this rule has been applied
   private $ruleApplied = self::ATTACHABLE;