Index: src/__phutil_library_map__.php
===================================================================
--- src/__phutil_library_map__.php
+++ src/__phutil_library_map__.php
@@ -482,6 +482,7 @@
     'DiffusionCommitHookRejectException' => 'applications/diffusion/exception/DiffusionCommitHookRejectException.php',
     'DiffusionCommitParentsQuery' => 'applications/diffusion/query/parents/DiffusionCommitParentsQuery.php',
     'DiffusionCommitQuery' => 'applications/diffusion/query/DiffusionCommitQuery.php',
+    'DiffusionCommitRef' => 'applications/diffusion/data/DiffusionCommitRef.php',
     'DiffusionCommitTagsController' => 'applications/diffusion/controller/DiffusionCommitTagsController.php',
     'DiffusionController' => 'applications/diffusion/controller/DiffusionController.php',
     'DiffusionDiffController' => 'applications/diffusion/controller/DiffusionDiffController.php',
@@ -506,6 +507,7 @@
     'DiffusionLintController' => 'applications/diffusion/controller/DiffusionLintController.php',
     'DiffusionLintDetailsController' => 'applications/diffusion/controller/DiffusionLintDetailsController.php',
     'DiffusionLintSaveRunner' => 'applications/diffusion/DiffusionLintSaveRunner.php',
+    'DiffusionLowLevelGitCommitQuery' => 'applications/diffusion/query/lowlevel/DiffusionLowLevelGitCommitQuery.php',
     'DiffusionLowLevelGitRefQuery' => 'applications/diffusion/query/lowlevel/DiffusionLowLevelGitRefQuery.php',
     'DiffusionLowLevelMercurialBranchesQuery' => 'applications/diffusion/query/lowlevel/DiffusionLowLevelMercurialBranchesQuery.php',
     'DiffusionLowLevelQuery' => 'applications/diffusion/query/lowlevel/DiffusionLowLevelQuery.php',
@@ -2866,6 +2868,7 @@
     'DiffusionCommitHookRejectException' => 'Exception',
     'DiffusionCommitParentsQuery' => 'DiffusionQuery',
     'DiffusionCommitQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'DiffusionCommitRef' => 'Phobject',
     'DiffusionCommitTagsController' => 'DiffusionController',
     'DiffusionController' => 'PhabricatorController',
     'DiffusionDiffController' => 'DiffusionController',
@@ -2887,6 +2890,7 @@
     'DiffusionLastModifiedController' => 'DiffusionController',
     'DiffusionLintController' => 'DiffusionController',
     'DiffusionLintDetailsController' => 'DiffusionController',
+    'DiffusionLowLevelGitCommitQuery' => 'DiffusionLowLevelQuery',
     'DiffusionLowLevelGitRefQuery' => 'DiffusionLowLevelQuery',
     'DiffusionLowLevelMercurialBranchesQuery' => 'DiffusionLowLevelQuery',
     'DiffusionLowLevelQuery' => 'Phobject',
Index: src/applications/diffusion/data/DiffusionCommitRef.php
===================================================================
--- /dev/null
+++ src/applications/diffusion/data/DiffusionCommitRef.php
@@ -0,0 +1,59 @@
+<?php
+
+final class DiffusionCommitRef extends Phobject {
+
+  private $message;
+  private $authorName;
+  private $authorEmail;
+  private $committerName;
+  private $committerEmail;
+
+  public function setCommitterEmail($committer_email) {
+    $this->committerEmail = $committer_email;
+    return $this;
+  }
+
+  public function getCommitterEmail() {
+    return $this->committerEmail;
+  }
+
+
+  public function setCommitterName($committer_name) {
+    $this->committerName = $committer_name;
+    return $this;
+  }
+
+  public function getCommitterName() {
+    return $this->committerName;
+  }
+
+
+  public function setAuthorEmail($author_email) {
+    $this->authorEmail = $author_email;
+    return $this;
+  }
+
+  public function getAuthorEmail() {
+    return $this->authorEmail;
+  }
+
+
+  public function setAuthorName($author_name) {
+    $this->authorName = $author_name;
+    return $this;
+  }
+
+  public function getAuthorName() {
+    return $this->authorName;
+  }
+
+  public function setMessage($message) {
+    $this->message = $message;
+    return $this;
+  }
+
+  public function getMessage() {
+    return $this->message;
+  }
+
+}
Index: src/applications/diffusion/query/lowlevel/DiffusionLowLevelGitCommitQuery.php
===================================================================
--- /dev/null
+++ src/applications/diffusion/query/lowlevel/DiffusionLowLevelGitCommitQuery.php
@@ -0,0 +1,48 @@
+<?php
+
+final class DiffusionLowLevelGitCommitQuery extends DiffusionLowLevelQuery {
+
+  private $identifier;
+
+  public function withIdentifier($identifier) {
+    $this->identifier = $identifier;
+    return $this;
+  }
+
+  protected function executeQuery() {
+    $repository = $this->getRepository();
+
+    // NOTE: %B was introduced somewhat recently in git's history, so pull
+    // commit message information with %s and %b instead.
+
+    // Even though we pass --encoding here, git doesn't always succeed, so
+    // we try a little harder, since git *does* tell us what the actual encoding
+    // is correctly (unless it doesn't; encoding is sometimes empty).
+    list($info) = $repository->execxLocalCommand(
+      'log -n 1 --encoding=%s --format=%s %s --',
+      'UTF-8',
+      implode('%x00', array('%e', '%cn', '%ce', '%an', '%ae', '%s%n%n%b')),
+      $this->identifier);
+
+    $parts = explode("\0", $info);
+    $encoding = array_shift($parts);
+
+    foreach ($parts as $key => $part) {
+      if ($encoding) {
+        $part = phutil_utf8_convert($part, 'UTF-8', $encoding);
+      }
+      $parts[$key] = phutil_utf8ize($part);
+      if (!strlen($parts[$key])) {
+        $parts[$key] = null;
+      }
+    }
+
+    return id(new DiffusionCommitRef())
+      ->setCommitterName($parts[0])
+      ->setCommitterEmail($parts[1])
+      ->setAuthorName($parts[2])
+      ->setAuthorEmail($parts[3])
+      ->setMessage($parts[4]);
+  }
+
+}
Index: src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryGitCommitMessageParserWorker.php
===================================================================
--- src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryGitCommitMessageParserWorker.php
+++ src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryGitCommitMessageParserWorker.php
@@ -7,32 +7,16 @@
     PhabricatorRepository $repository,
     PhabricatorRepositoryCommit $commit) {
 
-    // NOTE: %B was introduced somewhat recently in git's history, so pull
-    // commit message information with %s and %b instead.
-    // Even though we pass --encoding here, git doesn't always succeed, so
-    // we try a little harder, since git *does* tell us what the actual encoding
-    // is correctly (unless it doesn't; encoding is sometimes empty).
-    list($info) = $repository->execxLocalCommand(
-      'log -n 1 --encoding=%s --format=%s %s --',
-      'UTF-8',
-      implode('%x00', array('%e', '%cn', '%ce', '%an', '%ae', '%s%n%n%b')),
-      $commit->getCommitIdentifier());
-
-    $parts = explode("\0", $info);
-    $encoding = array_shift($parts);
-
-    foreach ($parts as $key => $part) {
-      if ($encoding) {
-        $part = phutil_utf8_convert($part, 'UTF-8', $encoding);
-      }
-      $parts[$key] = phutil_utf8ize($part);
-    }
-
-    $committer_name   = $parts[0];
-    $committer_email  = $parts[1];
-    $author_name      = $parts[2];
-    $author_email     = $parts[3];
-    $message          = $parts[4];
+    $ref = id(new DiffusionLowLevelGitCommitQuery())
+      ->setRepository($repository)
+      ->withIdentifier($commit->getCommitIdentifier())
+      ->execute();
+
+    $committer_name   = $ref->getCommitterName();
+    $committer_email  = $ref->getCommitterEmail();
+    $author_name      = $ref->getAuthorName();
+    $author_email     = $ref->getAuthorEmail();
+    $message          = $ref->getMessage();
 
     if (strlen($author_email)) {
       $author = "{$author_name} <{$author_email}>";