diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -6560,7 +6560,7 @@
     'DifferentialDiffRepositoryProjectsHeraldField' => 'DifferentialDiffHeraldField',
     'DifferentialDiffSearchConduitAPIMethod' => 'PhabricatorSearchEngineAPIMethod',
     'DifferentialDiffSearchEngine' => 'PhabricatorApplicationSearchEngine',
-    'DifferentialDiffTestCase' => 'PhutilTestCase',
+    'DifferentialDiffTestCase' => 'PhabricatorTestCase',
     'DifferentialDiffTransaction' => 'PhabricatorApplicationTransaction',
     'DifferentialDiffTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
     'DifferentialDiffViewController' => 'DifferentialController',
diff --git a/src/applications/differential/storage/DifferentialDiff.php b/src/applications/differential/storage/DifferentialDiff.php
--- a/src/applications/differential/storage/DifferentialDiff.php
+++ b/src/applications/differential/storage/DifferentialDiff.php
@@ -780,7 +780,7 @@
     $refs = array();
 
     $branch = $this->getBranch();
-    if (strlen($branch)) {
+    if (phutil_nonempty_string($branch)) {
       $refs[] = array(
         'type' => 'branch',
         'name' => $branch,
@@ -788,7 +788,7 @@
     }
 
     $onto = $this->loadTargetBranch();
-    if (strlen($onto)) {
+    if (phutil_nonempty_string($onto)) {
       $refs[] = array(
         'type' => 'onto',
         'name' => $onto,
@@ -796,7 +796,7 @@
     }
 
     $base = $this->getSourceControlBaseRevision();
-    if (strlen($base)) {
+    if ($base !== null && strlen($base)) {
       $refs[] = array(
         'type' => 'base',
         'identifier' => $base,
@@ -804,7 +804,7 @@
     }
 
     $bookmark = $this->getBookmark();
-    if (strlen($bookmark)) {
+    if (phutil_nonempty_string($bookmark)) {
       $refs[] = array(
         'type' => 'bookmark',
         'name' => $bookmark,
diff --git a/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php b/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php
--- a/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php
+++ b/src/applications/differential/storage/__tests__/DifferentialDiffTestCase.php
@@ -1,6 +1,12 @@
 <?php
 
-final class DifferentialDiffTestCase extends PhutilTestCase {
+final class DifferentialDiffTestCase extends PhabricatorTestCase {
+
+  protected function getPhabricatorTestCaseConfiguration() {
+    return array(
+      self::PHABRICATOR_TESTCONFIG_BUILD_STORAGE_FIXTURES => true,
+    );
+  }
 
   public function testDetectCopiedCode() {
     $copies = $this->detectCopiesIn('lint_engine.diff');
@@ -73,5 +79,40 @@
     $this->assertTrue(true);
   }
 
+  public function testGetFieldValuesForConduit() {
+
+    $parser = new ArcanistDiffParser();
+    $raw_diff = <<<EODIFF
+diff --git a/src b/src
+index 123457..bb216b1 100644
+--- a/src
++++ b/src
+@@ -1,5 +1,5 @@
+ Line a
+-Line b
++Line 2
+ Line c
+ Line d
+ Line e
+EODIFF;
+
+    $diff = DifferentialDiff::newFromRawChanges(
+      PhabricatorUser::getOmnipotentUser(),
+      $parser->parseDiff($raw_diff));
+    $this->assertTrue(true);
+
+    try {
+      $field_values = $diff->getFieldValuesForConduit();
+      $this->assertTrue(is_array($field_values));
+      foreach (['revisionPHID', 'authorPHID', 'repositoryPHID', 'refs']
+        as $key) {
+        $this->assertTrue(array_key_exists($key, $field_values));
+      }
+    } catch (Throwable $ex) {
+      $this->assertTrue(false,
+        'getFieldValuesForConduit threw an exception:'.$ex->getMessage());
+    }
+
+  }
 
 }