diff --git a/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php b/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php
--- a/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php
+++ b/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php
@@ -655,7 +655,12 @@
     $epoch,
     $task_priority) {
 
-    $this->insertTask($repository, $commit, $task_priority);
+    $this->queueCommitImportTask(
+      $repository,
+      $commit->getID(),
+      $commit->getPHID(),
+      $task_priority,
+      $via = 'discovery');
 
     // Update the repository summary table.
     queryfx(
@@ -679,36 +684,6 @@
     }
   }
 
-  private function insertTask(
-    PhabricatorRepository $repository,
-    PhabricatorRepositoryCommit $commit,
-    $task_priority,
-    $data = array()) {
-
-    $vcs = $repository->getVersionControlSystem();
-    switch ($vcs) {
-      case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
-        $class = 'PhabricatorRepositoryGitCommitMessageParserWorker';
-        break;
-      case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
-        $class = 'PhabricatorRepositorySvnCommitMessageParserWorker';
-        break;
-      case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
-        $class = 'PhabricatorRepositoryMercurialCommitMessageParserWorker';
-        break;
-      default:
-        throw new Exception(pht("Unknown repository type '%s'!", $vcs));
-    }
-
-    $data['commitID'] = $commit->getID();
-
-    $options = array(
-      'priority' => $task_priority,
-    );
-
-    PhabricatorWorker::scheduleTask($class, $data, $options);
-  }
-
   private function isInitialImport(array $refs) {
     $commit_count = count($refs);
 
@@ -926,71 +901,4 @@
       $data['epoch']);
   }
 
-  private function getImportTaskPriority(
-    PhabricatorRepository $repository,
-    array $refs) {
-
-    // If the repository is importing for the first time, we schedule tasks
-    // at IMPORT priority, which is very low. Making progress on importing a
-    // new repository for the first time is less important than any other
-    // daemon task.
-
-    // If the repository has finished importing and we're just catching up
-    // on recent commits, we usually schedule discovery at COMMIT priority,
-    // which is slightly below the default priority.
-
-    // Note that followup tasks and triggered tasks (like those generated by
-    // Herald or Harbormaster) will queue at DEFAULT priority, so that each
-    // commit tends to fully import before we start the next one. This tends
-    // to give imports fairly predictable progress. See T11677 for some
-    // discussion.
-
-    if ($repository->isImporting()) {
-      $this->log(
-        pht(
-          'Importing %s commit(s) at low priority ("PRIORITY_IMPORT") '.
-          'because this repository is still importing.',
-          phutil_count($refs)));
-
-      return PhabricatorWorker::PRIORITY_IMPORT;
-    }
-
-    // See T13369. If we've discovered a lot of commits at once, import them
-    // at lower priority.
-
-    // This is mostly aimed at reducing the impact that synchronizing thousands
-    // of commits from a remote upstream has on other repositories. The queue
-    // is "mostly FIFO", so queueing a thousand commit imports can stall other
-    // repositories.
-
-    // In a perfect world we'd probably give repositories round-robin queue
-    // priority, but we don't currently have the primitives for this and there
-    // isn't a strong case for building them.
-
-    // Use "a whole lot of commits showed up at once" as a heuristic for
-    // detecting "someone synchronized an upstream", and import them at a lower
-    // priority to more closely approximate fair scheduling.
-
-    if (count($refs) >= PhabricatorRepository::LOWPRI_THRESHOLD) {
-      $this->log(
-        pht(
-          'Importing %s commit(s) at low priority ("PRIORITY_IMPORT") '.
-          'because many commits were discovered at once.',
-          phutil_count($refs)));
-
-      return PhabricatorWorker::PRIORITY_IMPORT;
-    }
-
-    // Otherwise, import at normal priority.
-
-    if ($refs) {
-      $this->log(
-        pht(
-          'Importing %s commit(s) at normal priority ("PRIORITY_COMMIT").',
-          phutil_count($refs)));
-    }
-
-    return PhabricatorWorker::PRIORITY_COMMIT;
-  }
-
 }
diff --git a/src/applications/repository/engine/PhabricatorRepositoryEngine.php b/src/applications/repository/engine/PhabricatorRepositoryEngine.php
--- a/src/applications/repository/engine/PhabricatorRepositoryEngine.php
+++ b/src/applications/repository/engine/PhabricatorRepositoryEngine.php
@@ -83,4 +83,114 @@
     return $this;
   }
 
+  final protected function queueCommitImportTask(
+    PhabricatorRepository $repository,
+    $commit_id,
+    $commit_phid,
+    $task_priority,
+    $via = null) {
+
+    $vcs = $repository->getVersionControlSystem();
+    switch ($vcs) {
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
+        $class = 'PhabricatorRepositoryGitCommitMessageParserWorker';
+        break;
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
+        $class = 'PhabricatorRepositorySvnCommitMessageParserWorker';
+        break;
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
+        $class = 'PhabricatorRepositoryMercurialCommitMessageParserWorker';
+        break;
+      default:
+        throw new Exception(
+          pht(
+            'Unknown repository type "%s"!',
+            $vcs));
+    }
+
+    $data = array(
+      'commitID' => $commit_id,
+    );
+
+    if ($via !== null) {
+      $data['via'] = $via;
+    }
+
+    $options = array(
+      'priority' => $task_priority,
+      'objectPHID' => $commit_phid,
+    );
+
+    PhabricatorWorker::scheduleTask($class, $data, $options);
+  }
+
+  final protected function getImportTaskPriority(
+    PhabricatorRepository $repository,
+    array $refs) {
+    assert_instances_of($refs, 'PhabricatorRepositoryCommitRef');
+
+    // If the repository is importing for the first time, we schedule tasks
+    // at IMPORT priority, which is very low. Making progress on importing a
+    // new repository for the first time is less important than any other
+    // daemon task.
+
+    // If the repository has finished importing and we're just catching up
+    // on recent commits, we usually schedule discovery at COMMIT priority,
+    // which is slightly below the default priority.
+
+    // Note that followup tasks and triggered tasks (like those generated by
+    // Herald or Harbormaster) will queue at DEFAULT priority, so that each
+    // commit tends to fully import before we start the next one. This tends
+    // to give imports fairly predictable progress. See T11677 for some
+    // discussion.
+
+    if ($repository->isImporting()) {
+      $this->log(
+        pht(
+          'Importing %s commit(s) at low priority ("PRIORITY_IMPORT") '.
+          'because this repository is still importing.',
+          phutil_count($refs)));
+
+      return PhabricatorWorker::PRIORITY_IMPORT;
+    }
+
+    // See T13369. If we've discovered a lot of commits at once, import them
+    // at lower priority.
+
+    // This is mostly aimed at reducing the impact that synchronizing thousands
+    // of commits from a remote upstream has on other repositories. The queue
+    // is "mostly FIFO", so queueing a thousand commit imports can stall other
+    // repositories.
+
+    // In a perfect world we'd probably give repositories round-robin queue
+    // priority, but we don't currently have the primitives for this and there
+    // isn't a strong case for building them.
+
+    // Use "a whole lot of commits showed up at once" as a heuristic for
+    // detecting "someone synchronized an upstream", and import them at a lower
+    // priority to more closely approximate fair scheduling.
+
+    if (count($refs) >= PhabricatorRepository::LOWPRI_THRESHOLD) {
+      $this->log(
+        pht(
+          'Importing %s commit(s) at low priority ("PRIORITY_IMPORT") '.
+          'because many commits were discovered at once.',
+          phutil_count($refs)));
+
+      return PhabricatorWorker::PRIORITY_IMPORT;
+    }
+
+    // Otherwise, import at normal priority.
+
+    if ($refs) {
+      $this->log(
+        pht(
+          'Importing %s commit(s) at normal priority ("PRIORITY_COMMIT").',
+          phutil_count($refs)));
+    }
+
+    return PhabricatorWorker::PRIORITY_COMMIT;
+  }
+
+
 }
diff --git a/src/applications/repository/engine/PhabricatorRepositoryRefEngine.php b/src/applications/repository/engine/PhabricatorRepositoryRefEngine.php
--- a/src/applications/repository/engine/PhabricatorRepositoryRefEngine.php
+++ b/src/applications/repository/engine/PhabricatorRepositoryRefEngine.php
@@ -548,6 +548,22 @@
       }
     }
 
+    $commit_refs = array();
+    foreach ($identifiers as $identifier) {
+
+      // See T13591. This construction is a bit ad-hoc, but the priority
+      // function currently only cares about the number of refs we have
+      // discovered, so we'll get the right result even without filling
+      // these records out in detail.
+
+      $commit_refs[] = id(new PhabricatorRepositoryCommitRef())
+        ->setIdentifier($identifier);
+    }
+
+    $task_priority = $this->getImportTaskPriority(
+      $repository,
+      $commit_refs);
+
     $permanent_flag = PhabricatorRepositoryCommit::IMPORTED_PERMANENT;
     $published_flag = PhabricatorRepositoryCommit::IMPORTED_PUBLISH;
 
@@ -580,17 +596,12 @@
           $import_status,
           $row['id']);
 
-        $data = array(
-          'commitID' => $row['id'],
-        );
-
-        PhabricatorWorker::scheduleTask(
-          $class,
-          $data,
-          array(
-            'priority' => PhabricatorWorker::PRIORITY_COMMIT,
-            'objectPHID' => $row['phid'],
-          ));
+        $this->queueCommitImportTask(
+          $repository,
+          $row['id'],
+          $row['phid'],
+          $task_priority,
+          $via = 'ref');
       }
     }