diff --git a/src/applications/differential/field/specification/maniphesttasks/DifferentialManiphestTasksFieldSpecification.php b/src/applications/differential/field/specification/maniphesttasks/DifferentialManiphestTasksFieldSpecification.php
index bd1f9c298d..345520e4ca 100644
--- a/src/applications/differential/field/specification/maniphesttasks/DifferentialManiphestTasksFieldSpecification.php
+++ b/src/applications/differential/field/specification/maniphesttasks/DifferentialManiphestTasksFieldSpecification.php
@@ -69,10 +69,13 @@ final class DifferentialManiphestTasksFieldSpecification
     $user = $this->getUser();
     $type = ManiphestTransactionType::TYPE_ATTACH;
     $attach_type = PhabricatorPHIDConstants::PHID_TYPE_DREV;
-    $attach_data = array($revision->getPHID() => array());
 
-    $tasks = id(new ManiphestTask())
-      ->loadAllWhere('phid IN (%Ld)', $this->maniphestTasks);
+    $tasks = array();
+    if ($this->maniphestTasks) {
+      $tasks = id(new ManiphestTask())->loadAllWhere(
+        'phid IN (%Ls)',
+        $this->maniphestTasks);
+    }
 
     foreach ($tasks as $task) {
       $transaction = new ManiphestTransaction();
@@ -80,7 +83,10 @@ final class DifferentialManiphestTasksFieldSpecification
       $transaction->setTransactionType($type);
 
       $new = $task->getAttached();
-      $new[$attach_type] = $attach_data;
+      if (empty($new[$attach_type])) {
+        $new[$attach_type] = array();
+      }
+      $new[$attach_type][$revision->getPHID] = array();
 
       $transaction->setNewValue($new);
       $maniphest_editor->applyTransactions($task, array($transaction));
diff --git a/src/storage/qsprintf/qsprintf.php b/src/storage/qsprintf/qsprintf.php
index befb0f4c73..d955417cef 100644
--- a/src/storage/qsprintf/qsprintf.php
+++ b/src/storage/qsprintf/qsprintf.php
@@ -283,6 +283,11 @@ function _qsprintf_check_scalar_type($value, $type, $query) {
           $query,
           "Expected a scalar or null for %{$type} conversion.");
       }
+      if (!is_numeric($value)) {
+        throw new AphrontQueryParameterException(
+          $query,
+          "Expected numeric value for %{$type} conversion.");
+      }
       break;
 
     case 'Ls': case 's':