#919348: unset form values fail the validation for #options elements.

From: Damien Tournoud <damien@commerceguys.com>


---
 form.inc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git includes/form.inc includes/form.inc
index efbbe5a..84f55ac 100644
--- includes/form.inc
+++ includes/form.inc
@@ -1883,7 +1883,7 @@ function _form_builder_handle_input_element($form_id, &$element, &$form_state) {
       // Avoid image buttons (which come with garbage value), so we only get value
       // for the button actually clicked.
       if (!isset($element['#value']) && empty($element['#has_garbage_value'])) {
-        $element['#value'] = isset($element['#default_value']) ? $element['#default_value'] : '';
+        $element['#value'] = isset($element['#default_value']) ? $element['#default_value'] : NULL;
       }
     }
   }