Index: sites/default/modules/contrib/webform/webform.module
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- sites/default/modules/contrib/webform/webform.module	(revision d1ec08f1bea915c33c844d949fe696d9d245c244)
+++ sites/default/modules/contrib/webform/webform.module	(revision a4164bddc226f0aa1ba3f6b095ff130e96254c1d)
@@ -3046,7 +3046,7 @@
     // #value data.
     elseif (isset($elements['#element_validate'])) {
       foreach ($elements['#element_validate'] as $function) {
-        if (function_exists($function))  {
+        if (is_callable($function))  {
           $function($elements, $form_state, $form_state['complete form']);
         }
       }