[5.2] EmailRule unique should look at submitted input data instead of stored form data. (joomla#43822)

Author: Flowman

libraries/src/Form/Rule/EmailRule.php

@@ -164,7 +164,9 @@ public function test(\SimpleXMLElement $element, $value, $group = null, ?Registr
             $query = $db->getQuery(true);
 
             // Get the extra field check attribute.
-            $userId = ($form instanceof Form) ? (int) $form->getValue('id') : 0;
+            $userId = ($form instanceof Form) && $form->getValue('id')
+                ? (int) $form->getValue('id')
+                : (($input instanceof Registry) ? (int) $input->get('id') : 0);
 
             // Build the query.
             $query->select('COUNT(*)')