add check for valid uri

Author: shinobu

application/controllers/ModelController.php

@@ -503,6 +503,13 @@ public function createAction()
                 );
                 $this->view->errorFlag = true;
                 return;
+            } else if (substr($newModelUri, 0, 8) != 'https://'
+                && substr($newModelUri, 0, 7) != 'http://'
+                && substr($newModelUri, 0, 4) != 'urn:'
+            ) {
+                $this->_owApp->appendMessage(
+                    new OntoWiki_Message('The given String is no legal URI (http://...)', OntoWiki_Message::ERROR)
+                );
             } else {
                 // model does not exist, will be created
                 $model = $store->getNewModel(