"/webform-results/download-file": Not null violation: 7

Hi,

i receive the next error during report download:

PDOException: SQLSTATE[23502]: Not null violation: 7 
ERROR: el valor null para la columna «sid» viola la restricción not null: 
INSERT INTO webform_last_download (nid, uid, sid, requested) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3); 
Array ( ) en webform_results_download() (línea 1071 de /var/www/html/sites/all/modules/webform/includes/webform.report.inc).

I need to edit the function "webform_results_download($node, $export_info)" and verify that:

• $export_info['last_sid']

Not are empty.

File: sites/all/modules/webform/includes/webform.report.inc
Line: 1071

if ( !isset( $export_info['last_sid'] ) || empty( $export_info['last_sid'] ) || is_null( $export_info['last_sid'] ) ) {
	$export_info['last_sid'] = 0;
}