Fix for bug #1160 : reset sql_mode

lib/MySQL_Session.cpp

@@ -918,7 +918,7 @@ bool MySQL_Session::handler_again___verify_backend_sql_log_bin() {
 bool MySQL_Session::handler_again___verify_backend_sql_mode() {
 	if (mybe->server_myds->myconn->options.sql_mode_int==0) {
 		// it is the first time we use this backend. Set sql_mode to default
-		if (mybe->server_myds->myconn->options.sql_mode==NULL) {
+		if (mybe->server_myds->myconn->options.sql_mode) {
 			free(mybe->server_myds->myconn->options.sql_mode);
 			mybe->server_myds->myconn->options.sql_mode=NULL;
 		}

lib/mysql_connection.cpp

@@ -1659,6 +1659,13 @@ void MySQL_Connection::reset() {
 	status_flags=0;
 	reusable=true;
 	options.last_set_autocommit=-1; // never sent
+	{ // bug #1160
+		options.sql_mode_int = 0;
+		if (options.sql_mode) {
+			free(options.sql_mode);
+			options.sql_mode = NULL;
+		}
+	}
 	delete local_stmts;
 #ifndef PROXYSQL_STMT_V14
 	local_stmts=new MySQL_STMTs_local(false);