rem: sub_category -> sub_category_name = g_strdup (name);
add: if ( name ) sub_category -> sub_category_name = g_strdup (name); else sub_category -> sub_category_name = NULL;
context: gboolean gsb_data_category_set_sub_category_name ( gint no_category,						   gint no_sub_category,						   const gchar *name ){    struct_sub_category *sub_category;    sub_category = gsb_data_category_get_sub_category_structure ( no_category,								  no_sub_category );    if (!sub_category)	return FALSE;    /* we free the last name */    if ( sub_category -> sub_category_name )	free (sub_category -> sub_category_name);    /* and copy the new one */    sub_category -> sub_category_name = g_strdup (name);    return TRUE;}