Fix possible NULL-dereference in e_cal_backend_file_modify_objects()
e_cal_backend_file_modify_objects(…, GSList **old_components,…) starts with
if (old_components) *old_components = NULL;
so it can be called with old_components==NULL and then *old_components is invalid (NULL-dereference).
On line 2703 the function contains:
if (*old_components)
*old_components = g_slist_prepend (*old_components, obj_data->full_object ? e_cal_component_clone (obj_data->full_object) : NULL);
The if
-line contains a NULL-dereference.