Don't try to enable a NULL device
If there is no other libinput device in our list (and next is thus NULL), skip the xf86AddEnabledDevice() call.
Fixes #60 (closed) (second part, see !48 (merged) for the first part)
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
If there is no other libinput device in our list (and next is thus NULL), skip the xf86AddEnabledDevice() call.
Fixes #60 (closed) (second part, see !48 (merged) for the first part)