Re: destroy ppp(4) on closing tty

[Greg Troxel <gdt%ir.bbn.com@localhost>]

  I have no strong opinion, but either of those seem more consistent to
  me than to make close() behave differently depending on history of the
  device.

The point is that if an open() call caused the device to start existing,
it makes sense for the last close() to destroy it.  I would say that if
we don't want this behavior we shouldn't allow create on open.