pkgng/pkgng — pull request #144 by culot (2012-02-06 18:02:03+00:00)
Title: Avoid an abort trap when trying to restore an empty database.

Simple check added to make sure pkg does not dump core when using 'pkg backup -r db.txz' with db.txz being an empty database.
To reproduce, simply issue the following commands with no packages installed:

$ pkg backup -d db
$ pkg backup -r db.txz