It turns out that librpm automatically merges identical files between
distinct packages, and this occurs in practice with Fedora today between
`chkconfig` and `initscripts` for exmaple.
Since we added this for rpm-ostree, we basically want to do what librpm does,
let's change the semantics to do a merge. While we're here rename
to `UNION_IDENTICAL`.
Closes: #1156
Approved by: jlebon
This is for issue projectatomic/rpm-ostree#365,
an extra option of overwrite mode is added to the checkout command
so that when there is "non-directory" file already exist
during checkout, the error will be handled.
Some tests are added for regression
Closes: #1116
Approved by: cgwalters
Colin Walters
Ruixin