Compatibility fix for Branch.{get,set}_parent()

[John Arbash Meinel]

As part of the Encoding work, Wouter and I fixed Branch.set_parent() so
that it takes a full URL, but only saves the relative portion if possible.
So the contents of .bzr/branch/parent are always a URL, and relative if
possible.
It means we do weird things with old formats, where they included a
fully absolute local path.
So I added a workaround that would detect this, and change it into a
full url before returning it.
I kept running into this on my branches. I think it is a reasonable fix
and comes with a test case. Can I get a +1?

John
=:->
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: compatibilty-for-parent.diff
Url: https://lists.ubuntu.com/archives/bazaar/attachments/20060615/57ec62ae/attachment.diff 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 254 bytes
Desc: OpenPGP digital signature
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20060615/57ec62ae/attachment.pgp