+branch aliases fail to resolve if they contain 'bzr'

[Aaron Bentley]

Iwata reported earlier today that lp:qbzr and lp:tortoisebzr are
currently broken. The real branch locations, like
lp:~qbzr-dev/qbzr/trunk2a still work fine, but
bzr+ssh://bazaar.launchpad.net/+branch/qbzr and bzr+ssh://bazaar.launchpad.net/+branch/qbzr/trunk fail to resolve.

Similarly, the API's getBranchByUrl does not resolve these branches.

From talking to Aaron, this is probably fallout from r16509.

What's slightly mysterious is there's nothing obviously different
about this two branches that isn't also true about branches that do
still work. Both had their trunk moved in the past, but other projects
that have done that are not affected.

[William Grant (wgrant)]

The regular expression in BranchLookup.getByLPPath is wrong. Escaping the "." in ".bzr" fixes it.

>>> import re
>>> path = 'foobzr'
>>> re.match('^(.*?)(/?.bzr(/.*)?)?$', path).group(1)
'fo'
>>> re.match('^(.*?)(/?\.bzr(/.*)?)?$', path).group(1)
'foobzr'

[William Grant (wgrant)]

The introduction of that regex is also the cause of bug #1025368. So this bug will probably be fixed when the regex is necessarily removed.