branch creates a folder when source branch doesn't exist

[Adrian Wilkins]

bzr branch creates the target folder before it verifies the source branch exists. This is mildly annoying when you fluff a link and have to clean up the folder so created.

# I'll just grab a local branch ....
adrian@motoko:~/nhsdd/workspace$ bzr branch http://some.repo.com/repository/model.cp1017
bzr: ERROR: Not a branch: "http://www.datadictionary.nhs.uk/repository/model.cp1017/".

# Darn, that server doesn't support dumb-http
adrian@motoko:~/nhsdd/workspace$ bzr branch bzr+http://some.repo.com/repository/model.cp1017
bzr: ERROR: Target directory "model.cp1017" already exists.

# Curses
rm -rf model.cp1017
adrian@motoko:~/nhsdd/workspace$ bzr branch bzr+http://some.repo.com/repository/model.cp1017
Branched 42 revision(s).