[MERGE][Trivial] invalid version tuple attempt to raise AssertionError fails with TypeError

[Martin Pool]

Martin Pool has voted approve.
Status is now: Semi-approved
Comment:
Yep, classic Python trap - I've applied your patch.

 > I couldn't find any existing tests relating to version tuple 
formatting,
> otherwise I would have added a test for this case.

Actually they're right under your nose - the docstring includes 
doctests.

(What's already there is a reasonable use of doctests to give testable 
examples, though testing how every error is handled tends to make them 
too long as documentation.)

I'll merge it.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C033f01c91ac9%24a06e6d70%24e14b4850%24%40com.au%3E
Project: Bazaar