git migration: preserve additional metadata (fixed bugs, revision numbers and multiple authors)

[Patrick Storz]

bzr has some metadata that is not supported by git.

So far I know of:
- bugs fixed by the commit
- revision number
- multiple authors

The attached patch modifies Bazaar's fast-export plugin to include those metadata into the commit message so they won't be lost after the migration to git.

[Patrick Storz (ede123)]

There's one downside of this patch: The function "_compute_revno_str()" used to query revision numbers is not overly efficient which results in significantly reduced export performance (approx 3 times slower).

If anybody knows a faster approach let me know.

In any case since this will be a one-time conversion I guess this is acceptable given the fact that revision numbers are quite important as many commit messages reference them.

[Martin Owens (doctormo)]

It's walking the entire tree and counting them, it's got a cache, but it's still a lot of work. add the extra time to walk down side paths... I'd say it's as efficient as it's going to get given the code.

[Patrick Storz (ede123)]

I think this is done ;-)