> Doing two separate commits is probably better.

Out of curiosity, what is typically the convention on that?  The 
devguide seems to suggest one changeset per issue:

"""
Just please make sure that you generate a single, condensed patch rather than a series of several changesets.
"""

I think for this case two patches is better.  In general, I am OK with
the git-style series and hg-style patchbombs, but the devguide seems
to say otherwise.  Hmmm, that makes me wonder if we can patchbomb the
tracker :-)