github pull requests: odd listings of hundreds of commits

Looks like some Github quirk:

    git log master..scottza/fix-autofmt_xdate-twinx

shows only four commits.

The merges done after 2011-02-19 seem to have connected a chunk of
previously unconnected 0_91_maint history to master.

···

On Tue, 17 May 2011 16:14:53 -0400, Michael Droettboom wrote:

Darned if I know what I did differently that time. (I'm sure I hit
git's "misunderstanding" feature again).

It only seems to have affected 2 or 3 of the pull requests -- I suspect
rebasing those branches off of the current master would fix the problem,
but maybe there's an easier way.