I've gotten things "working" with hg 2.5 - supporting 2.4 isn't really something I'm interested in. Note that the testsuite is still a bit of a basketcase - feel encouraged to look into running the tests to see if you can make it work if you're interested. I'm only somewhat interested in hgit at the moment.
I'm actually actively disinterested in supporting 2.4 - it adds a little code complexity and maintenance burden for something that I don't even really consider reliable anyway. hgit is still a horrifying hack. Run the tests if you don't believe me (they used to all pass).
Probably you've misunderstood me. I've tried your code and it works fine in 2.4 with no further modifications. Which makes me wonder why that second change to gitlog.py wasn't needed — I can't figure it out myself.