> I am just recompressing a 77GB file because of this :-(.

Sorry to hear that :(

> I would consider that a bug, not a feature request.

Semantic issues aside, my concern here is that the patch for 2.7 is considerably
larger than the one for 3.3, and the code it modifies is more fragile.

An alternative solution I'd like to pursue is to backport 3.3's BZ2File
implementation to run on 2.7, and release it on PyPI. That way there's no risk
of introducing regressions for people who don't need this facility, and those
who do can get it without needing to upgrade to 2.7.3 (or even wait for it to be
released). It shouldn't take much effort to get it working on 2.6 as well.

How does that sound?