Oh, supporting %li and %zi is a new feature, it's too late to add this in Python 2.7. I removed this part of my patch. I commited the other part.

PyUnicode_FromFormat() decodes byte strings from ISO 8859-1 for %S, %R and %V formats. I don't like this choice, we should use the default encoding or UTF-8. But it's also probably too late to change that. At least, b'\xff' is decoded to '\xe4' instead of '\xffe4' (signed/unsigned integer issue, also fixed by my patch). It's a little bit better than before.