We are going to truncate overly long lines returned from git log, and the most
likely field that is going to make the line too long is the subject; so we must
put it last, otherwise we'd end up with not enough fields to split when it's too
long.
It might not be obvious from the diff what's happening to the mock command
output in the test: it didn't have the divergence field (">") at all, which was
kind of a bug. It didn't matter for these tests though, because we are not
testing the divergence here, and our production code happens to be resilient
against it missing. But now we must add the ">" field before the subject.
e0a2d97f0f