robbyrussell/oh-my-zsh — pull request #1661 by hellerbarde (2013-03-13 23:36:34+00:00)
Title: Fix some problems with git enabled prompts where they *always* claim to have untracked files

the problem was that

grep '^?? '

matches any two characters at the beginning of a line.
so the "## branchname" of a completely clean repository is also matched, which is incorrect.