[Bug] git add -i fails in multiple ways prior to first commit.

$ git init
$ touch foo.txt
$ git add foo.txt
$ git add -i
fatal: bad revision 'HEAD'
            staged     unstaged path

*** Commands ***
   1: [s]tatus	  2: [u]pdate	  3: [r]evert	  4: [a]dd untracked
   5: [p]atch	  6: [d]iff	  7: [q]uit	  8: [h]elp
What now>

* status fails to report the current status
* update fails to work at all
* revert fails to work (not that there should be anything to revert  
but it shouldn't return a "fatal: bad revision 'HEAD'" message.
* add untracked works
* patch works
* diff fails
* help returns instructions that are incorrect owing to the fact that  
half of the things don't work in this state.
* quit, thankfully, works. :)

Why this is important: git add's interactive mode is intended to make things easier, thus it stands to reason that people new to git are going to want to use it. Presenting them with so many broken commands so early on is, obviously, a really bad idea.

-masukomi