Doing a git add '' will add more files then expected

Hello,

I first asked on stackoverflow
(http://stackoverflow.com/questions/26933761/python-sh-module-and-git-try-to-add-more-files-then-in-command/26934517#26934517)
about this behaviour.

Then on the conversation that happened on the git-users mailing list
other agreed that this behaviour is probably not as intended.

Steps to reproduce:
In bash (not sure this is bash specific) do:
git add ''
(that's to apostrophes, an empty argument)

Results
same as doing git add .

Expected
no files added or error about not finding file ''

Hope this helps.
Guilherme