Bug (or inconsistency) in git add

I couldn't find a bug tracker for Git, so here's my bug report.

Given a directory containing foo/bar/baz/blah.py and
foo/bar/baz/blem.py, this command:
1)
git add foo/**/*.py

produces no output, and adds no files.

This command:
2)
git add /**.py

produces no output but adds all the files.

This command:
3)
git add foo/**.py

produces an error and adds no files.

IMHO, "git add" should always produce an error message if no files
matched the pathspec given. So case 1) should produce an error
message.

git version 1.7.9.4 on Snow Leopard. (There doesn't seem to be a
1.7.10 at http://code.google.com/p/git-osx-installer/downloads/list?can=3)

If this is some weird bash shell behaviour, my apologies.

Steve