git init shared=group with a subdir

I believe there may be a bug when initializing a new repository relating 
to the directory permissions when the --shared=group option is used and 
the repository is within a sub-directory.

The following will create the "test.git" directory with 2775 permissions 
(which is as expected):

   $ ls -ld test.git
   ls: cannot access test.git: No such file or directory
   $ git init --bare --shared=group test.git
   Initialized empty shared Git repository in /tmp/test.git/
   $ ls -ld test.git
   drwxrwsr-x 7 pete users 4096 2012-11-14 11:15 test.git

This following will also create the "test.git" directory with 2775 
permissions, BUT the "subdir" directory ends up with 755 permissions:

   $ ls -ld subdir
   ls: cannot access subdir: No such file or directory
   $ git init --bare --shared=group subdir/test.git
   Initialized empty shared Git repository in /tmp/subdir/test.git/
   $ ls -ld subdir subdir/test.git
   drwxr-xr-x 3 pete users 4096 2012-11-14 11:16 subdir
   drwxrwsr-x 7 pete users 4096 2012-11-14 11:16 subdir/test.git

Assuming the "subdir" directory doesn't already exist and is created by 
the "git init" command AND the --shared=group option is used, then 
shouldn't the "subdir" directory also have 2775 permissions?