git rev-parse --git-dir does report yield relative path to git directory, per documentation

Per this advice in git-rev-parse(1):

     Show $GIT_DIR if defined. Otherwise show the path to the .git
directory, relative to the current directory.

I had expected this:

cd /tmp &&
rm -rf foobar &&
mkdir foobar &&
cd foobar &&
git init &&
mkdir tmp &&
:> tmp/.gitignore &&
git add tmp &&
cd tmp &&
git rev-parse --git-dir

to report:

Initialized empty Git repository in /tmp/foobar/.git/
../.git

but in actual fact it reports:

Initialized empty Git repository in /tmp/foobar/.git/
/tmp/foobar/.git

git version 1.7.10.1.514.ge33c7ea

Am I misunderstanding the meaning of the term "relative" in quote above?

jon.