git-1.7.3 breakage: "git stash show xxx" doesn't show anything

Downstream bug: http://bugs.gentoo.org/338586

telling git-stash to show a specific stash no longer works with git-1.7.3:
  git stash show stash@{0}
  <no output!?>

Downgrading to dev-vcs/git-1.7.2.3 and it works fine. Noticed on two stable amd64 systems.

Reproduction:
$ rm -rf foo && mkdir foo && cd foo
$ git init
Initialized empty Git repository in /home/vapier/foo/.git/
$ echo f > f && git add f && git commit -qmm
$ > f
$ git stash
Saved working directory and index state WIP on master: d287dea m
HEAD is now at d287dea m
$ git stash list | cat
stash@{0}: WIP on master: d287dea m
$ git stash show | cat
 f |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
$ git stash show stash@{0} | cat
<nothing!>