While in a *vc-dir* buffer (backed by git) and trying to show or apply a
stash fails.

I am attaching "works for me" patch that shell-quotes stash@{n}
argument. With this "patch", the stash commands work as expected.

My shell-file-name is set to "bash" (cygwin version). My Emacs is

In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2011-09-06 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.5) --no-opt'

Additional Info:

,----
| VC backend : Git
| Working dir: ~/src/org-mode/
| Branch     : master
| Remote     : orgmode@orgmode.org:org-mode.git
| Stash      :
|              {0}: On master: custom tables  <-----
`----

FWIW, the stash line has following keymap:

,----
| (keymap
|  (83 . vc-git-stash-snapshot)
|  (80 . vc-git-stash-pop-at-point)
|  (65 . vc-git-stash-apply-at-point)
|  (13 . vc-git-stash-show-at-point)
|  (61 . vc-git-stash-show-at-point)
|  (11 . vc-git-stash-delete-at-point)
|  (down-mouse-3 . vc-git-stash-menu)
|  (mouse-2 . ignore))
`----