We believe that your issue has been closed by the upload of
Version 0.3.84 of grml-etc-core from Michael Prokop <mika@grml.org>.
The explanation is attached below

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Format: 1.8
Date: Mon, 08 Nov 2010 11:54:26 +0100
Source: grml-etc-core
Binary: grml-etc-core
Architecture: source all
Version: 0.3.84
Distribution: unstable
Urgency: low
Maintainer: Michael Prokop <mika@grml.org>
Changed-By: Michael Prokop <mika@grml.org>
Description: 
 grml-etc-core - core ecetera files for the grml system
Changes: 
 grml-etc-core (0.3.84) unstable; urgency=low
 .
   [ Frank Terbeck ]
   * zshrc: Remove git-get-*() as discussed on IRC.
   * zshrc: Fixied a bug in whatwhen(); found be Joerg Woelke.
   * zshrc: Added a note about modifying the zshrc file when it is
     used as ~/.zshrc
   * zshrc: Disable `vcs_info' in restricted shells.
   * grmlzshrc.t2t: Remove references to git-get-*().
   * Added zsh-lookup subsystem from <https://github.com/ft/zsh-lookup>.
 .
   [ Carsten Hey ]
   * zshrc: Rename new() to modified().
   * zshrc: Load zsh/stat as zstat instead of stat.
   * zshrc: fix typo in default value handling of changed() and new()
     (now modified()).
 .
   [ Joerg Woelke ]
   * zshrc: Comment out the non-working `zurl' function.
   * grmlzshrc.t2t: documentation updates.
   * zshrc: Improve weather() function.
   * zshrc: Remove functions gethgclone() and gethgsnap()
   * zshrc: zshrc: Fix iwclient().
   * zshrc: Fix passing of args in cdiff().
 .
   [ Ulrich Dangel ]
   * zshrc: Remove get{air,gizmo,skype,skypebeta,xlite} functions.
   * vimrc: Enable "persistent undo" if possible. [Closes: issue909]
     [Closes: issue927]
 .
   [ Michael Prokop ]
   * /etc/skel/.gitconfig: drop core.pager option (less -Mr) causing
     terminal problems.
   * Bump Standards-Version to 3.9.1.
Checksums-Sha1: 
 271f1bf139d4c0b675f67e98ad064f879e8c7922 888 grml-etc-core_0.3.84.dsc
 58d2b930214eb358f711294f602366c1b6c0cef5 152726 grml-etc-core_0.3.84.tar.gz
 ea50c704fc010ed7ba5a460ddfcb9d30c405d245 158316 grml-etc-core_0.3.84_all.deb
Checksums-Sha256: 
 e4985b1cb7c7de6adae469a8dfc2acb49f65ef486f4277914edde96e3c036c0b 888 grml-etc-core_0.3.84.dsc
 84d9925838277dc4f099f8e7eabdbac3045318776eb7d4c46ecc3831d6ab23ae 152726 grml-etc-core_0.3.84.tar.gz
 0093ad66b334e26d62f643f6c1ed0be44be3cda63890e48875d31f9931baf8d7 158316 grml-etc-core_0.3.84_all.deb
Files: 
 9a39c8bf6f1cc68438d0b58d95807e81 888 grml optional grml-etc-core_0.3.84.dsc
 4db5ce41095a269043b5e34cbaf8fea2 152726 grml optional grml-etc-core_0.3.84.tar.gz
 d623fa577684adc47e3b9c0da8f0bc53 158316 grml optional grml-etc-core_0.3.84_all.deb

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)

iEYEARECAAYFAkzYKfYACgkQ2N9T+zficuioYACfZx51Z0rH2MwsPHpCZuGn++5o
Oo8An3ldqTRuYGI7x/mb8avT+cKyt1No
=1O/L
-----END PGP SIGNATURE-----

* Frank Terbeck wrote [21.09.10 09:28]:
Hi,
> When does vim store this information? If it's just upon `:quit', I
> don't think there's any reason not to do this (although vim's
> undo-trees can become rather big).

After writing a file:
,----[he persistent-undo]
| The 'undofile' option is checked after writing a file, before the BufWritePost       
| autocommands.  If you want to control what files to write undo information           
| for, you can use a BufWritePre autocommand: >                                        
`----


Ulrich

Ulrich Dangel <bts@bts.grml.org>:
> I just discovered the persistent undo option in vim. Basically it
> saves undo information in a file. I would love to get that
> integrated in our vimrc.
> 
> Basically you just have to set undofile in the vimrc and the feature
> will be enabled. Maybe undodir should also be set to something like
> ~/.vim/ as it creates additional hidden files.

When does vim store this information? If it's just upon `:quit', I
don't think there's any reason not to do this (although vim's
undo-trees can become rather big).

Regards, Frank

I just discovered the persistent undo option in vim. Basically it saves undo 
information in a file. I would love to get that integrated in our vimrc.

Basically you just have to set undofile in the vimrc and the feature will be 
enabled. Maybe undodir should also be set to something like ~/.vim/ as it 
creates additional hidden files.