Ubiquity allows invalid group name (> 32 characters)

Status changed to 'Confirmed' because the bug affects multiple users.

I've committed a fix to user-setup upstream.

This bug was fixed in the package ubiquity - 2.9.20

---------------
ubiquity (2.9.20) precise; urgency=low

  [ Colin Watson ]
  * Restore old fallback code in case /cdrom/casper/filesystem.size doesn't
    exist (LP: #557388).
  * Fix some more uses of deprecated python-apt APIs.
  * ubiquity-dm: Try openbox after openbox-lubuntu (LP: #888107).
  * Thomson SA is now called Technicolor SA (LP: #856992).
  * Limit maximum length of username editing widgets to 32 (LP: #831319).
  * UTF-8-encode the syslog message when a geoname lookup fails, since it
    might include non-ASCII characters entered by the user (LP: #928891).
  * Run test suite under xvfb-run by default when running it from the
    command line. 'tests/run --no-xvfb' inhibits this behaviour for cases
    where it's useful to see the UIs constructed by the test suite.
  * Stop manually inserting newlines in hostname and username errors. GTK+
    3 seems to do a reasonable job of wrapping these by itself now.
  * Port the user page from GtkTable to GtkGrid, so that we get sensible
    height-for-width geometry management (LP: #830933).
  * Internationalise hostname and username validation errors (LP: #784825).

  [ Mario Limonciello ]
  * Have two separate failsafe attempts for 'fbdev' and 'vesa'. It's
    possible that /dev/fb0 will exist but be backed by a VGA framebuffer
    causing X to exit non-zero.

  [ Stéphane Graber ]
  * Use the Xubuntu wallpaper when available. (LP: #936572)
  * Detect bogus DNS servers and ignore them. (LP: #760884)
  * Automatic update of included source packages: base-installer
    1.122ubuntu5, choose-mirror 2.39ubuntu4.
 -- Stephane Graber <email address hidden> Tue, 21 Feb 2012 21:09:02 -0500

user-setup 1.41ubuntu1 uploaded to precise, including:

user-setup (1.41) unstable; urgency=low

  * Check that usernames are no more than 32 characters long (closes:
    #571750).

  [ Updated translations ]
  * Arabic (ar.po) by Ossama Khayat
  * Asturian (ast.po) by Mikel González
  * Belarusian (be.po) by Viktar Siarheichyk
  * Bulgarian (bg.po) by Damyan Ivanov
  * Bosnian (bs.po) by Armin Besirovic
  * Catalan (ca.po) by Jordi Mallach
  * Czech (cs.po) by Miroslav Kure
  * Danish (da.po) by Joe Hansen
  * German (de.po) by Holger Wansing
  * Greek, Modern (1453-) (el.po)
  * Esperanto (eo.po) by Felipe Castro
  * Spanish (es.po) by Javier Fernández-Sanguino
  * Estonian (et.po) by Mattias Põldaru
  * Persian (fa.po) by Hamid
  * French (fr.po) by Christian Perrier
  * Hindi (hi.po) by Kumar Appaiah
  * Indonesian (id.po) by Mahyuddin Susanto
  * Icelandic (is.po) by Sveinn í Felli
  * Italian (it.po) by Milo Casagrande
  * Japanese (ja.po) by Kenshi Muto
  * Kazakh (kk.po) by Baurzhan Muftakhidinov
  * Kannada (kn.po) by Prabodh C P
  * Korean (ko.po) by Changwoo Ryu
  * Marathi (mr.po) by sampada
  * Dutch (nl.po) by Jeroen Schot
  * Polish (pl.po) by Marcin Owsiany
  * Portuguese (pt.po) by Miguel Figueiredo
  * Russian (ru.po) by Yuri Kozlov
  * Sinhala (si.po) by Danishka Navin
  * Slovak (sk.po) by Ivan Masár
  * Serbian (sr.po) by Karolina Kalic
  * Swedish (sv.po) by Martin Bagge / brother
  * Thai (th.po) by Kiatkachorn Ratanatharathorn
  * Turkish (tr.po) by Mert Dirik
  * Uyghur (ug.po) by Sahran
  * Simplified Chinese (zh_CN.po) by YunQiang Su

 -- Colin Watson <email address hidden> Wed, 07 Mar 2012 23:56:11 +0000