Description of problem:

The 'Additional Language Support' portion of Anaconda will crash if no
languages are ticked at any point.

The behaviour of Anaconda prior to the Fedora Core 3 test releases was
that at least one language must be ticked at any one time, if only one
language was ticked (i.e. English USA), the user must tick another
language (i.e. English UK) and then untick the default language (i.e.
English USA).

If only one language was ticked, Anaconda would *not* let you untick it.

This release of Anaconda (I have not verified if problem exists in
earlier Fedora Core 3 test releases) generates an immediate Python
traceback if the default language, English USA, is unticked *prior* to
selecting a second language.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Boot Fedora Core 3 Test 3 CD #1.
2. Proceed with installation as normal until you get to the
'Additional Language Support' portion of Anaconda.
3. Untick the 'English (USA)' language.
  
Actual results:

The traceback generated by Anaconda is below:

Traceback (most recent call last):
 File
"/usr/src/build/451389-i386/install//usr/lib/anaconda/iw/language_support_gui.py",
 line 66, in toggled_language
 self.rebuild_combo();
 File
"/usr/src/build/451389-i386/install//usr/lib/anaconda/iw/language_support_gui.py",
 line 84, in rebuild_combo
 self.defaultLang = self.deflang_values[curidx]
IndexError: list index out of range

Expected results:

Anaconda should either not allow the initial default language to be
unticked until at least one other language is ticked.

In simple terms, it should behave more like earlier versions of
Anaconda (see any version of Anaconda which ships with Red Hat Linux
8.0 or later).

Additional info:

I have temporarily worked around the problem by ticking the preferred
language before unticking English (USA), like so:

1:) English USA [X]
    English UK [X]     <--- Tick English UK first.

3:) English USA [ ]    <--- ... then untick English USA.
    English UK [X]