Bug#1110661: debian-live: installing trixie lxde live image in non-Thai locale results in non-functional Thai X Terminal

Package: debian-live
Severity: normal
Control: affects -1 + xiterm+thai
X-Debbugs-Cc: [email protected], [email protected]

Found during 13.0 release testing (originally by sqrt on #debian-cd, but 
I can reproduce it).

Steps to reproduce
==================

* Boot debian-live-13.0.0-amd64-lxde.iso
* Install using Calamares, selecting a non-Thai locale
  (I used British English, en_GB)
* Reboot to the installed system
* main menu → System
* If "Thai X Terminal" (the xiterm+thai package) appears, launch it
* try to type some command, e.g. grep --help

Expected result
===============

* Either:
    - the Thai X Terminal is removed or not installed (because I chose a
      non-Thai locale, and it is presumably only interesting to Thai
      language users) and doesn't appear in the menu
  or:
    - the Thai X Terminal is installed
    - commands can be run in it

Actual result
=============

* xiterm+thai is installed
* I see a bunch of messages in the terminal similar to:
  -bash: warning: setlocale: LC_CTYPE: cannot change locale (th_TH): No such file or directory
* when I press keys, no text appears at the prompt

Other information
=================

When I installed from the *GNOME* live image (which installs 
locales-all, not just locales), xiterm+thai does work. However, it 
doesn't seem practically useful to anyone who cannot read Thai: it 
appears to be hard-coded to set LANG=th_TH, so for example `grep --help` 
gives me help text partially translated into Thai.

If ordinary terminal emulators like gnome-terminal and LXTerminal are 
suitable for Thai-language users now that we have Unicode everywhere, 
then I'd suggest just using those terminals, rather than having a 
special Thai terminal preinstalled.

Or, if xiterm+thai is necessary for Thai-language users, then it's OK 
for it to be in the live image, but I think the live installation 
process should automatically remove it whenever it installs a system 
that is configured for a non-Thai language.

    smcv