gtk+-1.2.10 locale problem though libc and xlib accept locale

[i7tiol t-online de (Olaf Till)]

Hi,

I am typing in text in gtk+ versions 1.2.8 to 1.2.10 (compiled with
the default configuration). I am using libc6-2.1.3-20 and XFree86
4.2.0 on Debian GNU/Linux 2.2.

When LANG is a locale with something after the point `.',
e.g. en_GB.ISO8859-1 instead of en_GB, any non-ASCII characters typed
in are not displayed.

The locales do exist on the system. Even when I replace the
en_GB.ISO8859-1 locale with a copy of en_GB renamed to
en_GB.ISO8859-1, there is the same problem, although en_GB works
without this problem.

The tests in gdkim.c

  if (!setlocale (LC_ALL,""))
    g_warning ("locale not supported by C library");
  
  if (!XSupportsLocale ())
    {
      g_warning ("locale not supported by Xlib, locale set to C");
      setlocale (LC_ALL, "C");
    }
  
  if (!XSetLocaleModifiers (""))
    g_warning ("can not set locale modifiers");

are passed with no warnings (tested with a debugger).

X-Toolkit applications do not have this problem, also the xev program
displays the non-ASCII characters.

I do not think it matters, since en_GB works, but my
/usr/local/etc/gtk/gtkrc is a symlink to a file with the contents:

style "gtk-default-iso-8859-15" {
       fontset = "-*-helvetica-medium-r-normal--12-*-*-*-*-*-iso8859-1,\
                  -*-arial-medium-r-normal--12-*-*-*-*-*-iso8859-1,\
		  -*-helvetica-medium-r-normal--12-*-*-*-*-*-iso8859-15,\
		  -*-arial-medium-r-normal--12-*-*-*-*-*-iso8859-15,*-r-*"
}
class "GtkWidget" style "gtk-default-iso-8859-15"

Most puzzling, it did work on my system some time ago. The change
which broke it must be outside gtk, but I can not reproduce it. Where
have I to search for it? What does gtk-1.2.10 actually do when
characters are typed into an entry widget -- probably relying on Xlib,
but why then does it work with X-Toolkit applications?

Any ideas are much appreciated.

Olaf

If possible, CC any answers to me: i7tiol t-online de   --- thanks.