[gtkada] Locale_To_UTF8 problem

[Arnaud Charlet]

> The function
> Locale_To_UTF8 (OS_String : String) return String in
> package Glib.Convert raises the exception 
> Interfaces.C.Strings.Dereference_Error when the
> input string contains a non-ascii Latin-1 character.

It will now return an empty string instead, which is closer to the
C approach.

> This happens on a number of Linux systems when the
> value of LANG=C for example.

We have observed that Locale_To_UTF* was not working reliably
unless you set the CHARSET env variable as well. It's probably
a glib bug, but we've never traced down the exact cause of the problem
to report it to the glib maintainers.

(And happy new year to all the people reading this list).

Arno