Comment 1 for bug 285491

This sort of thing is a serious problem. You have to use a locale aware (or more to the point, a locale-ignoring) case conversion function.

We ran into something like this in java-gnome. See http://bugzilla.gnome.org/show_bug.cgi?id=529052#c5 and java-gnome 'mainline' revno 491 where we explicitly forced English as the locale rules. [some conversion transparently use the active locale, and so internals that assume that i will transform into I and vice versa will break for people in Turkish locales]

AfC