Bug 456050

SUMMARY
***
STEPS TO REPRODUCE
1. Go to System Settings --> Personalization --> Regional Settings --> Language
2. Add on top of "American English (default)" the language "Nederlands". Put "Nederlands" at the bottom.
3. Save, reboot, run plasma/kde
4. On konsole prompt type an error (for example:  sudo foobar). It will report
an error in Dutch.  The direct reason for seeing Dutch is (apparently) due to
the environment variable LANGUAGE which is set to "en_US:nl".  Changing that
into "nl:en_US" doesn't make a difference: still dutch error messages.
Only when changing LANGUAGE into "en_US" you get English error messages.


OBSERVED RESULT


EXPECTED RESULT
Everything is still 100% English (en_US), but now spelling checking also works when I type in Dutch.


ADDITIONAL INFORMATION

There is another bug; if you choose in the list of Formats (not Language) en_NL - then everything breaks because that locale doesn't exist and is not supported. I think it SHOULD be supported: everyone in the Netherlands speaks English - this basically a two-language country, one of them being English. Aka  en_NL makes a LOT of sense, exactly like all the other en_XY locales. Nevertheless, if I select it, then I expect it to work - and it doesn't: you can't generate that locale because certain idiots think it is not needed and refuse to add it (see for example https://sourceware.org/bugzilla/show_bug.cgi?id=14085)