[loc-en-dev] Locale Display Name with script

[Yoshito Umaoka]

Doug Felt wrote:
> The builder defaults language to 'und'
>
Hmmm..  I think I should clarify this..
Builder defaults language to empty string, but when you convert it to a 
language tag, "und" is used.  For example,

Locale loc = new Builder().setRegion("US").create();
String locStr = loc.toString();
String langtag = loc.toLanguageTag();


In this code,

locStr -> _US
langtag -> und-us

If we want to avoid this, one possible option is to mandate non-empty 
language in Builder#create().  But, we cannot use 
IllegalArgumentException here obviously!

-Yoshito