Locale with upper case is resolved as used language but doesn't translate

With a upper-case locale i.e. en-GB and lower case registered languages/aliases/wildcard aliases the locale negotiation is done lower-case only, on a match however the uppercase input locale is used.

On translation the exact set locale (case sensitive) is used to determine the used dictionary and as the dictionary is defined with a the lower-case key the dictionary is not found and the fallback translation is used instead.

As far as I see it there are two possible solutions:

• On locale negotiation use the lower-case as the set locale
• Call angular.lowercase() on each translation when getting the translation dictionary

If you tell me the preferred solution I could create a PR.

[knalli]

I don’t get it. The locale negotiation behind the scenes (i.e. via determinePreferredLanguage()) is configurable with uniformLanguageTag(). However, if you apply a language explicitly, you are already in control. Where is the problem?

[ScallyGames]

I just realized that this is not as easy as first expected.

This would ensure not the requested but the actual used locale.

This is actually not the case - while this is true with language keys registered in lower case, it breaks on any other configuration (however this is not due to the proposed change but also in current production code)