Case in available language keys is handled inconsistantly.

[jjabba]

Letter case in available language keys is sometimes ignored, behaviour is inconsistant.

When registering 'avaliable languages' such as (en_UK, de_DE) the letter case of the language returned when language is negotiated is inconsistant. It's sometimes en_UK, sometimes en_uk, depending on the way a match is found.

Your environment

• angular-translate - v2.15.2 - 2017-06-22
• AngularJS v1.6.6
• all browsers/environments

Steps to reproduce

Run the testcase supplied in pull request #1783 or look at this plunker https://plnkr.co/edit/5Eu5Qu0EXlBGd0ecigPg?p=preview

Expected behaviour

The language returned from $translate.use() should respect casing used when registering avaliable languages.

Actual behaviour

Depending on how matching is done in internal function 'negotiateLocale(preferred)', sometimes the letter case is respected, but sometimes not.

Fix

I've implemented a solution in pull request #1784 which passes the test in pull request #1783 and makes the returned language always respect case used when registering avaliable languages.

Why?!

The importance for this fix is more obvious if ngTranslate is used with the angular-translate-loader-static-files loader. Since the key/identifyer/language resolved by negotiateLocale() is used to determine which fileUrl is loaded, loading translations will fail if the server hosting the translations is case sensitive. This was how I originally found this bug.

[knalli]

@jjabba Thank you for all the great PRs! 🏎

I will have a look asap.

[jjabba]

@knalli Thanks for an awesome module, glad to try and make it even more awesome, my product is dependent on it.

[knalli]

Thank you very much for these contributions. Same as in #1789 :)