Missing charset leads to error in the frontend

[rcheetah]

My mail did no have the charset set to 'utf-8'. When the subject contains a character such as an umlaut or typographic Quotes („““), then the whole subject will not but display, but instead this internal code:

{{ tryDecodeMime(preview.Content.Headers["Subject"][0]) }}

This feels like a bug!? The frontend should not display this. Normally the string should be displayed, and only the non-ASCII characters should be displayed weirdly, right?

Also mind the console error:

angular-1.3.8.js:11594 ReferenceError: ISO88591_MAP_ENCODED is not defined
    at maybeInitIso88591Maps (strutil.js:392:17)
    at convertIso88591BytesToUnicodeCodePoints (strutil.js:487:3)
    at convertBytesToUnicodeCodePoints (strutil.js:727:12)
    at unescapeFromMime (strutil.js:985:27)
    at ChildScope.$scope.tryDecodeMime (controllers.js:185:12)
    at $parseFunctionCall (angular-1.3.8.js:12332:18)
    at Object.expressionInputWatch (angular-1.3.8.js:12735:31)
    at Scope.$digest (angular-1.3.8.js:14217:40)
    at Scope.$apply (angular-1.3.8.js:14488:24)
    at angular-1.3.8.js:16214:36