Value of Content-Disposition header:

Content-Disposition: attachment; filename*=UTF-8''foo-a%cc%88.html

Test Description:

'attachment', specifying a filename of foo-.html, using RFC2231 encoded UTF-8, but choosing the decomposed form (lowercase a plus COMBINING DIAERESIS) -- on a Windows target system, this should be translated to the preferred Unicode normal form (composed).

UA should offer to download the resource as "foo-.html".