Value of Content-Disposition header:
Content-Disposition: attachment; name="foo-%41.html"
Test Description:
'attachment', specifying a name parameter of foo-%41.html
.
(this test was added to observe the behavior of the (unspecified) treatment of "name" as
synonym for "filename"; see Ned Freed's summary
where this comes from in MIME messages)
Should be treated as extension parameter, therefore almost any behavior is acceptable.