Error on invalid URIs

[eraffel-MDSol]

If a URI is not valid, calling escape here:

rack-cache/lib/rack/cache/key.rb

Line 61 in 5261d91

parts.map! { |p| p.split('=', 2).map!{ |s| unescape(s) } }

can throw an argument error:
https://github.com/ruby/ruby/blob/e5a195edf62fe1bf7146a191da13fa1c4fecbd71/lib/uri/common.rb#L398

Wondering if rack-cache should handle this in some way rather than bubbling it up through the middleware, or if there's a suggestion on how applications should do so