Incorrect normalzation behaviour on character sequence '%e2%80%b3' #160
Description
Specifically, this produces an incorrect result:
1.9.3-p392 :019 > u = Addressable::URI.parse('http://example.org/%e2%80%b3')
=> #<Addressable::URI:0xd005e8 URI:http://example.org/%e2%80%b3>
1.9.3-p392 :020 > u.normalize!
=> #<Addressable::URI:0xd005e8 URI:http://example.org/%E2%80%B2%E2%80%B2>
Note that the normalized URL no longer matches.
I think this is related to Addressable::IDNA.unicode_normalize_kc
Specifiaclly:
1.9.3-p392 :013 > s = Addressable::URI.unencode('%e2%80%b3')
=> "″"
1.9.3-p392 :014 > Addressable::IDNA.unicode_normalize_kc(s)
=> "′′"
The output is now two UTF-8 characters, when previously it was one.