According to my understanding of RFC 822, the following is encoded correctly: Content-Disposition: attachment;filename="foo\" \"bar.html" The decoded value for the filename attribute should be: foo" "bar.html But instead it is decoded as: foo\" \"bar.html Firefox an Opera both get it right.
File names in Content-Disposition are handled not by open source WebKit, but by Apple system frameworks. Could you please file this bug at http://bugreport.apple.com instead? If not, someone else can do it, but it is better when a bug is linked to its original reporter.