DOM URL pathname setter double encodes entities

[Joshua Peek]

Created attachment 244139 [details]
URL pathname test

The URL pathname setter incorrectly re-encodes the target value before setting it as the pathname attribute. The getter always correctly returns the undecoded pathname.

  var url = new URL("http://example.com/")
  url.pathname = "foo%20bar"
  url.pathname // "/foo%2520bar"
  url.href // "http://example.com/foo%2520bar"

This breaks the ability to reset pathname with the value from its getter.

  var url = new URL("http://example.com/foo%20bar")
  url.pathname // "/foo%20bar"
  url.pathname = url.pathname + "/123"
  url.pathname // "/foo%2520bar/123"

I don't think the pathname setter is correctly performing the "Basic URL parse" step in https://url.spec.whatwg.org/#dom-urlutils-pathname

[Rob Buis]

This is fixed these days.