1
ruri := r.URL.RequestURI()
2
if usingProxy && r.URL.Scheme != "" && r.URL.Opaque == "" {
3
  ruri = r.URL.Scheme + "://" + host + ruri
4
} else if r.Method == "CONNECT" && r.URL.Path == "" {
5
  // CONNECT requests normally give just the host and port, not a full URL.
6
  ruri = host
7
  if r.URL.Opaque != "" {
8
    ruri = r.URL.Opaque
9
  }
10
}
11
if stringContainsCTLByte(ruri) {
12
  return errors.New("net/http: can't write control character in Request.URL")
13
}

1
// stringContainsCTLByte reports whether s contains any ASCII control character.
2
func stringContainsCTLByte(s string) bool {
3
  for i := 0; i < len(s); i++ {
4
    b := s[i]
5
    if b < ' ' || b == 0x7f {
6
      return true
7
    }
8
  }
9
  return false
10
}