Expires-field in set cookie not parsed properly (=at all) by http package

[vdobler]

Parsing of the "expires" field in a set-cookie fails as
isCookieByte() of cookies.go will mark comma 0x2c and space 0x20
of the value of the expires field as invalid.
To my understanding the value of the expires field of a cookie
is a RFC1123 formatted time like "Sat, 21 May 2011 12:00:00 GMT"
which is allowed to contain spaces and commas without quoting them.
The issue is triggered by trying to validate values for fields
by calling parseCookieValue(val) which is too restrictive for 
expires.

What steps will reproduce the problem?
package main
import (
    "http"
    "fmt"
)

func main() {
    resp, _, _ := http.Get("http://www.google.ch";)
    fmt.Printf("%#v\n", resp.SetCookie[0].Unparsed)
}


What is the expected output?
"Nothing": []string{}

What do you see instead?
[]string{"expires=Sun, 19-May-2013 13:06:39 GMT"}

Which compiler are you using (5g, 6g, 8g, gccgo)?
8g

Which operating system are you using?
windows

Which revision are you using?  (hg identify)
r57.1

[rsc]

Comment 1:

I am pretty sure HTTP says , can be used to break lines.
But hey, who said HTTP was self-consistent?

Owner changed to @bradfitz.

Status changed to Accepted.

[bradfitz]

Comment 2:

Cookie is the HEAD method of HTTP Headers.

[bradfitz]

Comment 3:

http://golang.org/cl/4527073

[bradfitz]

Comment 4:

This issue was closed by revision 3933cb2.

Status changed to Fixed.