http: fix Set-Cookie date parsing

Fixes #1855

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4527073

src/pkg/http/cookie.go

@@ -81,12 +81,17 @@ func readSetCookies(h Header) []*Cookie {
 			if j := strings.Index(attr, "="); j >= 0 {
 				attr, val = attr[:j], attr[j+1:]
 			}
-			val, success = parseCookieValue(val)
+			lowerAttr := strings.ToLower(attr)
+			parseCookieValueFn := parseCookieValue
+			if lowerAttr == "expires" {
+				parseCookieValueFn = parseCookieExpiresValue
+			}
+			val, success = parseCookieValueFn(val)
 			if !success {
 				c.Unparsed = append(c.Unparsed, parts[i])
 				continue
 			}
-			switch strings.ToLower(attr) {
+			switch lowerAttr {
 			case "secure":
 				c.Secure = true
 				continue
@@ -112,8 +117,11 @@ func readSetCookies(h Header) []*Cookie {
 				c.RawExpires = val
 				exptime, err := time.Parse(time.RFC1123, val)
 				if err != nil {
-					c.Expires = time.Time{}
-					break
+					exptime, err = time.Parse("Mon, 02-Jan-2006 15:04:05 MST", val)
+					if err != nil {
+						c.Expires = time.Time{}
+						break
+					}
 				}
 				c.Expires = *exptime
 				continue
@@ -272,7 +280,7 @@ func unquoteCookieValue(v string) string {
 }
 
 func isCookieByte(c byte) bool {
-	switch true {
+	switch {
 	case c == 0x21, 0x23 <= c && c <= 0x2b, 0x2d <= c && c <= 0x3a,
 		0x3c <= c && c <= 0x5b, 0x5d <= c && c <= 0x7e:
 		return true
@@ -280,10 +288,22 @@ func isCookieByte(c byte) bool {
 	return false
 }
 
+func isCookieExpiresByte(c byte) (ok bool) {
+	return isCookieByte(c) || c == ',' || c == ' '
+}
+
 func parseCookieValue(raw string) (string, bool) {
+	return parseCookieValueUsing(raw, isCookieByte)
+}
+
+func parseCookieExpiresValue(raw string) (string, bool) {
+	return parseCookieValueUsing(raw, isCookieExpiresByte)
+}
+
+func parseCookieValueUsing(raw string, validByte func(byte) bool) (string, bool) {
 	raw = unquoteCookieValue(raw)
 	for i := 0; i < len(raw); i++ {
-		if !isCookieByte(raw[i]) {
+		if !validByte(raw[i]) {
 			return "", false
 		}
 	}

src/pkg/http/cookie_test.go

@@ -11,9 +11,9 @@ import (
 	"os"
 	"reflect"
 	"testing"
+	"time"
 )
 
-
 var writeSetCookiesTests = []struct {
 	Cookies []*Cookie
 	Raw     string
@@ -115,6 +115,19 @@ var readSetCookiesTests = []struct {
 		Header{"Set-Cookie": {"Cookie-1=v$1"}},
 		[]*Cookie{&Cookie{Name: "Cookie-1", Value: "v$1", Raw: "Cookie-1=v$1"}},
 	},
+	{
+		Header{"Set-Cookie": {"NID=99=YsDT5i3E-CXax-; expires=Wed, 23-Nov-2011 01:05:03 GMT; path=/; domain=.google.ch; HttpOnly"}},
+		[]*Cookie{&Cookie{
+			Name:       "NID",
+			Value:      "99=YsDT5i3E-CXax-",
+			Path:       "/",
+			Domain:     ".google.ch",
+			HttpOnly:   true,
+			Expires:    time.Time{Year: 2011, Month: 11, Day: 23, Hour: 1, Minute: 5, Second: 3, Weekday: 3, ZoneOffset: 0, Zone: "GMT"},
+			RawExpires: "Wed, 23-Nov-2011 01:05:03 GMT",
+			Raw:        "NID=99=YsDT5i3E-CXax-; expires=Wed, 23-Nov-2011 01:05:03 GMT; path=/; domain=.google.ch; HttpOnly",
+		}},
+	},
 }
 
 func toJSON(v interface{}) string {