Fix overwrite of existing cookiejar.

http.go

@@ -14,25 +14,18 @@ import (
 	"golang.org/x/net/html/atom"
 )
 
-// Get XFToken (data-csrf) from page html.
-func XFToken(page io.Reader) (string, error) {
-	z := html.NewTokenizer(page)
-	for i := z.Next(); i != html.ErrorToken; i = z.Next() {
-		tk := z.Token()
-		if tk.DataAtom == atom.Html {
-			for _, a := range tk.Attr {
-				switch a.Key {
-				case "data-csrf":
-					return a.Val, nil
-				}
-			}
+func getCookie(jar http.CookieJar, u *url.URL, name string) *http.Cookie {
+	cookies := jar.Cookies(u)
+	for _, c := range cookies {
+		if c.Name == name {
+			return c
 		}
 	}
 
-	return "", ErrNoXFToken
+	return nil
 }
 
-func setCookie(u *url.URL, jar http.CookieJar, newCookie *http.Cookie) {
+func setCookie(jar http.CookieJar, u *url.URL, newCookie *http.Cookie) {
 	cookies := jar.Cookies(u)
 
 	for i, c := range cookies {
@@ -48,6 +41,26 @@ func setCookie(u *url.URL, jar http.CookieJar, newCookie *http.Cookie) {
 	jar.SetCookies(u, cookies)
 }
 
+// Get XFToken (data-csrf) from page html.
+func XFToken(page io.Reader) (string, error) {
+	z := html.NewTokenizer(page)
+	for i := z.Next(); i != html.ErrorToken; i = z.Next() {
+		tk := z.Token()
+		if tk.DataAtom != atom.Html {
+			continue
+		}
+
+		for _, a := range tk.Attr {
+			switch a.Key {
+			case "data-csrf":
+				return a.Val, nil
+			}
+		}
+	}
+
+	return "", ErrNoXFToken
+}
+
 func (kf *KF) Do(req *http.Request) (*http.Response, error) {
 	var (
 		ctx = req.Context()