From d39aff8ecf0e4864207170db6387b186d06755ac Mon Sep 17 00:00:00 2001
From: Eric Chiang <eric.chiang.m@gmail.com>
Date: Wed, 2 Dec 2015 16:32:03 -0800
Subject: [PATCH] oauth2: don't fail if the token response does not expire

Some oauth2 implementations don't have an 'expires' or 'expires_in'
field, specifically GitHub. Don't fail if this happens.

Needed to use this package for coreos/dex#191
---
 oauth2/oauth2.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/oauth2/oauth2.go b/oauth2/oauth2.go
index 7d5c7316..3c641430 100644
--- a/oauth2/oauth2.go
+++ b/oauth2/oauth2.go
@@ -250,9 +250,11 @@ func parseTokenResponse(resp *http.Response) (result TokenResponse, err error) {
 		if e == "" {
 			e = vals.Get("expires")
 		}
-		result.Expires, err = strconv.Atoi(e)
-		if err != nil {
-			return
+		if e != "" {
+			result.Expires, err = strconv.Atoi(e)
+			if err != nil {
+				return
+			}
 		}
 	} else {
 		b := make(map[string]interface{})