From 348ffd9a018f7c6f268b632afaca4ef6d9671c7c Mon Sep 17 00:00:00 2001
From: silky <noonsilk+github@gmail.com>
Date: Tue, 13 Oct 2015 15:22:57 +1100
Subject: [PATCH] Fixes #42; slightly nicer error message when no 'code' field.

---
 Yesod/Auth/OAuth2.hs    | 21 ++++++++++++---------
 yesod-auth-oauth2.cabal |  4 ++--
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/Yesod/Auth/OAuth2.hs b/Yesod/Auth/OAuth2.hs
index 7a9145d..0c2b6a8 100644
--- a/Yesod/Auth/OAuth2.hs
+++ b/Yesod/Auth/OAuth2.hs
@@ -102,15 +102,18 @@ authOAuth2Widget widget name oauth getCreds = AuthPlugin name dispatch login
         deleteSession tokenSessionKey
         case newToken of
             Just csrfToken | newToken == oldToken -> do
-                code <- lift $ runInputGet $ ireq textField "code"
-                oauth' <- withCallback csrfToken
-                master <- lift getYesod
-                result <- liftIO $ fetchAccessToken (authHttpManager master) oauth' (encodeUtf8 code)
-                case result of
-                    Left _ -> permissionDenied "Unable to retreive OAuth2 token"
-                    Right token -> do
-                        creds <- liftIO $ getCreds (authHttpManager master) token
-                        lift $ setCredsRedirect creds
+                mcode <- lift $ runInputGet $ iopt textField "code"
+                case mcode of
+                     Nothing -> permissionDenied "`Code` field not provided."
+                     Just code -> do
+                        oauth' <- withCallback csrfToken
+                        master <- lift getYesod
+                        result <- liftIO $ fetchAccessToken (authHttpManager master) oauth' (encodeUtf8 code)
+                        case result of
+                            Left _ -> permissionDenied "Unable to retreive OAuth2 token"
+                            Right token -> do
+                                creds <- liftIO $ getCreds (authHttpManager master) token
+                                lift $ setCredsRedirect creds
             _ ->
                 permissionDenied "Invalid OAuth2 state token"
 
diff --git a/yesod-auth-oauth2.cabal b/yesod-auth-oauth2.cabal
index 7c25d80..c740627 100644
--- a/yesod-auth-oauth2.cabal
+++ b/yesod-auth-oauth2.cabal
@@ -1,5 +1,5 @@
 name:            yesod-auth-oauth2
-version:         0.1.4
+version:         0.1.5
 license:         BSD3
 license-file:    LICENSE
 author:          Tom Streller
@@ -52,4 +52,4 @@ library
 
 source-repository head
   type:     git
-  location: https://github.com/thoughtbot/authenticate-oauth2.git
+  location: https://github.com/thoughtbot/yesod-auth-oauth2.git