From 88e11acd3f399031bd0a8966e5495c2d3af77618 Mon Sep 17 00:00:00 2001
From: Sebastian Wilzbach <seb@wilzba.ch>
Date: Sun, 4 Jun 2017 01:40:16 +0200
Subject: [PATCH 1/2] login(): indicate current state (present session vs.
 redirect)

---
 source/oauth/webapp.d | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/source/oauth/webapp.d b/source/oauth/webapp.d
index a58dbcd..79bb2da 100644
--- a/source/oauth/webapp.d
+++ b/source/oauth/webapp.d
@@ -82,8 +82,11 @@ class OAuthWebapp
             settings = The OAuth settings that apply to this _login attempt
             scopes = (Optional) An array of identifiers specifying the scope of
                 the authorization requested.
+        Returns: `true` if a OAuth session was obtained and
+                 `false` if no OAuth session is present and a redirect to an
+                  OAuth provider will happen.
       +/
-    void login(
+    bool login(
         scope HTTPServerRequest req,
         scope HTTPServerResponse res,
         immutable OAuthSettings settings,
@@ -100,6 +103,8 @@ class OAuthWebapp
 
             auto session = settings.userSession(
                 req.session, req.query["state"], req.query["code"]);
+
+            return true;
         }
         else
         {
@@ -107,17 +112,18 @@ class OAuthWebapp
                 req.session = res.startSession();
 
             res.redirect(settings.userAuthUri(req.session, extraParams, scopes));
+            return false;
         }
     }
 
     /// ditto
-    void login(
+    bool login(
         scope HTTPServerRequest req,
         scope HTTPServerResponse res,
         immutable OAuthSettings settings,
         in string[] scopes) @safe
     {
-        login(req, res, settings, null, scopes);
+        return login(req, res, settings, null, scopes);
     }
 
     /++

From f257fcd9a8f63956870376fdf89f56282a840736 Mon Sep 17 00:00:00 2001
From: Sebastian Wilzbach <seb@wilzba.ch>
Date: Sun, 4 Jun 2017 01:40:49 +0200
Subject: [PATCH 2/2] Make sure that a session is properly initialized and
 added to req.context

---
 source/oauth/webapp.d | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/source/oauth/webapp.d b/source/oauth/webapp.d
index 79bb2da..5eddd6a 100644
--- a/source/oauth/webapp.d
+++ b/source/oauth/webapp.d
@@ -25,6 +25,19 @@ class OAuthWebapp
 {
     version (Have_vibe_d_web) @noRoute:
 
+    private OAuthSession loadSessionToContext(scope HTTPServerRequest req, immutable OAuthSettings settings) @safe
+    in {
+        assert(settings !is null, "Settings can't be null");
+    }
+    body
+    {
+        auto session = OAuthSession.load(settings, req.session);
+        () @trusted {
+            req.context["oauth.session"] = session;
+        } ();
+        return session;
+    }
+
     /++
         Check if a request is from a logged in user
 
@@ -49,13 +62,9 @@ class OAuthWebapp
         if (!req.session)
             return false;
 
-        if (auto session =
-            settings ? OAuthSession.load(settings, req.session) : null)
+        if (settings !is null)
         {
-            () @trusted {
-                req.context["oauth.session"] = session;
-            } ();
-
+            loadSessionToContext(req, settings);
             return true;
         }
 
@@ -137,12 +146,13 @@ class OAuthWebapp
 
         Params:
             req = the request to get the relevant session for
+            settings = The OAuth settings that apply to this _login attempt
 
         Returns: The session associated to req, or `null` if no
             session was found.
       +/
     final
-    OAuthSession oauthSession(scope HTTPServerRequest req) nothrow @trusted
+    OAuthSession oauthSession(scope HTTPServerRequest req, immutable OAuthSettings settings = null) nothrow @trusted
     in
     {
         try
@@ -153,15 +163,18 @@ class OAuthWebapp
     body
     {
         try
+        {
             if (auto pCM = "oauth.session" in req.context)
                 return pCM.get!OAuthSession;
+            else
+                return loadSessionToContext(req, settings);
+        }
         catch (Exception e)
         {
             import vibe.core.log : logError;
             logError("OAuth: Exception occurred while reading request " ~
                 "context: %s", e.toString());
         }
-
         return null;
     }
 }