Add the feature that callback_url could begin with /.

lib/sorcery/controller/submodules/external.rb

@@ -33,6 +33,14 @@ module InstanceMethods
           # after authentication the user is redirected to the callback defined in the provider config
           def login_at(provider, args = {})
             @provider = Config.send(provider)
+            if @provider.callback_url.present? && @provider.callback_url[0] == '/'
+              uri = URI.parse(request.url.gsub(/\?.*$/,''))
+              uri.path = ''
+              uri.query = nil
+              uri.scheme = 'https' if(request.env['HTTP_X_FORWARDED_PROTO'] == 'https')
+              host = uri.to_s
+              @provider.callback_url = "#{host}#{@provider.callback_url}"
+            end
             if @provider.has_callback?
               redirect_to @provider.login_url(params,session)
             else

spec/rails3/spec/controller_oauth2_spec.rb

@@ -64,13 +64,30 @@ def set_external_property
       Authentication.delete_all
     end
 
-    it "login_at redirects correctly" do
-      create_new_user
-      get :login_at_test2
-      response.should be_a_redirect
-      response.should redirect_to("https://graph.facebook.com/oauth/authorize?response_type=code&client_id=#{::Sorcery::Controller::Config.facebook.key}&redirect_uri=http%3A%2F%2Fblabla.com&scope=email%2Coffline_access&display=page")
+    context "when callback_url begin with /" do 
+      before do
+        sorcery_controller_external_property_set(:facebook, :callback_url, "/oauth/twitter/callback")
+      end
+      it "login_at redirects correctly" do
+        create_new_user
+        get :login_at_test2
+        response.should be_a_redirect
+        response.should redirect_to("https://graph.facebook.com/oauth/authorize?response_type=code&client_id=#{::Sorcery::Controller::Config.facebook.key}&redirect_uri=http%3A%2F%2Ftest.host%2Foauth%2Ftwitter%2Fcallback&scope=email%2Coffline_access&display=page")
+      end
+      after do
+        sorcery_controller_external_property_set(:facebook, :callback_url, "http://blabla.com")
+      end
     end
 
+    context "when callback_url begin with http://" do 
+      it "login_at redirects correctly" do
+        create_new_user
+        get :login_at_test2
+        response.should be_a_redirect
+        response.should redirect_to("https://graph.facebook.com/oauth/authorize?response_type=code&client_id=#{::Sorcery::Controller::Config.facebook.key}&redirect_uri=http%3A%2F%2Fblabla.com&scope=email%2Coffline_access&display=page")
+      end
+    end
+
     it "'login_from' logins if user exists" do
       sorcery_model_property_set(:authentications_class, Authentication)
       create_new_external_user(:facebook)

spec/rails3/spec/controller_oauth_spec.rb

@@ -43,11 +43,28 @@ def stub_all_oauth_requests!
       Authentication.delete_all
     end
 
-    it "login_at redirects correctly" do
-      create_new_user
-      get :login_at_test
-      response.should be_a_redirect
-      response.should redirect_to("http://myapi.com/oauth/authorize?oauth_callback=http%3A%2F%2Fblabla.com&oauth_token=")
+    context "when callback_url begin with /" do 
+      before do
+        sorcery_controller_external_property_set(:twitter, :callback_url, "/oauth/twitter/callback")
+      end
+      it "login_at redirects correctly" do
+        create_new_user
+        get :login_at_test
+        response.should be_a_redirect
+        response.should redirect_to("http://myapi.com/oauth/authorize?oauth_callback=http%3A%2F%2Ftest.host%2Foauth%2Ftwitter%2Fcallback&oauth_token=")
+      end
+      after do
+        sorcery_controller_external_property_set(:twitter, :callback_url, "http://blabla.com")
+      end
+    end
+
+    context "when callback_url begin with http://" do 
+      it "login_at redirects correctly" do
+        create_new_user
+        get :login_at_test
+        response.should be_a_redirect
+        response.should redirect_to("http://myapi.com/oauth/authorize?oauth_callback=http%3A%2F%2Fblabla.com&oauth_token=")
+      end
     end
 
     it "logins if user exists" do