FIX: redirect to original URL after social signup

app/assets/javascripts/discourse/controllers/create-account.js.es6

@@ -205,6 +205,11 @@ export default Ember.Controller.extend(
           "accountChallenge"
         );
         const userFields = this.get("userFields");
+        const destinationUrl = this.get("authOptions.destination_url");
+
+        if (!Ember.isEmpty(destinationUrl)) {
+          $.cookie("destination_url", destinationUrl, { path: '/' });
+        }
 
         // Add the userfields to the data
         if (!Ember.isEmpty(userFields)) {
@@ -255,10 +260,12 @@ export default Ember.Controller.extend(
                 this.get("rejectedPasswords").pushObject(attrs.accountPassword);
               }
               this.set("formSubmitted", false);
+              $.cookie("destination_url", null);
             }
           },
           () => {
             this.set("formSubmitted", false);
+            $.cookie("destination_url", null);
             return this.flash(I18n.t("create_account.failed"), "error");
           }
         );

app/controllers/users_controller.rb

@@ -675,6 +675,8 @@ class UsersController < ApplicationController
     if current_user.present?
       if SiteSetting.enable_sso_provider && payload = cookies.delete(:sso_payload)
         return redirect_to(session_sso_provider_url + "?" + payload)
+      elsif destination_url = cookies.delete(:destination_url)
+        return redirect_to(destination_url)
       else
         return redirect_to(path('/'))
       end

lib/auth/result.rb

@@ -69,6 +69,8 @@ class Auth::Result
                  email_valid: !!email_valid,
                  omit_username: !!omit_username }
 
+      result[:destination_url] = destination_url if destination_url.present?
+
       if SiteSetting.enable_names?
         result[:name] = User.suggest_name(name || username || email)
       end

spec/requests/users_controller_spec.rb

@@ -2571,6 +2571,18 @@ describe UsersController do
       expect(response).to redirect_to("/")
     end
 
+    context 'when cookies contains a destination URL' do
+      it 'should redirect to the URL' do
+        sign_in(Fabricate(:user))
+        destination_url = 'http://thisisasite.com/somepath'
+        cookies[:destination_url] = destination_url
+
+        get "/u/account-created"
+
+        expect(response).to redirect_to(destination_url)
+      end
+    end
+
     context "when the user account is created" do
       include ApplicationHelper