🐛 Fixed redirect issue with private sites (#9960)

closes #9959

This issue existed because the logic assumed that if there were no
query parameters then there would be no `query` object. However this is
not the case. What we really wanted to check was for the existence of an
"r" query param - the code has been refactor to explicitly do this now.

core/server/apps/private-blogging/lib/middleware.js

@@ -29,7 +29,7 @@ function verifySessionHash(salt, hash) {
 }
 
 function getRedirectUrl(query) {
-    var redirect = decodeURIComponent(query ? query.r : '/');
+    var redirect = decodeURIComponent(query.r || '/');
     try {
         return url.parse(redirect, config.urlFor('home', true)).pathname;
     } catch (e) {

core/server/apps/private-blogging/tests/middleware_spec.js

@@ -34,7 +34,9 @@ describe('Private Blogging', function () {
         var req, res, next;
 
         beforeEach(function () {
-            req = {};
+            req = {
+                query: {}
+            };
             res = {};
             apiSettingsStub = sandbox.stub(api.settings, 'read');
             next = sinon.spy();