Strip unused modifiers from URLs with Change IDs

This change replicates the behavior of the GWTUI that stripped the n,z
modifier from change URLs, as seen in http://goo.gl/timWzy

Links from Gitiles still contain these modifiers, but they are not
supported by the backend.

Also includes a small change left over from c/85964 to ensure that no
API calls are made during automated testing.

Bug: Issue 4524
Change-Id: Ib58fb5347b39611a83708cf53a2a75bee454171e

polygerrit-ui/app/elements/change/gr-message/gr-message_test.html

@@ -37,6 +37,7 @@ limitations under the License.
 
     setup(function() {
       element = fixture('basic');
+      sinon.stub(element.$.restAPI, 'getLoggedIn').returns(true);
     });
 
     test('reply event', function(done) {

polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js

@@ -94,7 +94,6 @@
     fetchJSON: function(url, opt_errFn, opt_cancelCondition, opt_params,
         opt_opts) {
       opt_opts = opt_opts || {};
-
       var fetchOptions = {
         credentials: 'same-origin',
         headers: opt_opts.headers,
@@ -312,6 +311,10 @@
           ListChangesOption.LABELS,
           ListChangesOption.DETAILED_ACCOUNTS
       );
+      // Issue 4524: respect legacy token with max sortkey.
+      if (opt_offset === 'n,z') {
+        opt_offset = 0;
+      }
       var params = {
         n: changesPerPage,
         O: options,

polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html

@@ -324,5 +324,11 @@ limitations under the License.
         });
       });
     });
+
+    test('legacy n,z key in change url is replaced', function() {
+      var stub = sandbox.stub(element, 'fetchJSON');
+      element.getChanges(1, null, 'n,z');
+      assert.equal(stub.args[0][3].S, 0);
+    });
   });
 </script>