when jasmine clock is installed and date is mocked new Date() instanceof Date should equal true

spec/core/ClockSpec.js

@@ -417,6 +417,8 @@ describe("Clock (acceptance)", function() {
 
     clock.install().mockDate();
 
+    expect(new global.Date() instanceof global.Date).toBe(true);
+
     var now = new global.Date().getTime();
 
     clock.tick(50);
@@ -443,6 +445,8 @@ describe("Clock (acceptance)", function() {
 
     clock.install().mockDate(baseTime);
 
+    expect(new global.Date() instanceof global.Date).toBe(true);
+
     var now = new global.Date().getTime();
 
     expect(now).toEqual(baseTime.getTime());

src/core/MockDate.js

@@ -61,6 +61,7 @@ getJasmineRequireObj().MockDate = function() {
     }
 
     function createDateProperties() {
+      FakeDate.prototype = GlobalDate.prototype;
 
       FakeDate.now = function() {
         if (GlobalDate.now) {