fix($rootScope): ng-repeat can't handle NaN values. angular#4605

$watchCollection checks if oldValue !== newValue which does not work for NaN

Closes angular#4605

Author: SekibOmazic

src/ng/rootScope.js

@@ -448,7 +448,8 @@ function $RootScopeProvider(){
             }
             // copy the items to oldValue and look for changes.
             for (var i = 0; i < newLength; i++) {
-              if (oldValue[i] !== newValue[i]) {
+              var bothNaN = (oldValue[i] !== oldValue[i]) && (newValue[i] !== newValue[i]);
+              if (!bothNaN && (oldValue[i] !== newValue[i])) {
                 changeDetected++;
                 oldValue[i] = newValue[i];
               }

test/ng/rootScopeSpec.js

@@ -579,6 +579,13 @@ describe('Scope', function() {
           log = [];
           $rootScope.$digest();
           expect(log).toEqual([ '[{},[]]' ]);
+
+          log = [];
+          $rootScope.obj[0] = NaN;
+          $rootScope.$digest();
+          expect(isNaN(log.shift())).toBe(true); //jasmine's toBe and toEqual don't work well with NaNs
+          //expect(log).toEqual([ ]);
+
         });
 
         it('should watch array-like objects like arrays', function () {