fix($compile): ensure isolated local watches lastValue is always in syn...

src/ng/compile.js

@@ -1444,7 +1444,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
                       parentSet(scope, parentValue = lastValue = isolateScope[scopeName]);
                     }
                   }
-                  return parentValue;
+                  return lastValue = parentValue;
                 });
                 break;
 

test/ng/compileSpec.js

@@ -2386,6 +2386,24 @@ describe('$compile', function() {
         expect(componentScope.refAlias).toBe($rootScope.name);
       }));
 
+      it('should not break if local and origin both change to the same value', inject(function() {
+        $rootScope.name = 'aaa';
+
+        compile('<div><span my-component ref="name">');
+
+        //change both sides to the same item withing the same digest cycle
+        componentScope.ref = 'same';
+        $rootScope.name = 'same';
+        $rootScope.$apply();
+
+        //change origin back to it's previous value
+        $rootScope.name = 'aaa';
+        $rootScope.$apply();
+
+        expect($rootScope.name).toBe('aaa');
+        expect(componentScope.ref).toBe('aaa');
+      }));
+
       it('should complain on non assignable changes', inject(function() {
         compile('<div><span my-component ref="\'hello \' + name">');
         $rootScope.name = 'world';