fix(forms): Propagate change from model even if it's undefined

src/directive/input.js

@@ -847,7 +847,7 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', 'ngModel',
       value = formatters[idx](value);
     }
 
-    if (isDefined(value) && ctrl.viewValue !== value) {
+    if (ctrl.viewValue !== value) {
       ctrl.viewValue = value;
       ctrl.render();
     }
@@ -1042,7 +1042,7 @@ var requiredDirective = [function() {
       if (!ctrl) return;
 
       var validator = function(value) {
-        if (attr.required && isEmpty(value)) {
+        if (attr.required && (isEmpty(value) || value === false)) {
           ctrl.setValidity('REQUIRED', false);
           return null;
         } else {

test/directive/inputSpec.js

@@ -183,22 +183,32 @@ describe('NgModelController', function() {
     });
 
 
-    it('should $render only if value changed and is valid', function() {
+    it('should $render only if value changed', function() {
       spyOn(ctrl, 'render');
 
       scope.$apply(function() {
-        scope.value= 3;
+        scope.value = 3;
       });
       expect(ctrl.render).toHaveBeenCalledOnce();
       ctrl.render.reset();
 
-      // invalid
-      ctrl.formatters.push(function() {return undefined;});
+      ctrl.formatters.push(function() {return 3;});
       scope.$apply(function() {
-        scope.value= 5;
+        scope.value = 5;
       });
       expect(ctrl.render).not.toHaveBeenCalled();
     });
+
+
+    it('should clear the view even if invalid', function() {
+      spyOn(ctrl, 'render');
+
+      ctrl.formatters.push(function() {return undefined;});
+      scope.$apply(function() {
+        scope.value = 5;
+      });
+      expect(ctrl.render).toHaveBeenCalledOnce();
+    });
   });
 });
 
@@ -729,6 +739,19 @@ describe('input', function() {
       browserTrigger(inputElm, 'click');
       expect(scope.name).toEqual('n');
     });
+
+
+    it('should be required if false', function() {
+      compileInput('<input type="checkbox" ng:model="value" required />');
+
+      browserTrigger(inputElm, 'click');
+      expect(inputElm[0].checked).toBe(true);
+      expect(inputElm).toBeValid();
+
+      browserTrigger(inputElm, 'click');
+      expect(inputElm[0].checked).toBe(false);
+      expect(inputElm).toBeInvalid();
+    });
   });