fix(ngModel): deregister from the form on scope not DOM destruction

Due to animations, DOM might get destroyed much later than scope and so the element $destroy event
might get fired outside of $digest, which causes changes to the validation model go unobserved
until the next digest. By deregistering on scope  event, the deregistration always happens
in $digest and the form validation model changes will be observed.

Closes #4226
Closes #4779

1 files changed, 1 insertions, 1 deletions

diff --git a/src/ng/directive/input.js b/src/ng/directive/input.js
index cc97411a..1c37167d 100644
--- a/src/ng/directive/input.js
+++ b/src/ng/directive/input.js
@@ -1222,7 +1222,7 @@ var ngModelDirective = function() {
 
       formCtrl.$addControl(modelCtrl);
 
-      element.on('$destroy', function() {
+      scope.$on('$destroy', function() {
         formCtrl.$removeControl(modelCtrl);
       });
     }