fix(ngEventDirs): don't wrap the event handler in $apply if already in $digest

Digest cycle already in progress error can inadvertently be caused when triggering an
element's click event while within an active digest cycle. This is due to the ngEventsDirs
event handler always calling $rootScope.$apply regardless of the status of $rootScope.$$phase.
Checking the phase and calling the function immediately if within an active digest cycle
will prevent the problem without reducing current functionality.

Closes #14673
Closes #14674

Author: markgardner

src/ng/directive/ngEventDirs.js

@@ -64,10 +64,12 @@ forEach(
               var callback = function() {
                 fn(scope, {$event: event});
               };
-              if (forceAsyncEvents[eventName] && $rootScope.$$phase) {
+              if (!$rootScope.$$phase) {
+                scope.$apply(callback);
+              } else if (forceAsyncEvents[eventName]) {
                 scope.$evalAsync(callback);
               } else {
-                scope.$apply(callback);
+                callback();
               }
             });
           };

test/ng/directive/ngEventDirsSpec.js

@@ -150,4 +150,44 @@ describe('event directives', function() {
     }));
 
   });
+
+
+  it('should call the listener synchronously if the event is triggered inside of a digest',
+      inject(function($rootScope, $compile) {
+    var watchedVal;
+
+    element = $compile('<button type="button" ng-click="click()">Button</button>')($rootScope);
+    $rootScope.$watch('value', function(newValue) {
+      watchedVal = newValue;
+    });
+    $rootScope.click = jasmine.createSpy('click').and.callFake(function() {
+      $rootScope.value = 'newValue';
+    });
+
+    $rootScope.$apply(function() {
+      element.triggerHandler('click');
+    });
+
+    expect($rootScope.click).toHaveBeenCalledOnce();
+    expect(watchedVal).toEqual('newValue');
+  }));
+
+
+  it('should call the listener synchronously if the event is triggered outside of a digest',
+      inject(function($rootScope, $compile) {
+    var watchedVal;
+
+    element = $compile('<button type="button" ng-click="click()">Button</button>')($rootScope);
+    $rootScope.$watch('value', function(newValue) {
+      watchedVal = newValue;
+    });
+    $rootScope.click = jasmine.createSpy('click').and.callFake(function() {
+      $rootScope.value = 'newValue';
+    });
+
+    element.triggerHandler('click');
+
+    expect($rootScope.click).toHaveBeenCalledOnce();
+    expect(watchedVal).toEqual('newValue');
+  }));
 });