fix(change_detection): allow to destroy `OnPush` components inside of a host event.

Closes #7192

modules/angular2/src/core/change_detection/change_detection_jit_generator.ts

@@ -174,7 +174,7 @@ export class ChangeDetectorJITGenerator {
       var evalRecord = this._logic.genEventBindingEvalValue(eb, r);
       var markPath = this._genMarkPathToRootAsCheckOnce(r);
       var prevDefault = this._genUpdatePreventDefault(eb, r);
-      return `${evalRecord}\n${markPath}\n${prevDefault}`;
+      return `${markPath}\n${evalRecord}\n${prevDefault}`;
     } else {
       return this._logic.genEventBindingEvalValue(eb, r);
     }

modules/angular2/src/core/change_detection/dynamic_change_detector.ts

@@ -60,9 +60,11 @@ export class DynamicChangeDetector extends AbstractChangeDetector<any> {
       if (proto.isSkipRecord()) {
         protoIdx += this._computeSkipLength(protoIdx, proto, values);
       } else {
-        var res = this._calculateCurrValue(proto, values, locals);
         if (proto.lastInBinding) {
           this._markPathAsCheckOnce(proto);
+        }
+        var res = this._calculateCurrValue(proto, values, locals);
+        if (proto.lastInBinding) {
           return res;
         } else {
           this._writeSelf(proto, res, values);

modules/angular2/test/core/linker/integration_spec.ts

@@ -755,6 +755,30 @@ function declareTests() {
                             async.done();
                           })}));
 
+        if (DOM.supportsDOMEvents()) {
+          it("should allow to destroy a component from within a host event handler",
+             inject([TestComponentBuilder], fakeAsync((tcb: TestComponentBuilder) => {
+
+                      var fixture: ComponentFixture;
+                      tcb.overrideView(
+                             MyComp, new ViewMetadata({
+                               template: '<push-cmp-with-host-event></push-cmp-with-host-event>',
+                               directives: [[[PushCmpWithHostEvent]]]
+                             }))
+
+                          .createAsync(MyComp)
+                          .then(root => { fixture = root; });
+                      tick();
+                      fixture.detectChanges();
+
+                      var cmpEl = fixture.debugElement.children[0];
+                      var cmp: PushCmpWithHostEvent = cmpEl.inject(PushCmpWithHostEvent);
+                      cmp.ctxCallback = (_) => fixture.destroy();
+
+                      expect(() => cmpEl.triggerEventHandler('click', <Event>{})).not.toThrow();
+                    })));
+        }
+
         it('should not affect updating properties on the component',
            inject([TestComponentBuilder, AsyncTestCompleter],
                   (tcb: TestComponentBuilder, async) => {
@@ -1995,6 +2019,16 @@ class PushCmpWithRef {
   propagate() { this.ref.markForCheck(); }
 }
 
+@Component({
+  selector: 'push-cmp-with-host-event',
+  host: {'(click)': 'ctxCallback($event)'},
+  changeDetection: ChangeDetectionStrategy.OnPush,
+  template: ''
+})
+class PushCmpWithHostEvent {
+  ctxCallback: Function = (_) => {};
+}
+
 @Component({
   selector: 'push-cmp-with-async',
   changeDetection: ChangeDetectionStrategy.OnPush,

modules_dart/transform/lib/src/transform/template_compiler/change_detector_codegen.dart

@@ -253,7 +253,7 @@ class _CodegenState {
       var evalRecord = _logic.genEventBindingEvalValue(eb, r);
       var markPath = _genMarkPathToRootAsCheckOnce(r);
       var prevDefault = _genUpdatePreventDefault(eb, r);
-      return "${evalRecord}\n${markPath}\n${prevDefault}";
+      return "${markPath}\n${evalRecord}\n${prevDefault}";
     } else {
       return _logic.genEventBindingEvalValue(eb, r);
     }