fix(dynamic_component_loader): leave the view tree in a consistent state when hydration fails

Closes #5718

modules/angular2/src/core/application_ref.ts

@@ -1,5 +1,12 @@
 import {NgZone} from 'angular2/src/core/zone/ng_zone';
-import {Type, isBlank, isPresent, assertionsEnabled, print, IS_DART} from 'angular2/src/facade/lang';
+import {
+  Type,
+  isBlank,
+  isPresent,
+  assertionsEnabled,
+  print,
+  IS_DART
+} from 'angular2/src/facade/lang';
 import {provide, Provider, Injector, OpaqueToken} from 'angular2/src/core/di';
 import {
   APP_COMPONENT_REF_PROMISE,

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

@@ -169,7 +169,7 @@ export class AbstractChangeDetector<T> implements ChangeDetector {
   // any work done in `hydrateDirectives`.
   dehydrateDirectives(destroyPipes: boolean): void {}
 
-  hydrated(): boolean { return this.context !== null; }
+  hydrated(): boolean { return isPresent(this.context); }
 
   afterContentLifecycleCallbacks(): void {
     this.dispatcher.notifyAfterContentChecked();

modules/angular2/src/core/linker/view_manager.ts

@@ -319,9 +319,15 @@ export class AppViewManager_ extends AppViewManager {
     }
     this._utils.attachViewInContainer(parentView, boundElementIndex, contextView,
                                       contextBoundElementIndex, index, view);
-    this._utils.hydrateViewInContainer(parentView, boundElementIndex, contextView,
-                                       contextBoundElementIndex, index,
-                                       imperativelyCreatedInjector);
+
+    try {
+      this._utils.hydrateViewInContainer(parentView, boundElementIndex, contextView,
+                                         contextBoundElementIndex, index,
+                                         imperativelyCreatedInjector);
+    } catch (e) {
+      this._utils.detachViewInContainer(parentView, boundElementIndex, index);
+      throw e;
+    }
     return view.ref;
   }