fix(ProtoView): element injector should have either a parent or a host

fix #359

modules/core/src/compiler/pipeline/proto_element_injector_builder.js

@@ -49,13 +49,10 @@ export class ProtoElementInjectorBuilder extends CompileStep {
   }
 
   _getParentProtoElementInjector(parent, current) {
-    var parentProtoElementInjector = null;
-    if (current.isViewRoot) {
-      parentProtoElementInjector = null;
-    } else if (isPresent(parent)) {
-      parentProtoElementInjector = parent.inheritedProtoElementInjector;
+    if (isPresent(parent) && !current.isViewRoot) {
+      return parent.inheritedProtoElementInjector;
     }
-    return parentProtoElementInjector;
+    return null;
   }
 
   _collectDirectiveBindings(pipelineElement) {

modules/core/src/compiler/view.js

@@ -309,9 +309,11 @@ export class ProtoView {
       // elementInjectors and rootElementInjectors
       var protoElementInjector = binder.protoElementInjector;
       if (isPresent(protoElementInjector)) {
-        var parentElementInjector = isPresent(protoElementInjector.parent) ? elementInjectors[protoElementInjector.parent.index] : null;
-        elementInjector = protoElementInjector.instantiate(parentElementInjector, hostElementInjector);
-        if (isBlank(parentElementInjector)) {
+        if (isPresent(protoElementInjector.parent)) {
+          var parentElementInjector = elementInjectors[protoElementInjector.parent.index];
+          elementInjector = protoElementInjector.instantiate(parentElementInjector, null);
+        } else {
+          elementInjector = protoElementInjector.instantiate(null, hostElementInjector);
           ListWrapper.push(rootElementInjectors, elementInjector);
         }
       }