From cb67ffe4429ebfbdf42b5d18e1e1b168109d472e Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Sun, 5 Jun 2016 16:14:51 -0400
Subject: [PATCH] ensure abstract HOCs do not alter parent chain

---
 flow/component.js                               |  1 +
 src/core/components/keep-alive.js               |  2 ++
 src/core/instance/lifecycle.js                  |  4 ++--
 src/core/instance/render.js                     | 17 +++++++++++++++--
 src/core/util/env.js                            |  2 +-
 src/core/vdom/create-element.js                 |  2 +-
 .../runtime/components/transition-control.js    |  2 ++
 7 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/flow/component.js b/flow/component.js
index 7debfac1..7ee8d293 100644
--- a/flow/component.js
+++ b/flow/component.js
@@ -47,6 +47,7 @@ declare interface Component {
   _isVue: true;
   _self: Component;
   _renderProxy: Component;
+  _renderParent: ?Component;
   _watcher: Watcher;
   _watchers: Array<Watcher>;
   _data: Object;
diff --git a/src/core/components/keep-alive.js b/src/core/components/keep-alive.js
index 33d9895a..aba7d6c0 100644
--- a/src/core/components/keep-alive.js
+++ b/src/core/components/keep-alive.js
@@ -1,4 +1,6 @@
 export default {
+  name: 'keep-alive',
+  _abstract: true,
   created () {
     this.cache = Object.create(null)
   },
diff --git a/src/core/instance/lifecycle.js b/src/core/instance/lifecycle.js
index 691caa5a..72178a5e 100644
--- a/src/core/instance/lifecycle.js
+++ b/src/core/instance/lifecycle.js
@@ -10,7 +10,7 @@ export function initLifecycle (vm: Component) {
 
   vm.$parent = options.parent
   vm.$root = vm.$parent ? vm.$parent.$root : vm
-  if (vm.$parent) {
+  if (vm.$parent && !options._abstract) {
     vm.$parent.$children.push(vm)
   }
 
@@ -145,7 +145,7 @@ export function lifecycleMixin (Vue: Class<Component>) {
     vm._isBeingDestroyed = true
     // remove self from parent
     const parent = vm.$parent
-    if (parent && !parent._isBeingDestroyed) {
+    if (parent && !parent._isBeingDestroyed && !vm.$options._abstract) {
       remove(parent.$children, vm)
     }
     // teardown watchers
diff --git a/src/core/instance/render.js b/src/core/instance/render.js
index 1e3f320b..7f22eb8b 100644
--- a/src/core/instance/render.js
+++ b/src/core/instance/render.js
@@ -16,7 +16,7 @@ import {
 } from '../vdom/create-element'
 
 export const renderState: {
-  activeInstance: Component | null
+  activeInstance: ?Component
 } = {
   activeInstance: null
 }
@@ -35,6 +35,19 @@ export function initRender (vm: Component) {
   ) {
     return this._h(this._e(tag, data, namespace), children)
   }, vm)
+  // for abstract components, determine first non-abstract parent
+  // so that the children of abstract components are considered children
+  // of the first non-abstract parent.
+  // this is used by internal abstract components like <keep-alive>.
+  if (vm.$options._abstract) {
+    let parent = vm.$parent
+    while (parent && parent.$options._abstract) {
+      parent = parent.$parent
+    }
+    vm._renderParent = parent
+  } else {
+    vm._renderParent = vm
+  }
   if (vm.$options.el) {
     vm.$mount(vm.$options.el)
   }
@@ -48,7 +61,7 @@ export function renderMixin (Vue: Class<Component>) {
   Vue.prototype._render = function (): VNode {
     const vm: Component = this
     const prev = renderState.activeInstance
-    renderState.activeInstance = vm
+    renderState.activeInstance = vm._renderParent
     if (!vm._isMounted) {
       // render static sub-trees for once on initial render
       renderStaticTrees(vm)
diff --git a/src/core/util/env.js b/src/cor