From e747d5e88841c3a0f2c59956399b21fbc084bea7 Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Wed, 7 Aug 2019 18:21:33 -0400
Subject: [PATCH 01/10] fix(ssr): Memory leak in poll method, take 2 (fix
 #2606)

---
 flow/declarations.js    |  1 +
 src/components/view.js  |  7 +++++++
 src/create-route-map.js |  1 +
 src/history/base.js     | 38 ++++++++++++--------------------------
 4 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/flow/declarations.js b/flow/declarations.js
index 942aa73bf..554e214f1 100644
--- a/flow/declarations.js
+++ b/flow/declarations.js
@@ -68,6 +68,7 @@ declare type RouteRecord = {
   regex: RouteRegExp;
   components: Dictionary<any>;
   instances: Dictionary<any>;
+  pendingCbs: Dictionary<Function>;
   name: ?string;
   parent: ?RouteRecord;
   redirect: ?RedirectOption;
diff --git a/src/components/view.js b/src/components/view.js
index 3f440d5b4..b672ccc04 100644
--- a/src/components/view.js
+++ b/src/components/view.js
@@ -1,5 +1,6 @@
 import { warn } from '../util/warn'
 import { extend } from '../util/misc'
+import { tryFinalizeTransition } from '../history/base'
 
 export default {
   name: 'RouterView',
@@ -63,6 +64,10 @@ export default {
         (!val && current === vm)
       ) {
         matched.instances[name] = val
+        // if the route transition has already been confirmed then we weren't
+        // able to call the cb during confirmation as the component was not
+        // registered yet, so we call it here.
+        tryFinalizeTransition(matched, name)
       }
     }
 
@@ -70,6 +75,7 @@ export default {
     // in case the same component instance is reused across different routes
     ;(data.hook || (data.hook = {})).prepatch = (_, vnode) => {
       matched.instances[name] = vnode.componentInstance
+      tryFinalizeTransition(matched, name)
     }
 
     // register instance in init hook
@@ -80,6 +86,7 @@ export default {
         vnode.componentInstance !== matched.instances[name]
       ) {
         matched.instances[name] = vnode.componentInstance
+        tryFinalizeTransition(matched, name)
       }
     }
 
diff --git a/src/create-route-map.js b/src/create-route-map.js
index 0f790108c..6d9608fbb 100644
--- a/src/create-route-map.js
+++ b/src/create-route-map.js
@@ -73,6 +73,7 @@ function addRouteRecord (
     regex: compileRouteRegex(normalizedPath, pathToRegexpOptions),
     components: route.components || { default: route.component },
     instances: {},
+    pendingCbs: {},
     name,
     parent,
     matchAs,
diff --git a/src/history/base.js b/src/history/base.js
index 2b12e1967..2eff355a0 100644
--- a/src/history/base.js
+++ b/src/history/base.js
@@ -178,10 +178,9 @@ export class History {
 
     runQueue(queue, iterator, () => {
       const postEnterCbs = []
-      const isValid = () => this.current === route
       // wait until async components are resolved before
       // extracting in-component enter guards
-      const enterGuards = extractEnterGuards(activated, postEnterCbs, isValid)
+      const enterGuards = extractEnterGuards(activated, postEnterCbs)
       const queue = enterGuards.concat(this.router.resolveHooks)
       runQueue(queue, iterator, () => {
         if (this.pending !== route) {
@@ -299,13 +298,12 @@ function bindGuard (guard: NavigationGuard, instance: ?_Vue): ?NavigationGuard {
 function extractEnterGuards (
   activated: Array<RouteRecord>,
   cbs: Array<Function>,
-  isValid: () => boolean
 ): Array<?Function> {
   return extractGuards(
     activated,
     'beforeRouteEnter',
     (guard, _, match, key) => {
-      return bindEnterGuard(guard, match, key, cbs, isValid)
+      return bindEnterGuard(guard, match, key, cbs)
     }
   )
 }
@@ -315,18 +313,15 @@ function bindEnterGuard (
   match: RouteRecord,
   key: string,
   cbs: Array<Function>,
-  isValid: () => boolean
 ): NavigationGuard {
   return function routeEnterGuard (to, from, next) {
     return guard(to, from, cb => {
       if (typeof cb === 'function') {
+        match.pendingCbs[key] = cb
         cbs.push(() => {
-          // #750
-          // if a router-view is wrapped with an out-in transition,
-          // the instance may not have been registered at this time.
-          // we will need to poll for registration until current route
-          // is no longer valid.
-          poll(cb, match.instances, key, isValid)
+          // if the instance is registered call the cb here, otherwise it will
+          // get called when it is registered in the component's lifecycle hooks
+          tryFinalizeTransition(match, key)
         })
       }
       next(cb)
@@ -334,20 +329,11 @@ function bindEnterGuard (
   }
 }
 
-function poll (
-  cb: any, // somehow flow cannot infer this is a function
-  instances: Object,
-  key: string,
-  isValid: () => boolean
-) {
-  if (
-    instances[key] &&
-    !instances[key]._isBeingDestroyed // do not reuse being destroyed instance
-  ) {
-    cb(instances[key])
-  } else if (isValid()) {
-    setTimeout(() => {
-      poll(cb, instances, key, isValid)
-    }, 16)
+export function tryFinalizeTransition (record: RouteRecord, name: string) {
+  if (record.instances[name] && record.pendingCbs[name]) {
+    const instance = record.instances[name]
+    const cb = record.pendingCbs[name]
+    delete record.pendingCbs[name]
+    cb(instance)
   }
 }

From 062a5aa29c2b1dae5b08d585608f82fb62c5dede Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Wed, 7 Aug 2019 20:52:47 -0400
Subject: [PATCH 02/10] fix: cb called before data init in keep-alive view and
 mixin guards not being called

---
 flow/declarations.js   |  2 +-
 src/components/view.js |  9 ++++-----
 src/history/base.js    | 16 +++++-----------
 src/util/route.js      | 11 +++++++++++
 4 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/flow/declarations.js b/flow/declarations.js
index 554e214f1..68c2543f9 100644
--- a/flow/declarations.js
+++ b/flow/declarations.js
@@ -68,7 +68,7 @@ declare type RouteRecord = {
   regex: RouteRegExp;
   components: Dictionary<any>;
   instances: Dictionary<any>;
-  pendingCbs: Dictionary<Function>;
+  pendingCbs: Dictionary<Array<Function>>;
   name: ?string;
   parent: ?RouteRecord;
   redirect: ?RedirectOption;
diff --git a/src/components/view.js b/src/components/view.js
index b672ccc04..9e2d54333 100644
--- a/src/components/view.js
+++ b/src/components/view.js
@@ -1,6 +1,6 @@
 import { warn } from '../util/warn'
 import { extend } from '../util/misc'
-import { tryFinalizeTransition } from '../history/base'
+import { tryFinalizeTransition } from '../util/route'
 
 export default {
   name: 'RouterView',
@@ -64,10 +64,6 @@ export default {
         (!val && current === vm)
       ) {
         matched.instances[name] = val
-        // if the route transition has already been confirmed then we weren't
-        // able to call the cb during confirmation as the component was not
-        // registered yet, so we call it here.
-        tryFinalizeTransition(matched, name)
       }
     }
 
@@ -75,6 +71,9 @@ export default {
     // in case the same component instance is reused across different routes
     ;(data.hook || (data.hook = {})).prepatch = (_, vnode) => {
       matched.instances[name] = vnode.componentInstance
+      // if the route transition has already been confirmed then we weren't
+      // able to call the cb during confirmation as the component was not
+      // registered yet, so we call it here.
       tryFinalizeTransition(matched, name)
     }
 
diff --git a/src/history/base.js b/src/history/base.js
index 2eff355a0..5ac52e692 100644
--- a/src/history/base.js
+++ b/src/history/base.js
@@ -5,7 +5,7 @@ import type Router from '../index'
 import { inBrowser } from '../util/dom'
 import { runQueue } from '../util/async'
 import { warn, isError, isExtendedError } from '../util/warn'
-import { START, isSameRoute } from '../util/route'
+import { START, isSameRoute, tryFinalizeTransition } from '../util/route'
 import {
   flatten,
   flatMapComponents,
@@ -317,7 +317,10 @@ function bindEnterGuard (
   return function routeEnterGuard (to, from, next) {
     return guard(to, from, cb => {
       if (typeof cb === 'function') {
-        match.pendingCbs[key] = cb
+        if (!match.pendingCbs[key]) {
+          match.pendingCbs[key] = []
+        }
+        match.pendingCbs[key].push(cb)
         cbs.push(() => {
           // if the instance is registered call the cb here, otherwise it will
           // get called when it is registered in the component's lifecycle hooks
@@ -328,12 +331,3 @@ function bindEnterGuard (
     })
   }
 }
-
-export function tryFinalizeTransition (record: RouteRecord, name: string) {
-  if (record.instances[name] && record.pendingCbs[name]) {
-    const instance = record.instances[name]
-    const cb = record.pendingCbs[name]
-    delete record.pendingCbs[name]
-    cb(instance)
-  }
-}
diff --git a/src/util/route.js b/src/util/route.js
index 54a91a738..79d8fcee5 100644
--- a/src/util/route.js
+++ b/src/util/route.js
@@ -130,3 +130,14 @@ function queryIncludes (current: Dictionary<string>, target: Dictionary<string>)
   }
   return true
 }
+
+export function tryFinalizeTransition (record: RouteRecord, name: string) {
+  if (record.instances[name] && record.pendingCbs[name]) {
+    const instance = record.instances[name]
+    const cbs = record.pendingCbs[name]
+    delete record.pendingCbs[name]
+    for (let i = 0; i < cbs.length; i++) {
+      cbs[i](instance)
+    }
+  }
+}

From 71d0088bbbc42454e94467ba0ccfb09e76c4e271 Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Thu, 8 Aug 2019 00:46:07 -0400
Subject: [PATCH 03/10] refactor: renamed things for clarity

---
 flow/declarations.js   |  2 +-
 src/components/view.js |  7 ++++---
 src/history/base.js    | 16 ++++++++--------
 src/util/route.js      |  8 ++++----
 4 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/flow/declarations.js b/flow/declarations.js
index 68c2543f9..ee1a10283 100644
--- a/flow/declarations.js
+++ b/flow/declarations.js
@@ -68,7 +68,7 @@ declare type RouteRecord = {
   regex: RouteRegExp;
   components: Dictionary<any>;
   instances: Dictionary<any>;
-  pendingCbs: Dictionary<Array<Function>>;
+  enteredCbs: Dictionary<Array<Function>>;
   name: ?string;
   parent: ?RouteRecord;
   redirect: ?RedirectOption;
diff --git a/src/components/view.js b/src/components/view.js
index 9e2d54333..e64be5156 100644
--- a/src/components/view.js
+++ b/src/components/view.js
@@ -1,6 +1,6 @@
 import { warn } from '../util/warn'
 import { extend } from '../util/misc'
-import { tryFinalizeTransition } from '../util/route'
+import { handleRouteEntered } from '../util/route'
 
 export default {
   name: 'RouterView',
@@ -74,7 +74,8 @@ export default {
       // if the route transition has already been confirmed then we weren't
       // able to call the cb during confirmation as the component was not
       // registered yet, so we call it here.
-      tryFinalizeTransition(matched, name)
+      matched.enteredCbs
+      handleRouteEntered(matched, name)
     }
 
     // register instance in init hook
@@ -85,7 +86,7 @@ export default {
         vnode.componentInstance !== matched.instances[name]
       ) {
         matched.instances[name] = vnode.componentInstance
-        tryFinalizeTransition(matched, name)
+        handleRouteEntered(matched, name)
       }
     }
 
diff --git a/src/history/base.js b/src/history/base.js
index 5ac52e692..9072ceeba 100644
--- a/src/history/base.js
+++ b/src/history/base.js
@@ -5,7 +5,7 @@ import type Router from '../index'
 import { inBrowser } from '../util/dom'
 import { runQueue } from '../util/async'
 import { warn, isError, isExtendedError } from '../util/warn'
-import { START, isSameRoute, tryFinalizeTransition } from '../util/route'
+import { START, isSameRoute, handleRouteEntered } from '../util/route'
 import {
   flatten,
   flatMapComponents,
@@ -177,10 +177,10 @@ export class History {
     }
 
     runQueue(queue, iterator, () => {
-      const postEnterCbs = []
+      const enteredCbs = []
       // wait until async components are resolved before
       // extracting in-component enter guards
-      const enterGuards = extractEnterGuards(activated, postEnterCbs)
+      const enterGuards = extractEnterGuards(activated, enteredCbs)
       const queue = enterGuards.concat(this.router.resolveHooks)
       runQueue(queue, iterator, () => {
         if (this.pending !== route) {
@@ -190,7 +190,7 @@ export class History {
         onComplete(route)
         if (this.router.app) {
           this.router.app.$nextTick(() => {
-            postEnterCbs.forEach(cb => {
+            enteredCbs.forEach(cb => {
               cb()
             })
           })
@@ -317,14 +317,14 @@ function bindEnterGuard (
   return function routeEnterGuard (to, from, next) {
     return guard(to, from, cb => {
       if (typeof cb === 'function') {
-        if (!match.pendingCbs[key]) {
-          match.pendingCbs[key] = []
+        if (!match.enteredCbs[key]) {
+          match.enteredCbs[key] = []
         }
-        match.pendingCbs[key].push(cb)
+        match.enteredCbs[key].push(cb)
         cbs.push(() => {
           // if the instance is registered call the cb here, otherwise it will
           // get called when it is registered in the component's lifecycle hooks
-          tryFinalizeTransition(match, key)
+          handleRouteEntered(match, key)
         })
       }
       next(cb)
diff --git a/src/util/route.js b/src/util/route.js
index 79d8fcee5..84bb10c45 100644
--- a/src/util/route.js
+++ b/src/util/route.js
@@ -131,11 +131,11 @@ function queryIncludes (current: Dictionary<string>, target: Dictionary<string>)
   return true
 }
 
-export function tryFinalizeTransition (record: RouteRecord, name: string) {
-  if (record.instances[name] && record.pendingCbs[name]) {
+export function handleRouteEntered (record: RouteRecord, name: string) {
+  if (record.instances[name] && record.enteredCbs[name]) {
     const instance = record.instances[name]
-    const cbs = record.pendingCbs[name]
-    delete record.pendingCbs[name]
+    const cbs = record.enteredCbs[name]
+    delete record.enteredCbs[name]
     for (let i = 0; i < cbs.length; i++) {
       cbs[i](instance)
     }

From 429a38c6af785cfe5bbf1665bf7d77253842ea9c Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Thu, 8 Aug 2019 00:47:42 -0400
Subject: [PATCH 04/10] fix: fixed bug from refactoring

---
 src/create-route-map.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/create-route-map.js b/src/create-route-map.js
index 6d9608fbb..232e25e66 100644
--- a/src/create-route-map.js
+++ b/src/create-route-map.js
@@ -73,7 +73,7 @@ function addRouteRecord (
     regex: compileRouteRegex(normalizedPath, pathToRegexpOptions),
     components: route.components || { default: route.component },
     instances: {},
-    pendingCbs: {},
+    enteredCbs: {},
     name,
     parent,
     matchAs,

From aff081e712f98b605ea85aedc0e49968c35870e1 Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Thu, 8 Aug 2019 01:23:36 -0400
Subject: [PATCH 05/10] refactor: a little bit more refactoring

---
 src/components/view.js | 12 ++++++------
 src/history/base.js    |  4 +++-
 src/util/route.js      | 13 ++++++-------
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/src/components/view.js b/src/components/view.js
index e64be5156..d5c71d5c9 100644
--- a/src/components/view.js
+++ b/src/components/view.js
@@ -71,11 +71,6 @@ export default {
     // in case the same component instance is reused across different routes
     ;(data.hook || (data.hook = {})).prepatch = (_, vnode) => {
       matched.instances[name] = vnode.componentInstance
-      // if the route transition has already been confirmed then we weren't
-      // able to call the cb during confirmation as the component was not
-      // registered yet, so we call it here.
-      matched.enteredCbs
-      handleRouteEntered(matched, name)
     }
 
     // register instance in init hook
@@ -86,7 +81,12 @@ export default {
         vnode.componentInstance !== matched.instances[name]
       ) {
         matched.instances[name] = vnode.componentInstance
-        handleRouteEntered(matched, name)
+        // if the route transition has already been confirmed then we weren't
+        // able to call the cbs during confirmation as the component was not
+        // registered yet, so we call it here.
+        if (matched.enteredCbs[name]) {
+          handleRouteEntered(matched, name)
+        }
       }
     }
 
diff --git a/src/history/base.js b/src/history/base.js
index 9072ceeba..c0bd8fcc4 100644
--- a/src/history/base.js
+++ b/src/history/base.js
@@ -324,7 +324,9 @@ function bindEnterGuard (
         cbs.push(() => {
           // if the instance is registered call the cb here, otherwise it will
           // get called when it is registered in the component's lifecycle hooks
-          handleRouteEntered(match, key)
+          if (match.instances[key]) {
+            handleRouteEntered(match, key)
+          }
         })
       }
       next(cb)
diff --git a/src/util/route.js b/src/util/route.js
index 84bb10c45..5d4c7ad18 100644
--- a/src/util/route.js
+++ b/src/util/route.js
@@ -132,12 +132,11 @@ function queryIncludes (current: Dictionary<string>, target: Dictionary<string>)
 }
 
 export function handleRouteEntered (record: RouteRecord, name: string) {
-  if (record.instances[name] && record.enteredCbs[name]) {
-    const instance = record.instances[name]
-    const cbs = record.enteredCbs[name]
-    delete record.enteredCbs[name]
-    for (let i = 0; i < cbs.length; i++) {
-      cbs[i](instance)
-    }
+  const instance = record.instances[name]
+  const cbs = record.enteredCbs[name]
+  if (!instance || !cbs) return
+  delete record.enteredCbs[name]
+  for (let i = 0; i < cbs.length; i++) {
+    cbs[i](instance)
   }
 }

From ecd71e7df5ffaeef9a134e710e75c34b0936876c Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Fri, 9 Aug 2019 00:02:46 -0400
Subject: [PATCH 06/10] fix: fixed enter cb not called in out-in transitions
 still

---
 src/components/view.js | 11 +++++------
 src/history/base.js    | 22 +++++-----------------
 src/util/route.js      | 19 ++++++++++++-------
 3 files changed, 22 insertions(+), 30 deletions(-)

diff --git a/src/components/view.js b/src/components/view.js
index d5c71d5c9..53b0495f6 100644
--- a/src/components/view.js
+++ b/src/components/view.js
@@ -81,13 +81,12 @@ export default {
         vnode.componentInstance !== matched.instances[name]
       ) {
         matched.instances[name] = vnode.componentInstance
-        // if the route transition has already been confirmed then we weren't
-        // able to call the cbs during confirmation as the component was not
-        // registered yet, so we call it here.
-        if (matched.enteredCbs[name]) {
-          handleRouteEntered(matched, name)
-        }
       }
+
+      // if the route transition has already been confirmed then we weren't
+      // able to call the cbs during confirmation as the component was not
+      // registered yet, so we call it here.
+      handleRouteEntered(route)
     }
 
     // resolve props
diff --git a/src/history/base.js b/src/history/base.js
index c0bd8fcc4..b8a8eeb29 100644
--- a/src/history/base.js
+++ b/src/history/base.js
@@ -177,10 +177,9 @@ export class History {
     }
 
     runQueue(queue, iterator, () => {
-      const enteredCbs = []
       // wait until async components are resolved before
       // extracting in-component enter guards
-      const enterGuards = extractEnterGuards(activated, enteredCbs)
+      const enterGuards = extractEnterGuards(activated)
       const queue = enterGuards.concat(this.router.resolveHooks)
       runQueue(queue, iterator, () => {
         if (this.pending !== route) {
@@ -190,9 +189,7 @@ export class History {
         onComplete(route)
         if (this.router.app) {
           this.router.app.$nextTick(() => {
-            enteredCbs.forEach(cb => {
-              cb()
-            })
+            handleRouteEntered(route)
           })
         }
       })
@@ -296,14 +293,13 @@ function bindGuard (guard: NavigationGuard, instance: ?_Vue): ?NavigationGuard {
 }
 
 function extractEnterGuards (
-  activated: Array<RouteRecord>,
-  cbs: Array<Function>,
+  activated: Array<RouteRecord>
 ): Array<?Function> {
   return extractGuards(
     activated,
     'beforeRouteEnter',
     (guard, _, match, key) => {
-      return bindEnterGuard(guard, match, key, cbs)
+      return bindEnterGuard(guard, match, key)
     }
   )
 }
@@ -311,8 +307,7 @@ function extractEnterGuards (
 function bindEnterGuard (
   guard: NavigationGuard,
   match: RouteRecord,
-  key: string,
-  cbs: Array<Function>,
+  key: string
 ): NavigationGuard {
   return function routeEnterGuard (to, from, next) {
     return guard(to, from, cb => {
@@ -321,13 +316,6 @@ function bindEnterGuard (
           match.enteredCbs[key] = []
         }
         match.enteredCbs[key].push(cb)
-        cbs.push(() => {
-          // if the instance is registered call the cb here, otherwise it will
-          // get called when it is registered in the component's lifecycle hooks
-          if (match.instances[key]) {
-            handleRouteEntered(match, key)
-          }
-        })
       }
       next(cb)
     })
diff --git a/src/util/route.js b/src/util/route.js
index 5d4c7ad18..609721ee0 100644
--- a/src/util/route.js
+++ b/src/util/route.js
@@ -131,12 +131,17 @@ function queryIncludes (current: Dictionary<string>, target: Dictionary<string>)
   return true
 }
 
-export function handleRouteEntered (record: RouteRecord, name: string) {
-  const instance = record.instances[name]
-  const cbs = record.enteredCbs[name]
-  if (!instance || !cbs) return
-  delete record.enteredCbs[name]
-  for (let i = 0; i < cbs.length; i++) {
-    cbs[i](instance)
+export function handleRouteEntered (route: Route) {
+  for (let i = 0; i < route.matched.length; i++) {
+    const record = route.matched[i]
+    for (const name in record.instances) {
+      const instance = record.instances[name]
+      const cbs = record.enteredCbs[name]
+      if (!instance || !cbs) continue
+      delete record.enteredCbs[name]
+      for (let i = 0; i < cbs.length; i++) {
+        cbs[i](instance)
+      }
+    }
   }
 }

From f340981a4c943639dc30be0cd10e530801b8eebf Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Sat, 10 Aug 2019 14:02:52 -0400
Subject: [PATCH 07/10] chore(test): added coverage for out-in transition
 before route enter cb

---
 examples/navigation-guards/app.js     | 47 +++++++++++++++++++--------
 examples/navigation-guards/index.html |  8 +++++
 2 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/examples/navigation-guards/app.js b/examples/navigation-guards/app.js
index 86b2c9496..85c4af416 100644
--- a/examples/navigation-guards/app.js
+++ b/examples/navigation-guards/app.js
@@ -91,15 +91,25 @@ const Quux = {
 }
 
 const NestedParent = {
-  template: `<div id="nested-parent">Nested Parent <hr>
-  <router-link to="/parent/child/1">/parent/child/1</router-link>
-  <router-link to="/parent/child/2">/parent/child/2</router-link>
-  <hr>
-  <p id="bre-order">
-    <span v-for="log in logs">{{ log }} </span>
-  </p>
-
-  <router-view/></div>`,
+  template: `
+  <div id="nested-parent">
+    Nested Parent
+    <hr>
+    <router-link to="/parent/child/1">/parent/child/1</router-link>
+    <router-link to="/parent/child/2">/parent/child/2</router-link>
+    <hr>
+    <p id="bre-order">
+      <span v-for="log in logs">{{ log }} </span>
+    </p>
+    <!-- #705 -->
+    <!-- Some transitions, specifically out-in transitions, cause the view -->
+    <!-- that is transitioning in to appear significantly later than normal, -->
+    <!-- which can cause bugs as "vm" below in "next(vm => ...)" may not be -->
+    <!-- available at the time the callback is called -->
+    <transition name="fade" mode="out-in">
+      <router-view/>
+    </transition>
+  </div>`,
   data: () => ({ logs: [] }),
   beforeRouteEnter (to, from, next) {
     next(vm => {
@@ -116,7 +126,18 @@ const GuardMixin = {
   }
 }
 
-const NestedChild = {
+const NestedChild1 = {
+  props: ['n'],
+  template: `<div>Child {{ n }}</div>`,
+  mixins: [GuardMixin],
+  beforeRouteEnter (to, from, next) {
+    next(vm => {
+      vm.$parent.logs.push('child ' + vm.n)
+    })
+  }
+}
+
+const NestedChild2 = {
   props: ['n'],
   template: `<div>Child {{ n }}</div>`,
   mixins: [GuardMixin],
@@ -162,10 +183,10 @@ const router = new VueRouter({
       path: '/parent',
       component: NestedParent,
       children: [
-        { path: 'child/1', component: NestedChild, props: { n: 1 }},
-        { path: 'child/2', component: NestedChild, props: { n: 2 }}
+        { path: 'child/1', component: NestedChild1, props: { n: 1 }},
+        { path: 'child/2', component: NestedChild2, props: { n: 2 }}
       ]
-    }
+    },
   ]
 })
 
diff --git a/examples/navigation-guards/index.html b/examples/navigation-guards/index.html
index 0e7e950ee..580cb9768 100644
--- a/examples/navigation-guards/index.html
+++ b/examples/navigation-guards/index.html
@@ -1,5 +1,13 @@
 <!DOCTYPE html>
 <link rel="stylesheet" href="/global.css">
+<style>
+.fade-enter-active, .fade-leave-active {
+  transition: opacity .5s ease;
+}
+.fade-enter, .fade-leave-active {
+  opacity: 0;
+}
+</style>
 <a href="/">&larr; Examples index</a>
 <div id="app"></div>
 <script src="/__build__/shared.chunk.js"></script>

From 493ec4759a84831be1ce35e0856155e4f5df1249 Mon Sep 17 00:00:00 2001
From: Ronald Rogers <ronald.d.rogers@gmail.com>
Date: Sat, 10 Aug 2019 14:20:53 -0400
Subject: [PATCH 08/10] fix: lint

---
 examples/navigation-guards/app.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/navigation-guards/app.js b/examples/navigation-guards/app.js
index 85c4af416..62e526503 100644
--- a/examples/navigation-guards/app.js
+++ b/examples/navigation-guards/app.js
@@ -186,7 +186,7 @@ const router = new VueRouter({
         { path: 'child/1', component: NestedChild1, props: { n: 1 }},
         { path: 'child/2', component: NestedChild2, props: { n: 2 }}
       ]
-    },
+    }
   ]
 })
 

From 84b74ec594c7c31a8becbf52a71a424a4a6190ad Mon Sep 17 00:00:00 2001
From: Eduardo San Martin Morote <posva13@gmail.com>
Date: Mon, 23 Sep 2019 12:10:58 +0200
Subject: [PATCH 09/10] refactor: use one single component

---
 examples/navigation-guards/app.js | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/examples/navigation-guards/app.js b/examples/navigation-guards/app.js
index 62e526503..48de8aa0d 100644
--- a/examples/navigation-guards/app.js
+++ b/examples/navigation-guards/app.js
@@ -107,7 +107,7 @@ const NestedParent = {
     <!-- which can cause bugs as "vm" below in "next(vm => ...)" may not be -->
     <!-- available at the time the callback is called -->
     <transition name="fade" mode="out-in">
-      <router-view/>
+      <router-view :key="$route.path"/>
     </transition>
   </div>`,
   data: () => ({ logs: [] }),
@@ -126,18 +126,7 @@ const GuardMixin = {
   }
 }
 
-const NestedChild1 = {
-  props: ['n'],
-  template: `<div>Child {{ n }}</div>`,
-  mixins: [GuardMixin],
-  beforeRouteEnter (to, from, next) {
-    next(vm => {
-      vm.$parent.logs.push('child ' + vm.n)
-    })
-  }
-}
-
-const NestedChild2 = {
+const NestedChild = {
   props: ['n'],
   template: `<div>Child {{ n }}</div>`,
   mixins: [GuardMixin],
@@ -183,8 +172,8 @@ const router = new VueRouter({
       path: '/parent',
       component: NestedParent,
       children: [
-        { path: 'child/1', component: NestedChild1, props: { n: 1 }},
-        { path: 'child/2', component: NestedChild2, props: { n: 2 }}
+        { path: 'child/1', component: NestedChild, props: { n: 1 }},
+        { path: 'child/2', component: NestedChild, props: { n: 2 }}
       ]
     }
   ]

From 0c8f65aa8fb5cff443bf700642898690fc11eac6 Mon Sep 17 00:00:00 2001
From: Eduardo San Martin Morote <posva13@gmail.com>
Date: Tue, 24 Sep 2019 10:00:30 +0200
Subject: [PATCH 10/10] refactor: add back the isBeingDestroyed check

---
 src/util/route.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/route.js b/src/util/route.js
index 609721ee0..2a15419e0 100644
--- a/src/util/route.js
+++ b/src/util/route.js
@@ -140,7 +140,7 @@ export function handleRouteEntered (route: Route) {
       if (!instance || !cbs) continue
       delete record.enteredCbs[name]
       for (let i = 0; i < cbs.length; i++) {
-        cbs[i](instance)
+        if (!instance._isBeingDestroyed) cbs[i](instance)
       }
     }
   }