From 32f5d5601aea1c6e89b1c296bf13e9ff254b0105 Mon Sep 17 00:00:00 2001
From: JuniorTour <juniortour@qq.com>
Date: Sat, 16 Jul 2022 01:16:31 +0800
Subject: [PATCH 1/2] fix: post watcher not triggered (fix #12664)

---
 .gitignore                             |  1 +
 src/core/observer/scheduler.ts         |  6 +++-
 test/unit/features/v3/apiWatch.spec.ts | 45 ++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 18c343efc53..4c6ae5bbc66 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,7 @@ packages/server-renderer/client-plugin.js
 packages/template-compiler/build.js
 packages/template-compiler/browser.js
 .vscode
+.idea
 dist
 temp
 types/v3-generated.d.ts
diff --git a/src/core/observer/scheduler.ts b/src/core/observer/scheduler.ts
index 24e711c36fd..0f807f46f3a 100644
--- a/src/core/observer/scheduler.ts
+++ b/src/core/observer/scheduler.ts
@@ -156,7 +156,11 @@ function callActivatedHooks(queue) {
  */
 export function queueWatcher(watcher: Watcher) {
   const id = watcher.id
-  if (has[id] != null) {
+  if (
+    has[id] != null &&
+    // not skip post watcher which id is Infinity
+    id !== Infinity
+  ) {
     return
   }
 
diff --git a/test/unit/features/v3/apiWatch.spec.ts b/test/unit/features/v3/apiWatch.spec.ts
index c1b301ae9e8..eb07e77dac5 100644
--- a/test/unit/features/v3/apiWatch.spec.ts
+++ b/test/unit/features/v3/apiWatch.spec.ts
@@ -672,6 +672,51 @@ describe('api: watch', () => {
     await nextTick()
     expect(dom!.tagName).toBe('P')
   })
+  
+  // #12664
+  it('flush: post watchers from 2 components should both fire after template refs updated', async () => {
+    let appPostWatcherTrigger = false
+    let childComponentPostWatcherTrigger = false
+
+    const Child = {
+      setup() {
+        const el = ref();
+        watch(
+          el,
+          () => {
+            childComponentPostWatcherTrigger = true
+          },
+          {flush: 'post'}
+        )
+        return { el };
+      },
+      template: `<div><span ref="el">hello child</span></div>`
+    }
+    const App = {
+      components: { Child },
+      setup() {
+        const el = ref();
+        watch(
+          el,
+          () => {
+            appPostWatcherTrigger = true
+          },
+          {flush: 'post'}
+        )
+        return { el };
+      },
+      template: `<div><Child /><span ref="el">hello app1</span></div>`
+    }
+
+    const container = document.createElement('div')
+    const root = document.createElement('div')
+    container.appendChild(root)
+    new Vue(App).$mount(root)
+
+    await nextTick()
+    expect(appPostWatcherTrigger).toBe(true)
+    expect(childComponentPostWatcherTrigger).toBe(true)
+  })
 
   it('deep', async () => {
     const state = reactive({

From e7cfe3c2619b5fb6dfa875b7c17236f377888c71 Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Sat, 16 Jul 2022 08:27:16 -0400
Subject: [PATCH 2/2] Update .gitignore

---
 .gitignore | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 4c6ae5bbc66..18c343efc53 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,7 +12,6 @@ packages/server-renderer/client-plugin.js
 packages/template-compiler/build.js
 packages/template-compiler/browser.js
 .vscode
-.idea
 dist
 temp
 types/v3-generated.d.ts