From ba8f80267c2874307357cf0bf99457a29b9a9d19 Mon Sep 17 00:00:00 2001
From: Milan Burda <milan.burda@gmail.com>
Date: Wed, 23 Oct 2019 06:44:21 +0200
Subject: [PATCH] fix: send ELECTRON_BROWSER_CONTEXT_RELEASE asynchronously
 (#20632)

* fix: send ELECTRON_BROWSER_CONTEXT_RELEASE asynchronously

* test: remote references should be able to be cleared for all cases
---
 lib/browser/remote/objects-registry.ts   |  4 ++++
 lib/browser/remote/server.ts             |  1 -
 lib/renderer/api/remote.js               |  2 +-
 spec-main/api-remote-spec.ts             | 30 +++++++++++++++++++++---
 spec-main/fixtures/api/send-on-exit.html | 11 +++++++++
 5 files changed, 43 insertions(+), 5 deletions(-)
 create mode 100644 spec-main/fixtures/api/send-on-exit.html

diff --git a/lib/browser/remote/objects-registry.ts b/lib/browser/remote/objects-registry.ts
index 97fa39c5eede..0de48c3960d6 100644
--- a/lib/browser/remote/objects-registry.ts
+++ b/lib/browser/remote/objects-registry.ts
@@ -127,6 +127,10 @@ class ObjectsRegistry {
         this.clear(webContents, contextId)
       }
     }
+    // Note that the "render-view-deleted" event may not be emitted on time when
+    // the renderer process get destroyed because of navigation, we rely on the
+    // renderer process to send "ELECTRON_BROWSER_CONTEXT_RELEASE" message to
+    // guard this situation.
     webContents.on('render-view-deleted' as any, listener)
   }
 }
diff --git a/lib/browser/remote/server.ts b/lib/browser/remote/server.ts
index d1cfab1e8019..5dcf3b884802 100644
--- a/lib/browser/remote/server.ts
+++ b/lib/browser/remote/server.ts
@@ -541,7 +541,6 @@ handleRemoteCommand('ELECTRON_BROWSER_DEREFERENCE', function (event, contextId,
 
 handleRemoteCommand('ELECTRON_BROWSER_CONTEXT_RELEASE', (event, contextId) => {
   objectsRegistry.clear(event.sender, contextId)
-  return null
 })
 
 handleRemoteCommand('ELECTRON_BROWSER_GUEST_WEB_CONTENTS', function (event, contextId, guestInstanceId, stack) {
diff --git a/lib/renderer/api/remote.js b/lib/renderer/api/remote.js
index ebe6e62ecbda..53087896d908 100644
--- a/lib/renderer/api/remote.js
+++ b/lib/renderer/api/remote.js
@@ -19,7 +19,7 @@ const contextId = v8Util.getHiddenValue(global, 'contextId')
 // to guard that situation.
 process.on('exit', () => {
   const command = 'ELECTRON_BROWSER_CONTEXT_RELEASE'
-  ipcRendererInternal.sendSync(command, contextId)
+  ipcRendererInternal.send(command, contextId)
 })
 
 // Convert the arguments object into an array of meta data.
diff --git a/spec-main/api-remote-spec.ts b/spec-main/api-remote-spec.ts
index 130576811c55..13d8e3b9ce0c 100644
--- a/spec-main/api-remote-spec.ts
+++ b/spec-main/api-remote-spec.ts
@@ -1,18 +1,21 @@
+import * as path from 'path'
 import { expect } from 'chai'
 import { closeWindow } from './window-helpers'
 import { ifdescribe } from './spec-helpers';
 
-import { BrowserWindow } from 'electron'
+import { ipcMain, BrowserWindow } from 'electron'
 
 const features = process.electronBinding('features')
 
 ifdescribe(features.isRemoteModuleEnabled())('remote module', () => {
+  const fixtures = path.join(__dirname, 'fixtures')
+
   let w = null as unknown as BrowserWindow
-  before(async () => {
+  beforeEach(async () => {
     w = new BrowserWindow({show: false, webPreferences: {nodeIntegration: true}})
     await w.loadURL('about:blank')
   })
-  after(async () => {
+  afterEach(async () => {
     await closeWindow(w)
   })
 
@@ -112,4 +115,25 @@ ifdescribe(features.isRemoteModuleEnabled())('remote module', () => {
       await expect(remotely(`require('electron').remote.getCurrentWebContents()`)).to.eventually.be.rejected(`Blocked remote.getCurrentWebContents()`)
     })
   })
+
+  describe('remote references', () => {
+    it('render-view-deleted is sent when page is destroyed', (done) => {
+      w.webContents.once('render-view-deleted' as any, () => {
+        done()
+      })
+      w.destroy()
+    })
+
+    // The ELECTRON_BROWSER_CONTEXT_RELEASE message relies on this to work.
+    it('message can be sent on exit when page is being navigated', (done) => {
+      after(() => { ipcMain.removeAllListeners('SENT_ON_EXIT') })
+      ipcMain.once('SENT_ON_EXIT', () => {
+        done()
+      })
+      w.webContents.once('did-finish-load', () => {
+        w.webContents.loadURL('about:blank')
+      })
+      w.loadFile(path.join(fixtures, 'api', 'send-on-exit.html'))
+    })
+  })
 })
diff --git a/spec-main/fixtures/api/send-on-exit.html b/spec-main/fixtures/api/send-on-exit.html
new file mode 100644
index 000000000000..8be9b4b06a77
--- /dev/null
+++ b/spec-main/fixtures/api/send-on-exit.html
@@ -0,0 +1,11 @@
+<html>
+<body>
+<script type="text/javascript" charset="utf-8">
+  const {ipcRenderer} = require('electron')
+
+  process.on('exit', () => {
+    ipcRenderer.send('SENT_ON_EXIT')
+  })
+</script>
+</body>
+</html>