From 56a8eb3a946c2855aef425575cba5391ea8c1e42 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Tue, 24 Jan 2017 15:05:34 -0800
Subject: [PATCH] Check that sender is a WebContents instance

---
 lib/browser/rpc-server.js |  6 ++++--
 spec/api-ipc-spec.js      | 10 ++++++----
 spec/static/main.js       | 14 ++++++++------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/lib/browser/rpc-server.js b/lib/browser/rpc-server.js
index 1277e51ff439..1dac51645926 100644
--- a/lib/browser/rpc-server.js
+++ b/lib/browser/rpc-server.js
@@ -3,6 +3,8 @@
 const {Buffer} = require('buffer')
 const electron = require('electron')
 const v8Util = process.atomBinding('v8_util')
+const {WebContents} = process.atomBinding('web_contents')
+
 const {ipcMain, isPromise, webContents} = electron
 
 const fs = require('fs')
@@ -150,8 +152,8 @@ const removeRemoteListenersAndLogWarning = (meta, args, callIntoRenderer) => {
   let message = `Attempting to call a function in a renderer window that has been closed or released.` +
     `\nFunction provided here: ${meta.location}`
 
-  if (args.length > 0 && args[0].sender && args[0].sender.eventNames) {
-    const sender = args[0].sender
+  if (args.length > 0 && (args[0].sender instanceof WebContents)) {
+    const {sender} = args[0]
     const remoteEvents = sender.eventNames().filter((eventName) => {
       return sender.listeners(eventName).includes(callIntoRenderer)
     })
diff --git a/spec/api-ipc-spec.js b/spec/api-ipc-spec.js
index 32cc25041c52..b1ca29c6a158 100644
--- a/spec/api-ipc-spec.js
+++ b/spec/api-ipc-spec.js
@@ -506,10 +506,12 @@ describe('ipc module', function () {
             'Function provided here: remote-event-handler.html:11:33',
             'Remote event names: remote-handler, other-remote-handler'
           ].join('\n')
-          const {warningMessage, listenerCountBefore, listenerCountAfter} =
-            ipcRenderer.sendSync('try-emit-web-contents-event', w.webContents.id, 'remote-handler')
-          assert.equal(warningMessage, expectedMessage)
-          assert.equal(listenerCountAfter, listenerCountBefore - 1)
+          const results = ipcRenderer.sendSync('try-emit-web-contents-event', w.webContents.id, 'remote-handler')
+          assert.deepEqual(results, {
+            warningMessage: expectedMessage,
+            listenerCountBefore: 2,
+            listenerCountAfter: 1
+          })
           done()
         })
         w.webContents.reload()
diff --git a/spec/static/main.js b/spec/static/main.js
index 50fe5352eb5f..ab16e19c9e3c 100644
--- a/spec/static/main.js
+++ b/spec/static/main.js
@@ -253,13 +253,16 @@ ipcMain.on('prevent-next-new-window', (event, id) => {
 ipcMain.on('try-emit-web-contents-event', (event, id, eventName) => {
   const consoleWarn = console.warn
   let warningMessage = null
-  console.warn = (message) => {
-    warningMessage = message
-  }
-
   const contents = webContents.fromId(id)
   const listenerCountBefore = contents.listenerCount(eventName)
-  contents.emit(eventName, {sender: contents})
+
+  try {
+    console.warn = (message) => warningMessage = message
+    contents.emit(eventName, {sender: contents})
+  } finally {
+    console.warn = consoleWarn
+  }
+
   const listenerCountAfter = contents.listenerCount(eventName)
 
   event.returnValue = {
@@ -267,5 +270,4 @@ ipcMain.on('try-emit-web-contents-event', (event, id, eventName) => {
     listenerCountBefore,
     listenerCountAfter
   }
-  console.warn = consoleWarn
 })