From a00d36fb071be1344396ee90279cb5bbadcf9e0e Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Fri, 21 Apr 2017 12:19:37 -0700
Subject: [PATCH 1/2] Add spec for alert/confirm toString errors

---
 spec/chromium-spec.js | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/spec/chromium-spec.js b/spec/chromium-spec.js
index 6a5937bbce26..4c5b85521ac2 100644
--- a/spec/chromium-spec.js
+++ b/spec/chromium-spec.js
@@ -880,4 +880,28 @@ describe('chromium feature', function () {
       })
     })
   })
+
+  describe('window.alert(message, title)', function () {
+    it('throws an exception when the arguments cannot be converted to strings', function () {
+      assert.throws(function () {
+        window.alert({toString: null})
+      }, /Cannot convert object to primitive value/)
+
+      assert.throws(function () {
+        window.alert('message', {toString: 3})
+      }, /Cannot convert object to primitive value/)
+    })
+  })
+
+  describe('window.confirm(message, title)', function () {
+    it('throws an exception when the arguments cannot be converted to strings', function () {
+      assert.throws(function () {
+        window.confirm({toString: null}, 'title')
+      }, /Cannot convert object to primitive value/)
+
+      assert.throws(function () {
+        window.confirm('message', {toString: 3})
+      }, /Cannot convert object to primitive value/)
+    })
+  })
 })

From c90fd4dc888662599a2f13d60eb39849db926abc Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Fri, 21 Apr 2017 12:21:05 -0700
Subject: [PATCH 2/2] Convert message/title to strings in render process

---
 lib/renderer/window-setup.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/renderer/window-setup.js b/lib/renderer/window-setup.js
index 21f0741a22aa..d29133c88f0b 100644
--- a/lib/renderer/window-setup.js
+++ b/lib/renderer/window-setup.js
@@ -121,11 +121,11 @@ module.exports = (ipcRenderer, guestInstanceId, openerId, hiddenPage) => {
   }
 
   window.alert = function (message, title) {
-    ipcRenderer.sendSync('ELECTRON_BROWSER_WINDOW_ALERT', message, title)
+    ipcRenderer.sendSync('ELECTRON_BROWSER_WINDOW_ALERT', `${message}`, `${title}`)
   }
 
   window.confirm = function (message, title) {
-    return ipcRenderer.sendSync('ELECTRON_BROWSER_WINDOW_CONFIRM', message, title)
+    return ipcRenderer.sendSync('ELECTRON_BROWSER_WINDOW_CONFIRM', `${message}`, `${title}`)
   }
 
   // But we do not support prompt().