From 324021a31b2532adf13c75b2a5a9c03f524bc78b Mon Sep 17 00:00:00 2001
From: Jeremy Rose <jeremya@chromium.org>
Date: Mon, 23 Nov 2020 09:21:00 -0800
Subject: [PATCH] fix: segfault on webContents.fromId(xxx) (#26609)

---
 docs/api/web-contents.md                       | 3 ++-
 shell/browser/api/electron_api_web_contents.cc | 8 +++++++-
 spec-main/api-web-contents-spec.ts             | 6 ++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/docs/api/web-contents.md b/docs/api/web-contents.md
index 072374cf5b29e..e835925a9f6fa 100644
--- a/docs/api/web-contents.md
+++ b/docs/api/web-contents.md
@@ -42,7 +42,8 @@ returns `null`.
 
 * `id` Integer
 
-Returns `WebContents` - A WebContents instance with the given ID.
+Returns `WebContents` | undefined - A WebContents instance with the given ID, or
+`undefined` if there is no WebContents associated with the given ID.
 
 ## Class: WebContents
 
diff --git a/shell/browser/api/electron_api_web_contents.cc b/shell/browser/api/electron_api_web_contents.cc
index 1de35090d9a75..d24865b724469 100644
--- a/shell/browser/api/electron_api_web_contents.cc
+++ b/shell/browser/api/electron_api_web_contents.cc
@@ -3118,6 +3118,12 @@ namespace {
 using electron::api::GetAllWebContents;
 using electron::api::WebContents;
 
+gin::Handle<WebContents> WebContentsFromID(v8::Isolate* isolate, int32_t id) {
+  WebContents* contents = WebContents::FromID(id);
+  return contents ? gin::CreateHandle(isolate, contents)
+                  : gin::Handle<WebContents>();
+}
+
 std::vector<gin::Handle<WebContents>> GetAllWebContentsAsV8(
     v8::Isolate* isolate) {
   std::vector<gin::Handle<WebContents>> list;
@@ -3136,7 +3142,7 @@ void Initialize(v8::Local<v8::Object> exports,
   gin_helper::Dictionary dict(isolate, exports);
   dict.Set("WebContents", WebContents::GetConstructor(context));
   dict.SetMethod("create", &WebContents::Create);
-  dict.SetMethod("fromId", &WebContents::FromID);
+  dict.SetMethod("fromId", &WebContentsFromID);
   dict.SetMethod("getAllWebContents", &GetAllWebContentsAsV8);
 }
 
diff --git a/spec-main/api-web-contents-spec.ts b/spec-main/api-web-contents-spec.ts
index 1586afbe4e4c7..e38a2688ca78f 100644
--- a/spec-main/api-web-contents-spec.ts
+++ b/spec-main/api-web-contents-spec.ts
@@ -42,6 +42,12 @@ describe('webContents module', () => {
     });
   });
 
+  describe('fromId()', () => {
+    it('returns undefined for an unknown id', () => {
+      expect(webContents.fromId(12345)).to.be.undefined();
+    });
+  });
+
   describe('will-prevent-unload event', function () {
     afterEach(closeAllWindows);
     it('does not emit if beforeunload returns undefined', async () => {