Bug 1410470 - [devtools] Stop using unreliable 'instanceof Ci.nsIDOMWindow'. r=nchevobbe,smaug

Differential Revision: https://phabricator.services.mozilla.com/D127846

devtools/client/webconsole/test/browser/_browser_console.ini

@@ -52,6 +52,7 @@ skip-if =
   os == "mac" && webrender # Bug 1689000
   os == "linux" && debug # Bug 1689000
 [browser_console_webextension.js]
+[browser_console_window_object_inheritance.js]
 [browser_toolbox_console_new_process.js]
 skip-if =
   asan || debug || ccov # Bug 1591590

devtools/client/webconsole/test/browser/browser_console_window_object_inheritance.js

@@ -0,0 +1,69 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function() {
+  await addTab("about:blank");
+
+  info(`Open browser console`);
+  const hud = await BrowserConsoleManager.openBrowserConsoleOrFocus();
+
+  info(`Clear existing messages`);
+  const onMessagesCleared = hud.ui.once("messages-cleared");
+  await clearOutput(hud);
+  await onMessagesCleared;
+
+  info(`Create a DOM window object`);
+  await hud.commands.scriptCommand.execute(`
+    globalThis.myBrowser = Services.appShell.createWindowlessBrowser();
+    globalThis.myWindow = myBrowser.document.defaultView;
+  `);
+
+  info(`Check objects inheriting from a DOM window`);
+  async function check(input, expected, name) {
+    const msg = await executeAndWaitForMessage(
+      hud,
+      input,
+      "",
+      ".message.result"
+    );
+    is(msg.node.querySelector(".message-body").textContent, expected, name);
+  }
+  await check("Object.create(myWindow)", "Object {  }", "Empty object");
+  await check(
+    "Object.create(myWindow, { location: { value: 1, enumerable: true } })",
+    "Object { location: 1 }",
+    "Object with 'location' property"
+  );
+  await check(
+    `Object.create(myWindow, {
+      location: {
+        get() {
+          console.error("pwned!");
+          return { href: "Oops" };
+        },
+        enumerable: true,
+      },
+    })`,
+    "Object { location: Getter }",
+    "Object with 'location' unsafe getter"
+  );
+
+  info(`Check that no error was logged`);
+  // wait a bit so potential errors can be printed
+  await wait(1000);
+  const error = findMessage(hud, "", ".message.error:not(.network)");
+  if (error) {
+    ok(false, `Got error ${JSON.stringify(error.textContent)}`);
+  } else {
+    ok(true, "No error was logged");
+  }
+
+  info(`Cleanup`);
+  await hud.commands.scriptCommand.execute(`
+    myBrowser.close();
+    delete globalThis.myBrowser;
+    delete globalThis.myWindow;
+  `);
+});

devtools/server/actors/object/previewers.js

@@ -692,21 +692,22 @@ previewers.Object = [
   },
 
   function ObjectWithURL({ obj, hooks }, grip, rawObj) {
+    if (isWorker || !rawObj) {
+      return false;
+    }
+
+    const isWindow = Window.isInstance(rawObj);
     if (
-      isWorker ||
-      !rawObj ||
-      !(
-        obj.class == "CSSImportRule" ||
-        obj.class == "CSSStyleSheet" ||
-        obj.class == "Location" ||
-        rawObj instanceof Ci.nsIDOMWindow
-      )
+      obj.class != "CSSImportRule" &&
+      obj.class != "CSSStyleSheet" &&
+      obj.class != "Location" &&
+      !isWindow
     ) {
       return false;
     }
 
     let url;
-    if (rawObj instanceof Ci.nsIDOMWindow && rawObj.location) {
+    if (isWindow && rawObj.location) {
       url = rawObj.location.href;
     } else if (rawObj.href) {
       url = rawObj.href;

devtools/shared/builtin-modules.js

@@ -63,6 +63,7 @@ const debuggerSandbox = (exports.internalSandbox = Cu.Sandbox(systemPrincipal, {
     "TextDecoder",
     "TextEncoder",
     "URL",
+    "Window",
     "XMLHttpRequest",
   ],
 }));
@@ -87,6 +88,7 @@ const {
   TextDecoder,
   TextEncoder,
   URL,
+  Window,
   XMLHttpRequest,
 } = debuggerSandbox;
 
@@ -280,6 +282,7 @@ exports.globals = {
   TextDecoder,
   TextEncoder,
   URL,
+  Window,
   XMLHttpRequest,
 };
 // DevTools loader copy globals property descriptors on each module global

js/xpconnect/src/Sandbox.cpp

@@ -79,6 +79,7 @@
 #include "mozilla/dom/URLSearchParamsBinding.h"
 #include "mozilla/dom/XMLHttpRequest.h"
 #include "mozilla/dom/WebSocketBinding.h"
+#include "mozilla/dom/WindowBinding.h"
 #include "mozilla/dom/XMLSerializerBinding.h"
 #include "mozilla/dom/FormDataBinding.h"
 #include "mozilla/dom/nsCSPContext.h"
@@ -946,6 +947,8 @@ bool xpc::GlobalProperties::Parse(JSContext* cx, JS::HandleObject obj) {
       XMLHttpRequest = true;
     } else if (JS_LinearStringEqualsLiteral(nameStr, "WebSocket")) {
       WebSocket = true;
+    } else if (JS_LinearStringEqualsLiteral(nameStr, "Window")) {
+      Window = true;
     } else if (JS_LinearStringEqualsLiteral(nameStr, "XMLSerializer")) {
       XMLSerializer = true;
     } else if (JS_LinearStringEqualsLiteral(nameStr, "atob")) {
@@ -1099,6 +1102,8 @@ bool xpc::GlobalProperties::Define(JSContext* cx, JS::HandleObject obj) {
   if (WebSocket && !dom::WebSocket_Binding::GetConstructorObject(cx))
     return false;
 
+  if (Window && !dom::Window_Binding::GetConstructorObject(cx)) return false;
+
   if (XMLSerializer && !dom::XMLSerializer_Binding::GetConstructorObject(cx))
     return false;
 

js/xpconnect/src/xpcprivate.h

@@ -2245,6 +2245,7 @@ struct GlobalProperties {
   bool URLSearchParams : 1;
   bool XMLHttpRequest : 1;
   bool WebSocket : 1;
+  bool Window : 1;
   bool XMLSerializer : 1;
 
   // Ad-hoc property names we implement.