electron · zcbenz · Jun 21, 2021 · Jun 3, 2021 · Jun 3, 2021 · Jun 3, 2021
diff --git a/shell/common/node_bindings.cc b/shell/common/node_bindings.cc
@@ -489,9 +489,13 @@ node::Environment* NodeBindings::CreateEnvironment(
     // Node.js requires that microtask checkpoints be explicitly invoked.
     is.policy = v8::MicrotasksPolicy::kExplicit;
   } else {
-    // Match Blink's behavior by allowing microtasks invocation to be controlled
-    // by MicrotasksScope objects.
-    is.policy = v8::MicrotasksPolicy::kScoped;
+    // Blink expects the microtasks policy to be kScoped, but Node.js expects it
+    // to be kExplicit. In the renderer, there can be many contexts within the
+    // same isolate, so we don't want to change the existing policy here, which
+    // could be either kExplicit or kScoped depending on whether we're executing
+    // from within a Node.js or a Blink entrypoint. Instead, the policy is
+    // toggled to kExplicit when entering Node.js through UvRunOnce.
+    is.policy = context->GetIsolate()->GetMicrotasksPolicy();
 
     // We do not want to use Node.js' message listener as it interferes with
     // Blink's.

diff --git a/spec-main/fixtures/crash-cases/setimmediate-window-open-crash/index.html b/spec-main/fixtures/crash-cases/setimmediate-window-open-crash/index.html
@@ -0,0 +1,21 @@
+<html>
+<body>
+<script>
+// `setImmediate` schedules a function to be run on the next UV tick, which
+//  ensures that `window.open` is run from `UvRunOnce()`.
+setImmediate(async () => {
+  if (!location.hash) {
+    const p = new Promise(resolve => {
+      window.addEventListener('message', resolve, { once: true });
+    });
+    window.open('#foo', '', 'nodeIntegration=no,show=no');
+    const e = await p;
+
+    window.close();
+  } else {
+    window.opener.postMessage('foo', '*');
+  }
+});
+</script>
+</body>
+</html>
diff --git a/spec-main/fixtures/crash-cases/setimmediate-window-open-crash/index.js b/spec-main/fixtures/crash-cases/setimmediate-window-open-crash/index.js
@@ -0,0 +1,21 @@
+const { app, BrowserWindow } = require('electron');
+
+function createWindow () {
+  const mainWindow = new BrowserWindow({
+    webPreferences: {
+      nodeIntegration: true,
+      contextIsolation: false,
+      nativeWindowOpen: true
+    }
+  });
+
+  mainWindow.on('close', () => {
+    app.quit();
+  });
+
+  mainWindow.loadFile('index.html');
+}
+
+app.whenReady().then(() => {
+  createWindow();
+});