Merge pull request #57658 from NousResearch/bb/readtitle-race

fix(desktop): guard link-title readTitle against destroyed windows

apps/desktop/electron/link-title-window.cjs

@@ -49,4 +49,23 @@ function guardLinkTitleSession(partitionSession) {
   }
 }
 
-module.exports = { createLinkTitleWindow, guardLinkTitleSession, linkTitleWindowOptions }
+// Read the page title from a title-fetch window. Callers schedule this from
+// timers that can fire after finish() destroys the window, so every access must
+// guard isDestroyed and swallow Electron's "Object has been destroyed" throws.
+function readLinkTitleWindowTitle(window) {
+  try {
+    if (!window || window.isDestroyed()) return ''
+    const contents = window.webContents
+    if (!contents || contents.isDestroyed()) return ''
+    return contents.getTitle() || ''
+  } catch {
+    return ''
+  }
+}
+
+module.exports = {
+  createLinkTitleWindow,
+  guardLinkTitleSession,
+  linkTitleWindowOptions,
+  readLinkTitleWindowTitle
+}

apps/desktop/electron/link-title-window.test.cjs

@@ -1,7 +1,12 @@
 const assert = require('node:assert/strict')
 const test = require('node:test')
 
-const { createLinkTitleWindow, guardLinkTitleSession, linkTitleWindowOptions } = require('./link-title-window.cjs')
+const {
+  createLinkTitleWindow,
+  guardLinkTitleSession,
+  linkTitleWindowOptions,
+  readLinkTitleWindowTitle
+} = require('./link-title-window.cjs')
 
 function makeFakeBrowserWindow() {
   const calls = { audioMuted: [] }
@@ -66,3 +71,44 @@ test('guardLinkTitleSession cancels downloads triggered by the title-fetch windo
 test('guardLinkTitleSession is a no-op when session.on throws', () => {
   assert.doesNotThrow(() => guardLinkTitleSession({ on() { throw new Error() } }))
 })
+
+test('readLinkTitleWindowTitle returns empty for missing or destroyed windows', () => {
+  assert.equal(readLinkTitleWindowTitle(null), '')
+  assert.equal(readLinkTitleWindowTitle(undefined), '')
+  assert.equal(readLinkTitleWindowTitle({ isDestroyed: () => true }), '')
+})
+
+test('readLinkTitleWindowTitle returns empty when webContents is destroyed', () => {
+  const window = {
+    isDestroyed: () => false,
+    webContents: { isDestroyed: () => true, getTitle: () => 'Should Not Read' }
+  }
+
+  assert.equal(readLinkTitleWindowTitle(window), '')
+})
+
+test('readLinkTitleWindowTitle swallows getTitle throws after teardown', () => {
+  const window = {
+    isDestroyed: () => false,
+    webContents: {
+      isDestroyed: () => false,
+      getTitle: () => {
+        throw new Error('Object has been destroyed')
+      }
+    }
+  }
+
+  assert.equal(readLinkTitleWindowTitle(window), '')
+})
+
+test('readLinkTitleWindowTitle returns trimmed page title', () => {
+  const window = {
+    isDestroyed: () => false,
+    webContents: {
+      isDestroyed: () => false,
+      getTitle: () => 'Example Domain'
+    }
+  }
+
+  assert.equal(readLinkTitleWindowTitle(window), 'Example Domain')
+})

apps/desktop/electron/main.cjs

@@ -36,7 +36,11 @@ const {
   SESSION_WINDOW_MIN_WIDTH
 } = require('./session-windows.cjs')
 const { canImportHermesCli, verifyHermesCli } = require('./backend-probes.cjs')
-const { createLinkTitleWindow, guardLinkTitleSession } = require('./link-title-window.cjs')
+const {
+  createLinkTitleWindow,
+  guardLinkTitleSession,
+  readLinkTitleWindowTitle
+} = require('./link-title-window.cjs')
 const { probeGatewayWebSocket } = require('./gateway-ws-probe.cjs')
 const { adoptServedDashboardToken } = require('./dashboard-token.cjs')
 const { waitForDashboardPortAnnouncement } = require('./backend-ready.cjs')
@@ -3557,13 +3561,13 @@ function runRenderTitleJob(rawUrl) {
       return finish('')
     }
 
-    const readTitle = () => window?.webContents?.getTitle?.() || ''
+    const finishWithTitle = () => finish(readLinkTitleWindowTitle(window))
     const scheduleGrace = () => {
       if (graceTimer) clearTimeout(graceTimer)
-      graceTimer = setTimeout(() => finish(readTitle()), RENDER_TITLE_GRACE_MS)
+      graceTimer = setTimeout(finishWithTitle, RENDER_TITLE_GRACE_MS)
     }
 
-    hardTimer = setTimeout(() => finish(readTitle()), RENDER_TITLE_TIMEOUT_MS)
+    hardTimer = setTimeout(finishWithTitle, RENDER_TITLE_TIMEOUT_MS)
 
     window.webContents.setUserAgent(TITLE_USER_AGENT)
     window.webContents.on('page-title-updated', scheduleGrace)