Avoid disabling off-the-record profile Hangouts extension with Qt 6.10.1

Otherwise this results in a crash, see #8785

qutebrowser/browser/webengine/webenginesettings.py

@@ -431,6 +431,17 @@ def _maybe_disable_hangouts_extension(profile: QWebEngineProfile) -> None:
         except AttributeError:
             return  # added in QtWebEngine 6.10
 
+        qtwe_versions = version.qtwebengine_versions(avoid_init=True)
+        if (
+            qtwe_versions.webengine == utils.VersionNumber(6, 10, 1)
+            and profile.isOffTheRecord()
+        ):
+            # WORKAROUND for https://github.com/qutebrowser/qutebrowser/issues/8785
+            log.misc.warning(
+                "Not disabling Hangouts extension on private profile to avoid "
+                "QtWebEngine crash with Qt 6.10.1")
+            return
+
         assert ext_manager is not None  # mypy
         for info in ext_manager.extensions():
             if info.id() == pakjoy.HANGOUTS_EXT_ID:

tests/end2end/test_invocations.py

@@ -21,6 +21,7 @@ import pytest
 from qutebrowser.qt.core import QProcess, QPoint
 
 from helpers import testutils
+from end2end.fixtures import quteprocess
 from qutebrowser.utils import qtutils, utils, version
 
 
@@ -612,6 +613,25 @@ def test_service_worker_workaround(
         assert not service_worker_dir.exists()
 
 
+def test_disable_hangouts_extension_crash(
+    quteproc_new: quteprocess.QuteProc,
+    request: pytest.FixtureRequest,
+    webengine_versions: version.WebEngineVersions,
+):
+    """Make sure disabling the Hangouts extension doesn't crash."""
+    args = _base_args(request.config) + [
+        '--temp-basedir',
+        '-s', 'qt.workarounds.disable_hangouts_extension', 'true',
+    ]
+    quteproc_new.start(args)
+    if webengine_versions.webengine == utils.VersionNumber(6, 10, 1):
+        line = quteproc_new.wait_for(message="Not disabling Hangouts extension *")
+        line.expected = True
+
+    quteproc_new.send_cmd(':quit')
+    quteproc_new.wait_for_quit()
+
+
 @pytest.mark.parametrize('store', [True, False])
 def test_cookies_store(quteproc_new, request, short_tmpdir, store):
     # Start test process