Handle _chromium_version without webenginesettings module

This can happen when we intend to start with the QtWebEngine backend (so
_chromium_version will get called), but we don't actually have the QtWebEngine
module available. If there's a crash while the backendproblem dialog is shown,
this results in webenginesettings being None here.

2 files changed, 9 insertions, 2 deletions

diff --git a/qutebrowser/utils/version.py b/qutebrowser/utils/version.py
index 6f8628daf..50a00c20b 100644
--- a/qutebrowser/utils/version.py
+++ b/qutebrowser/utils/version.py
@@ -364,6 +364,9 @@ def _chromium_version() -> str:
     Also see https://www.chromium.org/developers/calendar
     and https://chromereleases.googleblog.com/
     """
+    if webenginesettings is None:
+        return 'unavailable'  # type: ignore
+
     if webenginesettings.parsed_user_agent is None:
         webenginesettings.init_user_agent()
         assert webenginesettings.parsed_user_agent is not None
diff --git a/tests/unit/utils/test_version.py b/tests/unit/utils/test_version.py
index 043621667..d1f692540 100644
--- a/tests/unit/utils/test_version.py
+++ b/tests/unit/utils/test_version.py
@@ -863,8 +863,12 @@ def test_chromium_version(monkeypatch, caplog):
     version.webenginesettings._init_user_agent_str(
         _QTWE_USER_AGENT.format(ver))
 
-    with caplog.at_level(logging.ERROR):
-        assert version._chromium_version() == ver
+    assert version._chromium_version() == ver
+
+
+def test_chromium_version_no_webengine(monkeypatch):
+    monkeypatch.setattr(version, 'webenginesettings', None)
+    assert version._chromium_version() == 'unavailable'
 
 
 def test_chromium_version_prefers_saved_user_agent(monkeypatch):