When QtWebEngine shuts down, it calls pending callbacks, which means we access
an invalid 'settings' object when that happens. The stack would look something
like this:
0 QtWebEngineCore::WebEngineSettings::setAttribute(QtWebEngineCore::WebEngineSettings::Attribute, bool)
12 QtWebEngineCore::CallbackDirectory::invokeEmptyInternal<QVariant const&>(QtWebEnginePrivate::QWebEngineCallbackPrivateBase<QVariant const&>*)
14 QtWebEngineCore::CallbackDirectory::~CallbackDirectory()
19 QWebEnginePage::~QWebEnginePage()
If we instead get the settings from the view freshly, we get a RuntimeError from
PyQt telling us that it's dead. Not sure why it doesn't know about settings
being dead...
With that, we'd get a RuntimeError, which we can simply ignore as it doesn't
matter anyways if the tab is gone.
Fixes#3399
This fixes the following problems found in a review:
1. Manual modification of the asciidoc has been undone.
2. --output-to-tab has been renamed to the less verbose --output.
3. spawn_output has been changed to spawn-output in the url.
4. Erroneous newline in imports has been removed.
5. output in guiprocess.py has been marked private.
6. If there is no output for either stderr or stdout, say so.
7. Missing space in a text line was added.
8. Redundant initialising of an empty string removed.
While 64-bit values are allowed with QtWebKit/QNetworkDiskCache, QtWebEngine
only allows 32-bit values here. With the updated sip's strict overflow checking,
that means we get an exception when setting a too big value.
