From the spec:
User agents should ensure, e.g. by means of an overlay, that the end user is
aware something is displayed fullscreen. User agents should provide a means of
exiting fullscreen that always works and advertise this to the user. This is
to prevent a site from spoofing the end user by recreating the user agent or
even operating system environment when fullscreen.
https://fullscreen.spec.whatwg.org/#security-and-privacy-considerations
There are a lot of problems and flakiness with using a real clipboard.
Instead we now have a :debug-set-fake-clipboard command to set a text, and use
logging when getting the contents.
Fixes#1285.
Previously we showed self.text in the __repr__ of MinimalLineEdit. This however
is a bad idea, because it exposes passwords to the debug log when the currently
focused widget is logged.
