bug#25887: 26.0.50; Exiting fullscreen

[martin rudalics]

> I can do that, but since I don't know this code, can you provide a
> suitable commit message?  Perhaps Dani can also confirm this fix before
> it's installed.

I managed to install it now.

> I updated before trying your fix, and "make" failed, so I resorted to
> bootstrapping, since it only takes an hour or so on my machine. ;-)

These days I'm getting again and again failures I never got earlier
about something missing with cl-lib or cl-generic, invalid bytecode,
undefined functions and so on.

martin