mouse.c (event_reset) bug

[<tim...@en...>]

Hi !

While working on my wxwidgets terminal, I've just encountered the=20
following problem : typing "set terminal wxt" twice (without any plot=20
call between) gives a segmentation fault.

Indeed, it calls event_reset to cancel zoombox (in particular) as=20
explained in a comment in set.c
event_reset calls term->set_cursor but this fails as the terminal is not=20
initialiased at this stage. I don't think it's a problem from my=20
terminal, so I am proposing the attached patch to check for=20
term_initialised.

I hope this can be included !

Greetings,
Timoth=E9e Lecomte