Re: master ee6e4bc525: Update device-specific grab during drag-and-drop

[Po Lu]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> This (or something other change in this area) leads to the following
> warnings in an --with-x-toolkit=no build on the current Ubuntu:
>
> xterm.c: In function 'handle_one_xevent':
> xterm.c:21537:40: warning: potential null pointer dereference 
> [-Wnull-dereference]
> 21537 |                           device->grab &= ~(1 << xev->detail);
>       |                           ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
> xterm.c:21537:40: warning: potential null pointer dereference 
> [-Wnull-dereference]
> 21537 |                           device->grab &= ~(1 << xev->detail);
>       |                                        ^~
>
> I haven't checked whether it's a correct warning or not.

I guess it can happen if another bug makes Emacs "forget" devices, but I
fixed all of those at the end of May.

So for consistency I would enclose it with if (device), but I don't
think the NULL dereference can actually happen in reality.