Re: SDL_EVDEV_do_text_input() may be too eager to find errors

After reducing my hacky patch to the minimum number of changes needed to to fix my setup, I uncovered another bug in SDL_EVDEV_is_console() that I accidentally fixed.  https://bugzilla.libsdl.org/show_bug.cgi?id=3546


When calling ioctl(fd, KDGKBTYPE, &type) in SDL_EVDEV_is_console(), we declare type as an 'int'.  This should be a 'char'.  The subsequent syscall, and kernel code, only writes the lower byte of the word. 

See: http://lxr.free-electrons.com/source/drivers/tty/vt/vt_ioctl.c?v=4.4#L399

ucval = KB_101;
ret = put_user(ucval, (char __user *)arg);

I've observed intermittent behavior related to this, and I can force an error condition by using an int initialized to 0xFFFFFFFF.  The resulting ioctl will set type to 0XFFFFFF02, and the conditional return in SDL_EVDEV_is_console() will fail.

Recommend changing to char, or masking off unused bits.

See attached patch for suggested fix.

-Rob

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