A new ioctl TIOCGDISPLAYS allow detecting which displays the terminal
has associated. The ability to set a keyboard layout can be detected
with tcgetblob kblayout.
Improve the user-space multi-monitor support while here.
The kernel now sets TERM rather than init(8).
This is a compatible ABI change riding on the previous commit's bump.
execl(3) and its variants use a sentinel to terminate the variadic
argument list, in the form of a null pointer constant of type pointer to
char. POSIX mandates that NULL is a null pointer constant of type
pointer to void, which is not of an equivalent type to that required by
execl(3) and its variants, resulting in undefined behaviour.
This commit casts all such instances of NULL to pointer to char type.
For consistency, it also adds const-qualification to any such instances
which had already been casted, and were not const-qualified.
I hereby relicense all my work on Sortix under the ISC license as below.
All Sortix contributions by other people are already under this license,
are not substantial enough to be copyrightable, or have been removed.
All imported code from other projects is compatible with this license.
All GPL licensed code from other projects had previously been removed.
Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors.
Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
This prevents a race condition where the console may still be rendering,
but the process may be able to get data on the screen faster, which results
in visual corruption as the two race.
