When a wlr_gamma_control client calls set_gamma, we allocate a LUT based
on the value returned from wlr_output_get_gamma_size at the time of the
call.
If the output is off and has no CRTC, such as if gamma changes in the
background while a display is disabled for idle reasons,
wlr_output_get_gamma_size returns 0. This leads to a zero-sized table,
which the drm backend interprets as a request to reset gamma tables to
their default.
Store the gamma size when the gamma control was created. Even if the
size changes, this is the size the client was sent and uses to create
the LUTs it sends.
Stop trying to maintain a per-file _POSIX_C_SOURCE. Instead,
require POSIX.1-2008 globally. A lot of core source files depend
on that already.
Some care must be taken on a few select files where we need a bit
more than POSIX. Some files need XSI extensions (_XOPEN_SOURCE) and
some files need BSD extensions (_DEFAULT_SOURCE). In both cases,
these feature test macros imply _POSIX_C_SOURCE. Make sure to not
define both these macros and _POSIX_C_SOURCE explicitly to avoid
POSIX requirement conflicts (e.g. _POSIX_C_SOURCE says POSIX.1-2001
but _XOPEN_SOURCE says POSIX.1-2008).
Additionally, there is one special case in render/vulkan/vulkan.c.
That file needs major()/minor(), and these are system-specific.
On FreeBSD, _POSIX_C_SOURCE hides system-specific symbols so we need
to make sure it's not defined for this file. On Linux, we can
explicitly include <sys/sysmacros.h> and ensure that apart from
symbols defined there the file only uses POSIX toys.
read advances the file description offset, and requires the client to
ensure that it is reset appropriately before the next gamma ramp
submission. As there is no event to indicate that wlroots finished
processing the new gamma ramp, this can result in a race between the
client seeking in the file and wlroots reading its content.
Use pread with a fixed offset instead.
Fixes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3655
When a new client comes in and tries to create a
zwlr_gamma_control_v1 object for an output which already has one,
we were destroying the old object and early-returning. The early
return causes the new object to not be set up properly: it's not
inserted in the list and doesn't get the gamma_size event.
Fix this by destroying the new object, and leave the old object
intact, which is what was the intent I think.
Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3605
Some globals are static and it doesn't make sense to destroy them before
the wl_display. For instance, wl_compositor should be created before the
display is started and shouldn't be destroyed.
For these globals, we can simplify the code by removing the destructor
and stop keeping track of wl_resources (these will be destroyed with the
wl_display by libwayland).
The documentation for wayland-server.h says:
> Use of this header file is discouraged. Prefer including
> wayland-server-core.h instead, which does not include the server protocol
> header and as such only defines the library PI, excluding the deprecated API
> below.
Replacing wayland-server.h with wayland-server-core.h allows us to drop the
WL_HIDE_DEPRECATED declaration.