Some Wayland compositors send (0,0) as "suggested" configure event sizes to
indicate that the client has to decide on its own which sizes to used. This
is commonly done when restoring from maximised, fullscreen or tiles states
to fullscreen.
We now store the last known floating states in a new set of variables and
restore them when we receive such a (0,0) configure event.
From the vfork manpage:
> The vfork() function has the same effect as fork(2), except that
> the behavior is undefined if the process created by vfork() either
> modifies any data other than a variable of type pid_t used to store
> the return value from vfork(), or returns from the function in which
> vfork() was called, or calls any other function before successfully
> calling _exit(2) or one of the exec(3) family of functions.
unsetenv is still called inside a child process, so it does not
influence the rest of the application.
This fixes a crash on pressing keyboard button when compositor sends
zero as repeat rate, indicating that key repeat should be disabled.
From Wayland protocol spec:
> Negative values for either rate or delay are illegal. A rate of zero
> will disable any repeating (regardless of the value of delay).
This is a workaround and not a proper fix, but this is possibly complicated,
and possibly a corner case, so this will do for 2.0.16, if not the
foreseeable future.
Reference issue #4561
When we removed the OpenGL resize workaround it introduced a problem for
fullscreen windows in particular: When leaving fullscreen we tried to send a
resize event, but UpdateFullscreenMode would send a SIZE_CHANGED immediately
after, deleting our resize event and causing the following configure event's
resize to be ignored. This timing issue resulted in fullscreen windows not
being resized at all when becoming a floating window.
By always forcing resize events from configure events, we ensure that RESIZED
always makes it through. SetWindowSize-type changes should be unaffected as
they do not fire configure events.
The RenderDrawLinesWithRects and RenderDrawLinesWithRectsF functions can
sometimes call QueueCmdFillRects() with the data pointed to by frects
uninitialised. This can occur if none of the lines can be replaced with
rects, in which case the frects array is empty, and nrects is 0.
gcc 10.3.0 will detect this possibility, and print a warning like:
/home/david/Development/SDL/src/render/SDL_render.c: In function 'RenderDrawLinesWithRectsF':
/home/david/Development/SDL/src/render/SDL_render.c:2725:15: warning: '<unknown>' may be used uninitialized [-Wmaybe-uninitialized]
2725 | retval += QueueCmdFillRects(renderer, frects, nrects);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/david/Development/SDL/src/render/SDL_render.c:499:1: note: by argument 2 of type 'const SDL_FRect *' to 'QueueCmdFillRects' declared here
499 | QueueCmdFillRects(SDL_Renderer *renderer, const SDL_FRect * rects, const int count)
| ^~~~~~~~~~~~~~~~~
This is harmless, because when this is uninitialised, nrects is always
0, so QueueCmdFillRects() does nothing anyway. We therefore can work
around this by only calling QueueCmdFillRects() when nrects is nonzero.
Somewhat impressively, gcc recognises that this is now safe.
This is needed to support CHERI, and thus Arm's experimental Morello
prototype, where pointers are implemented using unforgeable capabilities
that include bounds and permissions metadata to provide fine-grained
spatial and referential memory safety, as well as revocation by sweeping
memory to provide heap temporal memory safety.
The C standard does not guarantee that if two pointers compare equal
they are the same pointer, as C pointers have a notion of provenance,
and compilers have been known to exploit this during optimisation. For
CHERI, this becomes even more important, as in-place expansion can
result in realloc returning a capability to the same address but with
increased capability bounds, and so reusing the old capability will trap
trying to access outside the bounds of the original allocation.
In the case that ptr == mem, memdiff and ptrdiff should still be equal,
so the only overhead is a small amount of pointer arithmetic and a store
of the new pointer (which is required per the C standard in order to not
be undefined behaviour when next loaded).
This also fixes the calculation of oldmem to use uintptr_t rather than
size_t as casting the pointer to size_t on CHERI will strip the
capability metadata, including the validity tag, with the subsequent
cast back to void * resulting in a null-derived capability whose
validity tag is clear and thus cannot be dereferenced without trapping.
This is needed to support CHERI, and thus Arm's experimental Morello
prototype, where pointers are implemented using unforgeable capabilities
that include bounds and permissions metadata to provide fine-grained
spatial and referential memory safety, as well as revocation by sweeping
memory to provide heap temporal memory safety.
On most systems (anything with a flat memory hierarchy rather than using
segment-based addressing), size_t and uintptr_t are the same type.
However, on CHERI, size_t is just an integer offset, whereas uintptr_t
is still a capability as described above. Casting a pointer to size_t
will strip the metadata and validity tag, and casting from size_t to a
pointer will result in a null-derived capability whose validity tag is
not set, and thus cannot be dereferenced without faulting.
The audio and cursor casts were harmless as they intend to stuff an
integer into a pointer, but using uintptr_t is the idiomatic way to do
that and silences our compiler warnings (which our build tool makes
fatal by default as they often indicate real problems). The iconv and
egl casts were true positives as SDL_iconv_t and iconv_t are pointer
types, as is NativeDisplayType on most OSes, so this would have trapped
at run time when using the round-tripped pointers. The gles2 casts were
also harmless; the OpenGL API defines this argument to be a pointer type
(and uses the argument name "pointer"), but it in fact represents an
integer offset, so like audio and cursor the additional idiomatic cast
is needed to silence the warning.
When choosing an X11 Visual for a window based on its GLX capabilities, first
try glXChooseFBConfig (if available) before falling back to glXChooseVisual.
This normally does not make a difference because most GLX drivers create a
Visual for every GLXFBConfig, exposing all of the same capabilities.
For GLX render offload configurations (also know as "PRIME") where one GPU is
providing GLX rendering support for windows on an X screen running on a
different GPU, the GPU doing the offloading needs to use the Visuals that were
created by the host GPU's driver rather than being able to add its own. This
means that there may be fewer Visuals available for all of the GLXFBConfigs the
guest driver wants to expose. In order to handle that situation, the NVIDIA GLX
driver creates many GLXFBConfigs that map to the same Visual when running in a
render offload configuration.
This can result in a glXChooseVisual request failing to find a supported Visual
when there is a GLXFBConfig for that configuration that would have worked. For
example, when the game "Unnamed SDVX Clone" [1] tries to create a configuration
with multisample, glXChooseVisual fails because the Visual assigned to the
multisample GLXFBConfigs is shared with the GLXFBConfigs without multisample.
Avoid this problem by using glXChooseFBConfig, when available, to find a
GLXFBConfig with the requested capabilities and then using
glXGetVisualFromFBConfig to find the corresponding X11 Visual. This allows the
game to run, although it doesn't make me any better at actually playing it...
Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Fixes: https://forums.developer.nvidia.com/t/prime-run-cannot-create-window-x-glxcreatecontext/180214
[1] https://github.com/Drewol/unnamed-sdvx-clone
As of [1], SDL now compiles with a warning in SDL_waylandevents.c on
32-bit systems under gcc 10.3.0:
/tmp/SDL/src/video/wayland/SDL_waylandevents.c: In function 'seat_handle_capabilities':
/tmp/SDL/src/video/wayland/SDL_waylandevents.c:958:22: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
958 | SDL_AddTouch((SDL_TouchID)seat, SDL_TOUCH_DEVICE_DIRECT, "wayland_touch");
| ^
/tmp/SDL/src/video/wayland/SDL_waylandevents.c:964:22: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
964 | SDL_DelTouch((SDL_TouchID)seat);
| ^
This is due to SDL_TouchID always being 32-bit, but seat being a pointer
which is (obviously) only 32-bit on 32-bit systems. The conversion is
therefore harmless, so silence it with an extra cast via intptr_t.
This is what the cocoa backend does (and is similar to what the Win32
backend does, except with size_t).
Fixes: 03c19efbd1 ("Added support for multiple seats with touch input on Wayland")
[1]: 03c19efbd1
When wayland is not dynamically loaded (--enable-wayland-shared=no)
libdecor.h is not included unless SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC
is set, so it fails to build. We can't simply move the libdecor.h
include above the #ifdef SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC block, as
libdecor.h itself #includes wayland headers we need to replace with
#defines. Instead, duplicate the #include.
Fixes https://github.com/libsdl-org/SDL/issues/4543
Note that this doesn't fix any of the underlying issues of libdecor
being treated as part of wayland, it just fixes the build. A better
solution would probably be to decouple the wayland dynamic loading
from the libdecor dynamic loading completely, though that is a lot
more work...
Each window can have at most one zxdg toplevel decoration, but as of
[1], we accidentally create two. (If libdecor is not in use). This
causes wayland windows with server-side decorations (e.g. on KDE/KWin)
to crash with the message:
zxdg_decoration_manager_v1@7: error 1: decoration has been already constructed
This extra zxdg_decoration_manager_v1.get_toplevel_decoration() call was
introduced while deprecating wl-shell and xdg-shell-stable[1] support,
and possibly was a bad interaction with [2], which moved the decoration
creation around.
Fixes: 6aae5b44f8 ("Remove wl-shell and xdg-shell-unstable-v6 support (#4323)")
[1]: https://github.com/libsdl-org/SDL/pull/4323
[2]: https://github.com/libsdl-org/SDL/pull/4374
