When our keyboard grab hook is installed, GetKeyState() will return 0 for the
GUI keys even when they are pressed. This leads to spurious key up events when
holding down the GUI keys and the inability to use any key combos involving
those modifier keys.
This fixes a compile warning — and possible invalid memory read —
introduced in 9c03d255 ("Add back X11 legacy WM_NAME encodings"), which
was part of PR #5029, fixing Bug #4924.
The issue is with one of the added warnings in X11_GetWindowTitle().
Basically, the "title" variable passed to SDL_LogError() hasn't been
initialised yet: we could pass propdata in directly, but it's better to
move the SDL_LogError() call until after title is set, IMHO.
This fixes the following warning from gcc (SUSE Linux) 11.2.1:
In file included from /home/david/Development/SDL/src/video/x11/../../SDL_internal.h:45,
from /home/david/Development/SDL/src/video/x11/SDL_x11window.c:21:
/home/david/Development/SDL/src/video/x11/SDL_x11window.c: In function 'X11_GetWindowTitle':
/home/david/Development/SDL/src/video/x11/../../dynapi/SDL_dynapi_overrides.h:33:22: warning: '%s' directive argument is null [-Wformat-overflow=]
33 | #define SDL_LogDebug SDL_LogDebug_REAL
/home/david/Development/SDL/src/video/x11/SDL_x11window.c:720:13: note: in expansion of macro 'SDL_LogDebug'
720 | SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "Failed to convert WM_NAME title expecting UTF8! Title: %s", title);
| ^~~~~~~~~~~~
Closes#4924.
Based on patches of the past, such as this work by James Cloos in July
2010:
d7d98751b7,
as well as code comments in the Perl module X11::Protocol::WM
(https://metacpan.org/pod/X11::Protocol::WM) and even the code to Xlib
itself, which taught me that we should never have been using
`XStoreName`, all it does is call `XChangeProperty`, hardcoded to
`XA_STRING`!
What can I say, when the task is old school, the sources are too 😂
macOS 10.6 has some touch NSEvents which do not have a subtype
(Begin/EndGesture, Magnify, Rotate, Swipe) and cause an uncaught
exception which triggers SIGABRT and the program exits.
As it is, none of the macOS 10.6 touch events are detected as a
trackpad (including Gesture due to using different subtypes).
Case fallthrough warnings can be suppressed using the __fallthrough__
compiler attribute. Unfortunately, not all compilers have this
attribute, or even have __has_attribute to check if they have the
__fallthrough__ attribute. [[fallthrough]] is also available in C++17
and the next C2x, but not everyone uses C++17 or C2x.
So define the SDL_FALLTHROUGH macro to deal with those problems - if we
are using C++17 or C2x, it expands to [[fallthrough]]; else if the
compiler has __has_attribute and has the __fallthrough__ attribute, then
it expands to __attribute__((__fallthrough__)); else it expands to an
empty statement, with a /* fallthrough */ comment (it's a do {} while
(0) statement, because users of this macro need to use a semicolon,
because [[fallthrough]] and __attribute__((__fallthrough__)) require a
semicolon).
Clang before Clang 10 and GCC before GCC 7 have problems with using
__attribute__ as a sole statement and warn about a "declaration not
declaring anything", so fall back to using the /* fallthrough */ comment
if we are using those older compiler versions.
Applications using SDL are also free to use this macro (because it is
defined in begin_code.h).
All existing /* fallthrough */ comments have been replaced with this
macro. Some of them were unnecessary because they were the last case in
a switch; using SDL_FALLTHROUGH in those cases would result in a compile
error on compilers that support __fallthrough__, for having a
__attribute__((__fallthrough__)) statement that didn't immediately
precede a case label.
