[client] override new behaviour in SDL 2.0.15 and disable xinput2

xinput2 is used to get touch interface events with the side effect of
consuming MotionNotify events which we use because of SDL2's inability
to correctly track the window size. Since we are not that intertested in
touch for our usecase, we just turn the events off again.

VERSION

@@ -1 +1 @@
-B1-95-g9846762991+1
+B1-96-g17e05c6fd5+1

client/CMakeLists.txt

@@ -46,6 +46,10 @@ pkg_check_modules(PKGCONFIG REQUIRED
 	x11
 )
 
+pkg_check_modules(PKGCONFIG_OPT
+	xi
+)
+
 execute_process(
 	COMMAND			cat ../VERSION
 	WORKING_DIRECTORY	${PROJECT_SOURCE_DIR}
@@ -63,12 +67,12 @@ get_filename_component(PROJECT_TOP "${PROJECT_SOURCE_DIR}/.." ABSOLUTE)
 include_directories(
 	${PROJECT_SOURCE_DIR}/include
 	${CMAKE_BINARY_DIR}/include
-	${PKGCONFIG_INCLUDE_DIRS}
+	${PKGCONFIG_INCLUDE_DIRS} ${PKGCONFIG_OPT_INCLUDE_DIRS}
 	${GMP_INCLUDE_DIR}
 )
 
 link_libraries(
-	${PKGCONFIG_LIBRARIES}
+	${PKGCONFIG_LIBRARIES} ${PKGCONFIG_OPT_LIBRARIES}
 	${GMP_LIBRARIES}
 	${CMAKE_DL_LIBS}
 	rt
@@ -94,7 +98,7 @@ add_subdirectory(fonts)
 add_subdirectory(decoders)
 
 add_executable(looking-glass-client ${SOURCES})
-target_compile_options(looking-glass-client PUBLIC ${PKGCONFIG_CFLAGS_OTHER})
+target_compile_options(looking-glass-client PUBLIC ${PKGCONFIG_CFLAGS_OTHER} ${PKGCONFIG_OPT_CFLAGS_OTHER})
 target_link_libraries(looking-glass-client
 	${EXE_FLAGS}
 	lg_common

client/src/main.c

@@ -35,6 +35,11 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <stdbool.h>
 #include <assert.h>
 
+#if SDL_VIDEO_DRIVER_X11_XINPUT2
+// because SDL2 sucks and we need to turn it off
+#include <X11/extensions/XInput2.h>
+#endif
+
 #include "common/debug.h"
 #include "common/crash.h"
 #include "common/KVMFR.h"
@@ -1331,6 +1336,25 @@ static int lg_run()
       // enable X11 events to work around SDL2 bugs
       SDL_EventState(SDL_SYSWMEVENT, SDL_ENABLE);
 
+#if SDL_VIDEO_DRIVER_X11_XINPUT2
+      // SDL2 bug, using xinput2 disables all motion notify events
+      // we really don't care about touch, so turn it off and go back
+      // to the default behaiovur.
+      XIEventMask xinputmask =
+      {
+        .deviceid = XIAllMasterDevices,
+        .mask     = 0,
+        .mask_len = 0
+      };
+
+      XISelectEvents(
+        state.wminfo.info.x11.display,
+        state.wminfo.info.x11.window,
+        &xinputmask,
+        1
+      );
+#endif
+
       Atom NETWM_BYPASS_COMPOSITOR = XInternAtom(
         state.wminfo.info.x11.display,
         "NETWM_BYPASS_COMPOSITOR",