Based on a patch by Jochen Schäfer <josch1710@live.de> :
The problem is, that in the initialization code uses the same structure for
desktop_mode and current_mode. See SDL_os2video.c:OS2_VideoInit():
stSDLDisplay.desktop_mode = stSDLDisplayMode;
stSDLDisplay.current_mode = stSDLDisplayMode;
...
stSDLDisplayMode.driverdata = pDisplayData;
Then, if you call GetDisplayModes, current_mode will added to the modes
list, with the same driverdata pointer to desktop_mode.
SDL_AddDisplayMode( display, &display->current_mode );
When VideoQuit gets called, first the modes list gets freed including the
driverdata, the desktop_mode gets freed. See SDL_video.c:SDL_VideoQuit():
for (j = display->num_display_modes; j--;) {
SDL_free(display->display_modes[j].driverdata);
display->display_modes[j].driverdata = NULL;
}
SDL_free(display->display_modes);
display->display_modes = NULL;
SDL_free(display->desktop_mode.driverdata);
display->desktop_mode.driverdata = NULL;
So, the display_modes[j].driverdata gets freed, but desktop_mode->driverdata
points to the same memory, but is not NULL'ed. When desktop_mode->driverdata
gets freed the memory is already freed, and libcx crashes the application on
SDL_Quit.
This adds SDL_SetWindowKeyboardGrab(), SDL_GetWindowKeyboardGrab(),
SDL_SetWindowMouseGrab(), SDL_GetWindowMouseGrab(), and new
SDL_WINDOW_KEYBOARD_GRABBED flag. It also updates the test harness to exercise
this functionality and makes a minor fix to X11 that I missed in
https://hg.libsdl.org/SDL/rev/02a2d609369b
To fit in with this new support, SDL_WINDOW_INPUT_CAPTURE has been renamed to
SDL_WINDOW_MOUSE_CAPTURE with the old name remaining as an alias for backwards
compatibility with older code.
- SDL_video.c (SDL_ShowMessageBox): replace messageboxdata, set title
or message field to "" if either of them is NULL.
- SDL_video.c (SDL_ShowSimpleMessageBox): set title or message to ""
if either of them is NULL for EMSCRIPTEN builds.
- SDL_bmessagebox.cc: add empty string check along with NULL check for
title and message fields.
- SDL_windowsmessagebox.c (AddDialogString): remove NULL string check
- SDL_windowsmessagebox.c (AddDialogControl): add empty string check
along with the NULL check.
- SDL_x11messagebox.c: revert commit 677c4cd68069
- SDL_os2messagebox.c: revert commit 2c2a489d76e7
- test/testmessage.c: Add NULL title and NULL message tests.
Add a minimal my_gradd.h containing structures and constants only used
by SDL_os2vman.c -- based on public knowledge from around the internet
including pages from http://www.osfree.org and http://www.edm2.com .
- video: VideoBootStrap->available() is gone.
- thread: all important SDL_CreateThread internal data now put into
struct SDL_Thread: changes to SDL_SYS_CreateThread().
- events / video: SDL_SetDoubleClickTime() removed -- functionality
moved to SDL_mouse.c:SDL_MouseDoubleClickTimeChanged().
- video: struct SDL_VideoDevice-> CreateWindow and CreateWindowFrom
members renamed to CreateSDLWindow and CreateSDLWindowFrom
