Commit d0effadf68e9b7299fdade38f6bcef3d1a117a12
2021-07-31T15:56:30
x11: Don't let XRRSetScreenSize fire a BadMatch error. 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
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diff --git a/src/video/x11/SDL_x11modes.c b/src/video/x11/SDL_x11modes.c
index 09707a5..7dab9ff 100644
--- a/src/video/x11/SDL_x11modes.c
+++ b/src/video/x11/SDL_x11modes.c
@@ -995,6 +995,15 @@ X11_GetDisplayModes(_THIS, SDL_VideoDisplay * sdl_display)
}
}
+/* This catches an error from XRRSetScreenSize, as a workaround for now. */
+/* !!! FIXME: remove this later when we have a better solution. */
+static int (*PreXRRSetScreenSizeErrorHandler)(Display *, XErrorEvent *) = NULL;
+static int
+SDL_XRRSetScreenSizeErrHandler(Display *d, XErrorEvent *e)
+{
+ return (e->error_code == BadMatch) ? 0 : PreXRRSetScreenSizeErrorHandler(d, e);
+}
+
int
X11_SetDisplayMode(_THIS, SDL_VideoDisplay * sdl_display, SDL_DisplayMode * mode)
{
@@ -1040,7 +1049,17 @@ X11_SetDisplayMode(_THIS, SDL_VideoDisplay * sdl_display, SDL_DisplayMode * mode
mm_width = mode->w * DisplayWidthMM(display, data->screen) / DisplayWidth(display, data->screen);
mm_height = mode->h * DisplayHeightMM(display, data->screen) / DisplayHeight(display, data->screen);
+
+ /* !!! FIXME: this can get into a problem scenario when a window is
+ bigger than a physical monitor in a configuration where one screen
+ spans multiple physical monitors. A detailed reproduction case is
+ discussed at https://github.com/libsdl-org/SDL/issues/4561 ...
+ for now we cheat and just catch the X11 error and carry on, which
+ is likely to cause subtle issues but is better than outright
+ crashing */
+ PreXRRSetScreenSizeErrorHandler = X11_XSetErrorHandler(SDL_XRRSetScreenSizeErrHandler);
X11_XRRSetScreenSize(display, RootWindow(display, data->screen), mode->w, mode->h, mm_width, mm_height);
+ X11_XSetErrorHandler(PreXRRSetScreenSizeErrorHandler);
status = X11_XRRSetCrtcConfig (display, res, output_info->crtc, CurrentTime,
crtc->x, crtc->y, modedata->xrandr_mode, crtc->rotation,