We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

https://github.com/SDL-mirror/SDL/blob/master/src/video/x11/SDL_x11events.c#L949-L956

SDL receiving UnmapNotify event assumes that window has been iconified. This assumption seems wrong... For example UnmapNotify event is also sent when window is reparented, see https://tronche.com/gui/x/xlib/window-and-session-manager/XReparentWindow.html.

This causes problems when using SDL applications with Metacity 3.36+. Metacity now removes decorations when windows are fullscreen.

Perhaps SDL could check if next event is ReparentNotify and not dispatch UnmapNotify in that case? Something like this:

XEvent ev;
if (X11_XCheckIfEvent(display, &ev, &isReparentNotify, (XPointer)&xevent.xunmap))
  X11_XCheckIfEvent(display, &ev, &isMapNotify, (XPointer)&xevent.xunmap);
else
  X11_DispatchUnmapNotify(data);


static Bool isMapNotify(Display *dpy, XEvent *ev, XPointer unmap)
{
    XUnmapEvent *event;

    event = (XUnmapEvent*) unmap;

    return ev->type == MapNotify &&
        ev->xmap.window == event->window &&
        ev->xmap.serial == event->serial;
}

static Bool isReparentNotify(Display *dpy, XEvent *ev, XPointer unmap)
{
    XUnmapEvent *event;

    event = (XUnmapEvent*) unmap;

    return ev->type == ReparentNotify &&
        ev->xreparent.window == event->window &&
        ev->xreparent.serial == event->serial;
}