This bug report was migrated from our old Bugzilla tracker.

These attachments are available in the static archive:

• x11events: ignore UnmapNotify events from XReparentWindow (0001-x11events-ignore-UnmapNotify-events-from-XReparentWi.patch, text/plain, 2020-10-17 20:11:44 +0000, 2514 bytes)

Reported in version: 2.0.12
Reported for operating system, platform: Linux, x86_64

Comments on the original bug report:

On 2020-10-10 14:32:46 +0000, Alberts Muktupāvels wrote:

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;

}

On 2020-10-12 16:27:58 +0000, Sam Lantinga wrote:

That seems reasonable, can you provide a tested and working patch? Can you also make sure that iconification is still detected correctly?

On 2020-10-17 20:11:44 +0000, Alberts Muktupāvels wrote:

Created attachment 4480
x11events: ignore UnmapNotify events from XReparentWindow

On 2020-10-17 20:16:32 +0000, Alberts Muktupāvels wrote:

(In reply to Sam Lantinga from comment # 1)

That seems reasonable, can you provide a tested and working patch? Can you
also make sure that iconification is still detected correctly?

Patch attached. Iconification seems to work as expected.

On 2020-10-20 00:27:20 +0000, Sam Lantinga wrote:

Patch added, thanks!
https://hg.libsdl.org/SDL/rev/204628027601