Fix X11 LeaveWindow not raised with software rendering (#22120)

Author: MrJul

src/Avalonia.X11/X11Window.cs

@@ -605,13 +605,15 @@ private void OnEvent(ref XEvent ev)
             else if (ev.type == XEventName.MotionNotify)
                 MouseEvent(RawPointerEventType.Move, ref ev, ev.MotionEvent.state);
             else if (ev.type == XEventName.LeaveNotify)
-                MouseEvent(RawPointerEventType.LeaveWindow, ref ev, ev.CrossingEvent.state);
+            {
+                if (IsHandledLeaveEnterDetail(ev.CrossingEvent.detail))
+                {
+                    MouseEvent(RawPointerEventType.LeaveWindow, ref ev, ev.CrossingEvent.state);
+                }
+            }
             else if (ev.type == XEventName.EnterNotify)
             {
-                if (ev.CrossingEvent.detail is
-                    NotifyDetail.NotifyNonlinear or
-                    NotifyDetail.NotifyNonlinearVirtual or
-                    NotifyDetail.NotifyVirtual)
+                if (IsHandledLeaveEnterDetail(ev.CrossingEvent.detail))
                 {
                     MouseEvent(RawPointerEventType.Move, ref ev, ev.CrossingEvent.state);
                 }
@@ -758,6 +760,13 @@ NotifyDetail.NotifyNonlinearVirtual or
             }
         }
 
+        private static bool IsHandledLeaveEnterDetail(NotifyDetail detail)
+            => detail is
+                NotifyDetail.NotifyNonlinear or
+                NotifyDetail.NotifyNonlinearVirtual or
+                NotifyDetail.NotifyVirtual or
+                NotifyDetail.NotifyAncestor;
+
         private void HandleActivation(bool active)
         {
             if (active)

src/Avalonia.X11/XI2Manager.cs

@@ -296,7 +296,8 @@ private void OnEnterLeaveEvent(IXI2Client client, ref XIEnterLeaveEvent ev)
             var detail = ev.detail;
             if (detail != XiEnterLeaveDetail.XINotifyNonlinearVirtual &&
                 detail != XiEnterLeaveDetail.XINotifyNonlinear &&
-                detail != XiEnterLeaveDetail.XINotifyVirtual)
+                detail != XiEnterLeaveDetail.XINotifyVirtual &&
+                detail != XiEnterLeaveDetail.XINotifyAncestor)
                 return;
 
             var buttons = ParsedDeviceEvent.ParseButtonState(ev.buttons.MaskLen, ev.buttons.Mask);