Crash after toggling ApplicationManagerWindow.visible

Changing the visible property of a (visible) ApplicationManagerWindow to false and back to true again in one slot causes appman to crash. This only happens in multi-process mode. To reproduce, apply the following patch to the minidesk example:

— a/examples/minidesk/apps/tld.minidesk.app1/app1.qml
+++ b/examples/minidesk/apps/tld.minidesk.app1/app1.qml
@@ -81,14 +81,15 @@ ApplicationManagerWindow {
                     rotation.pause();
                     root.setWindowProperty("rotation", parent.rotation);
                 }
-                popUp.visible = !popUp.visible;
+                popUp.visible = false;
+                popUp.visible = true;
             }
         }
     }
 
     ApplicationManagerWindow {
         id: popUp
-        visible: false
+        visible: true
         color: "lightcoral"
 
         Text {