shell-tray: Ensure that only a child can be added

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3818>
(cherry picked from commit 65fd43703b385aa9cdb3d8cb4e2d5e879613ea92)

diff --git a/src/shell-tray-icon.c b/src/shell-tray-icon.c
index 39204bfe66f9f693db561248a0586d80c80f6d0b..9b79c2be0da6be1acbcda4d36915d1c94425cb60 100644 (file)
--- a/src/shell-tray-icon.c
+++ b/src/shell-tray-icon.c
@@ -239,6 +239,7 @@ shell_tray_icon_set_child (ShellTrayIcon *tray_icon,
   MetaDisplay *display = shell_global_get_display (shell_global_get ());
 
   g_return_if_fail (tray_icon != NULL);
+  g_return_if_fail (tray_icon->tray_child == NULL);
   g_return_if_fail (tray_child != NULL);
 
   /* We do all this now rather than computing it on the fly later,