Related: tdf#125479 menu item might be empty

Change-Id: I1b82e6495dcc64fde58498036f02f779a657301b
Reviewed-on: https://gerrit.libreoffice.org/72981
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/unx/gtk3/gtk3gtkinst.cxx

@@ -8685,6 +8685,8 @@ static void disable_area_apply_attributes_cb(GtkWidget* pItem, gpointer userdata
 {
     GtkMenuItem* pMenuItem = GTK_MENU_ITEM(pItem);
     GtkWidget* child = gtk_bin_get_child(GTK_BIN(pMenuItem));
+    if (!child)
+        return;
     GtkCellView* pCellView = GTK_CELL_VIEW(child);
     GtkCellLayout* pCellLayout = GTK_CELL_LAYOUT(pCellView);
     GtkCellArea* pCellArea = gtk_cell_layout_get_area(pCellLayout);