expecially by the mnemonic of another label that targets it.
https://gitlab.gnome.org/GNOME/gtk/-/issues/4927
see also https://bugs.documentfoundation.org/show_bug.cgi?id=137748
if (self->mnemonic_widget)
return gtk_widget_mnemonic_activate (self->mnemonic_widget, group_cycling);
+ /* Not a label for something else, but is selectable, so set focus into
+ * the label itself.
+ */
+ if (gtk_label_get_selectable (self) && gtk_widget_get_focusable (widget))
+ return gtk_label_grab_focus (widget);
+
/* Try to find the widget to activate by traversing the
* widget's ancestry.
*/