[gtk/ebassi/new-a11y: 67/71] a11y: Update labelled-by when setting mnemonic labels

[Emmanuele Bassi <ebassi src gnome org>]

commit 4c47fc511b21dae21894935718285c49816dafe8
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Jul 22 13:11:28 2020 +0100

    a11y: Update labelled-by when setting mnemonic labels
    
    The ARIA labelled-by attribute behaves the same way as the mnemonic
    labels in GTK.

 gtk/gtkwidget.c | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 3d189002f6..b68e63ae67 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -8960,6 +8960,10 @@ gtk_widget_add_mnemonic_label (GtkWidget *widget,
 
   g_object_set_qdata_full (G_OBJECT (widget), quark_mnemonic_labels,
                           new_list, (GDestroyNotify) g_slist_free);
+
+  gtk_accessible_update_relation (GTK_ACCESSIBLE (widget),
+                                  GTK_ACCESSIBLE_RELATION_LABELLED_BY, new_list,
+                                  -1);
 }
 
 /**
@@ -8988,6 +8992,10 @@ gtk_widget_remove_mnemonic_label (GtkWidget *widget,
   if (new_list)
     g_object_set_qdata_full (G_OBJECT (widget), quark_mnemonic_labels,
                             new_list, (GDestroyNotify) g_slist_free);
+
+  gtk_accessible_update_relation (GTK_ACCESSIBLE (widget),
+                                  GTK_ACCESSIBLE_RELATION_LABELLED_BY, new_list,
+                                  -1);
 }
 
 /**