[gtk/ebassi/mnemonic-label-remove] a11y: Fix removing mnemonic widgets

[Emmanuele Bassi <ebassi src gnome org>]

commit af0973c847128ef18a231aa133653413523861d0
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Dec 17 15:49:00 2020 +0000

    a11y: Fix removing mnemonic widgets
    
    We must not use the variadic arguments version with GList, as it expects
    a pointer to a GtkAccessible.

 gtk/gtkwidget.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 9204d62210..b26103e87b 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -9504,12 +9504,16 @@ gtk_widget_remove_mnemonic_label (GtkWidget *widget,
 
   if (new_list != NULL && new_list->data != NULL)
     {
-      GList *list;
+      GtkAccessibleRelation relation = GTK_ACCESSIBLE_RELATION_LABELLED_BY;
+      GValue value = G_VALUE_INIT;
 
-      list = gtk_widget_list_mnemonic_labels (widget);
-      gtk_accessible_update_relation (GTK_ACCESSIBLE (widget),
-                                      GTK_ACCESSIBLE_RELATION_LABELLED_BY, list,
-                                      -1);
+      /* The ATContext takes ownership of the GList returned by list_mnemonic_labels(),
+       * so we don't need to free it
+       */
+      gtk_accessible_relation_init_value (relation, &value);
+      g_value_set_pointer (&value, gtk_widget_list_mnemonic_labels (widget));
+      gtk_accessible_update_relation_value (GTK_ACCESSIBLE (widget), 1, &relation, &value);
+      g_value_unset (&value);
     }
   else
     {