popover: Unrealize when autohide prop changes

Changing the autohide property means the popover needs to be remapped.
Remapping may need user interaction, so lets just unrealize the popover
if the property changes, forcing the application to remap it should it
be shown again.

gtk/gtkpopover.c

@@ -1649,6 +1649,9 @@ gtk_popover_get_position (GtkPopover *popover)
  * A modal popover will grab the keyboard focus on it when being
  * displayed. Clicking outside the popover area or pressing Esc will
  * dismiss the popover.
+ *
+ * Called this function on an already showing popup with a new autohide value
+ * different from the current one, will cause the popup to be hidden.
  **/
 void
 gtk_popover_set_autohide (GtkPopover *popover,
@@ -1665,6 +1668,8 @@ gtk_popover_set_autohide (GtkPopover *popover,
 
   priv->autohide = autohide;
 
+  gtk_widget_unrealize (GTK_WIDGET (popover));
+
   g_object_notify_by_pspec (G_OBJECT (popover), properties[PROP_AUTOHIDE]);
 }