dnd: Fix lifecycle issues with widgets as drag icons

The documentation clearly says that the widget is not destroyed,
but we were in fact failing to keep it alive, since it was still
a child or the icon_window when we destroy that. Fix this by
reparenting the icon_widget out before. Also, deal with the
possibility that the application might destroy the widget
halfway through, for whatever reason.

diff --git a/gtk/gtkdnd.c b/gtk/gtkdnd.c
index 71913b03d9d8689e1152f32794fc1464c4a7d40f..d0b391c50cca95d32bd83368538d600052f5722a 100644 (file)
--- a/gtk/gtkdnd.c
+++ b/gtk/gtkdnd.c
@@ -2011,6 +2011,13 @@ gtk_drag_begin (GtkWidget     *widget,
                                   actions, button, event, -1, -1);
 }
 
+static void
+icon_widget_destroyed (GtkWidget         *widget,
+                       GtkDragSourceInfo *info)
+{
+  g_clear_object (&info->icon_widget);
+}
+
 static void
 gtk_drag_set_icon_widget_internal (GdkDragContext *context,
                                    GtkWidget      *widget,
@@ -2041,6 +2048,8 @@ gtk_drag_set_icon_widget_internal (GdkDragContext *context,
   if (!widget)
     goto out;
 
+  g_signal_connect (widget, "destroy", G_CALLBACK (icon_widget_destroyed), info);
+
   gdk_drag_context_set_hotspot (context, hot_x, hot_y);
 
   if (!info->icon_window)
@@ -2715,11 +2724,15 @@ gtk_drag_remove_icon (GtkDragSourceInfo *info)
       widget = info->icon_widget;
       info->icon_widget = NULL;
 
+      g_signal_handlers_disconnect_by_func (widget, icon_widget_destroyed, info);
+
       gtk_widget_hide (widget);
       gtk_widget_set_opacity (widget, 1.0);
 
       if (info->destroy_icon)
         gtk_widget_destroy (widget);
+      else
+        gtk_container_remove (GTK_CONTAINER (info->icon_window), widget);
 
       g_object_unref (widget);
     }