[gtk/gtk-4-2: 90/91] dragsource: Keep the source alive long enough

[Matthias Clasen <matthiasc src gnome org>]

commit 2f921ab66795c947d75ab269412f9c73abf88508
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon May 3 17:00:17 2021 -0400

    dragsource: Keep the source alive long enough
    
    When a drop causes the event controller to be finalized
    (directly or indirectly), we end up segfaulting while
    trying to wrap up the drag operation. So, keep a reference
    on the GtkDragSource from when the drag begins to when
    it is done.
    
    This fixes a crash in gnome-todo when dragging tasks.

 gtk/gtkdragsource.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gtk/gtkdragsource.c b/gtk/gtkdragsource.c
index cd6c33a7fa..a75f60f5c2 100644
--- a/gtk/gtkdragsource.c
+++ b/gtk/gtkdragsource.c
@@ -470,6 +470,7 @@ drag_end (GtkDragSource *source,
 
   gdk_drag_drop_done (source->drag, success);
   g_clear_object (&source->drag);
+  g_object_unref (source);
 }
 
 static void
@@ -593,6 +594,9 @@ gtk_drag_source_drag_begin (GtkDragSource *source)
 
   gtk_drag_source_ensure_icon (source, source->drag);
 
+  /* Keep the source alive until the drag is done */
+  g_object_ref (source);
+
   g_signal_connect (source->drag, "dnd-finished",
                     G_CALLBACK (gtk_drag_source_dnd_finished_cb), source);
   g_signal_connect (source->drag, "cancel",