[gtk+] Make _gdk_window_process_updates_recurse reentrancy safe

[Alexander Larsson <alexl src gnome org>]

commit 9f822431970b9744f0184ae2d9e9977f607ffe4e
Author: Alexander Larsson <alexl redhat com>
Date:   Thu Aug 13 17:00:00 2009 +0200

    Make _gdk_window_process_updates_recurse reentrancy safe
    
    Apps may change the window hierarchy while recursing over it by
    destroying windows from the expose event handler. We need to copy
    the children list and ref all the children while recursing.
    
    This fixes some crashers in gedit (bug #589367, bug #591434)

 gdk/gdkwindow.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index ba4ad63..e9c5512 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -4751,17 +4751,21 @@ _gdk_window_process_updates_recurse (GdkWindow *window,
   GdkWindowObject *child;
   GdkRegion *child_region;
   GdkRectangle r;
-  GList *l;
+  GList *l, *children;
 
   if (gdk_region_empty (expose_region))
     return;
 
+  /* Make this reentrancy safe for expose handlers freeing windows */
+  children = g_list_copy (private->children);
+  g_list_foreach (children, g_object_ref, NULL);
+
   /* Iterate over children, starting at topmost */
-  for (l = private->children; l != NULL; l = l->next)
+  for (l = children; l != NULL; l = l->next)
     {
       child = l->data;
 
-      if (!GDK_WINDOW_IS_MAPPED (child) || child->input_only || child->composited)
+      if (child->destroyed || !GDK_WINDOW_IS_MAPPED (child) || child->input_only || child->composited)
 	continue;
 
       /* Ignore offscreen children, as they don't draw in their parent and
@@ -4799,6 +4803,9 @@ _gdk_window_process_updates_recurse (GdkWindow *window,
       gdk_region_destroy (child_region);
     }
 
+  g_list_foreach (children, g_object_unref, NULL);
+  g_list_free (children);
+
   if (!gdk_region_empty (expose_region))
     {
       if (private->event_mask & GDK_EXPOSURE_MASK)