gtk1.2 -> gtk2.0: recursing expose events

[Richard Guenther <rguenth tat physik uni-tuebingen de>]

Hi!

I'm trying to get GLAME ported to gtk/gnome 2.0 and am stuck at trying
to find out, why gtk segfaults on me if recursing into the expose event
of a GtkDrawingArea.

The matter is to do async redrawing by checking gtk_events_pending() in
a heavyweight redraw function which is connected to the expose_event of
a drawing area.

The code looks like

expose_event_cb()
{
   static int expose_cnt;

   if (expose_cnt++ > 0) {
       /* merge exposes */
       return TRUE;
   }

again:
   expose_cnt = 0;

   for (;;) {

       /* partial redraw */

      if (gtk_events_pending()) {
           while (gtk_events_pending())
               gtk_main_iteration();

           if (expose_cnt > 0) {
              /* remember undrawn */
              goto out;
           }
      }

   }

out:
   if (expose_cnt > 0)
       goto again;

   return TRUE;
}

And I'm getting backtraces like

#5  <signal handler called>
#6  0x0f057370 in gdk_event_get_graphics_expose () from
/usr/lib/libgdk-x11-2.0.so.0
#7  0x0f058f30 in gdk_add_client_message_filter () from
/usr/lib/libgdk-x11-2.0.so.0
#8  0x0f0591d0 in _gdk_events_queue () from /usr/lib/libgdk-x11-2.0.so.0
#9  0x0f059474 in _gdk_events_queue () from /usr/lib/libgdk-x11-2.0.so.0
#10 0x0ede7990 in g_get_current_time () from /usr/lib/libglib-2.0.so.0
#11 0x0ede8c78 in g_main_context_dispatch () from
/usr/lib/libglib-2.0.so.0
#12 0x0ede9000 in g_main_context_dispatch () from
/usr/lib/libglib-2.0.so.0
#13 0x0ede9264 in g_main_context_iteration () from
/usr/lib/libglib-2.0.so.0
#14 0x0f1a063c in gtk_main_iteration () from /usr/lib/libgtk-x11-2.0.so.0

where frame #14 is the gtk_main_iteration() call in the above loop.

Any hints what changed between gtk1.2 and 2.0 to make this fail? Any ideas
on how to convert such handlers?

Thanks,

Richard.

PS: please CC me, I'm not on this list.