libgdl runtime error on gtk+-quartz

[John Swensen <jpswensen gmail com>]

I have compiled gtk+ using the script from Imendio and everything was  
working fine.  I have compiled several programs against it and they  
all work beautifully.  Then I decided to use the libgdl dock widget  
and ran into problems.

I am getting an error from dereferencing a bad pointer in  
g_type_check_instance_cast as called from  
gdk_window_impl_quartz_begin_paint_region.

Here is the top couple of entries from the backtrace:
0  0x02b5c9d0 in g_type_check_instance_cast (type_instance=0x1,  
iface_type=50472752) at gtype.c:3143
#1  0x01e9a512 in gdk_window_impl_quartz_begin_paint_region  
(paintable=0x17330, region=0x5c40) at gdkwindow-quartz.c:228
#2  0x01e8932f in gdk_window_begin_paint_region (window=0x2f530c8,  
region=0x5c40) at gdkwindow.c:991
#3  0x00ee35eb in gtk_main_do_event (event=0xbfffd544) at gtkmain.c:1513
#4  0x01e976e7 in -[GdkQuartzView drawRect:] (self=0x3086ce0,  
_cmd=0x95392630, rect={origin = {x = 0, y = 0}, size = {width = 375,  
height = 380}}) at GdkQuartzView.c:100

The thing that is most strange is that in the debugger, the paintable  
variable is non-NULL and looks like a valid memory location, but the  
variable impl = 0xfffffff1. This seems like an invalid memory  
address.  Even more strange, later on in  
gdk_window_impl_quartz_begin_paint(), the drawable_impl variable which  
is derived from impl also looks like a valid memory address.

I am not familiar enough with all of this code to know what the  
problem is, but if someone could direct me on where to look and what  
to try, I can do some of the footwork.

John Swensen

P.S. If you want more of the call stack, I can send all of it, but it  
is 28 calls deep.