(gdb) bt f
#0  0x0808c823 in privateExists (privates=0x151, key=0xb77d3234)
    at ../../dix/privates.c:79
No locals.
#1  dixLookupPrivate (privates=0x151, key=0xb77d3234)
    at ../../dix/privates.c:162
        ptr = <value optimized out>
#2  0xb77d1db9 in DRI2GetScreen (pScreen=<value optimized out>)
    at ../../../../hw/xfree86/dri2/dri2.c:78
No locals.
#3  0xb77d1edf in DRI2DestroyDrawable (pDraw=0x9280bd0)
    at ../../../../hw/xfree86/dri2/dri2.c:344
        ds = <value optimized out>
        pPriv = <value optimized out>
#4  0xb73f4228 in __glXDRIdrawableDestroy (drawable=0x92806f8)
    at ../../glx/glxdri2.c:110
No locals.
#5  0xb73e8bd8 in DrawableGone (glxPriv=0x92806f8, xid=58720288)
    at ../../glx/glxext.c:163
        c = 0x0
#6  0x0808fa4f in FreeClientResources (client=0x91e1518)
    at ../../dix/resource.c:806
        rtype = <value optimized out>
        resources = 0x9189210
        this = 0x932d228
        j = 32
#7  0x0806d1cf in CloseDownClient (client=0x91e1518)
    at ../../dix/dispatch.c:3631
        really_close_down = <value optimized out>
#8  0x08072e38 in Dispatch () at ../../dix/dispatch.c:450
        result = 1
        client = 0x91e1518
        nready = 0
        start_tick = 2340
#9  0x0806695a in main (argc=9, argv=0xbfa42904, envp=0xbfa4292c)
    at ../../dix/main.c:285
        i = <value optimized out>
        alwaysCheckForInput = {0, 1}
(gdb) select 3
(gdb) print pDraw->pScreen
$3 = (ScreenPtr) 0x1