when calling Release() on an IDirectFB object, it creates a signal 11 due to a double free. This occues on Kubuntu 10.10, amd64. This can be reproduced with the directfb tutorial application.
The call stack is
#0 __libc_free (mem=0x7ffff410e010) at malloc.c:3709
#1 0x00007ffff67f8012 in ?? () from /usr/lib/libX11.so.6
#2 0x00007ffff6b0a9fe in dfb_x11_close_window () from /usr/lib/directfb-1.2-9/systems/libdirectfb_x11.so
#3 0x00007ffff6b07584 in dfb_x11_destroy_window_handler () from /usr/lib/directfb-1.2-9/systems/libdirectfb_x11.so
#4 0x00007ffff6b08a00 in ?? () from /usr/lib/directfb-1.2-9/systems/libdirectfb_x11.so
#5 0x00007ffff71325a7 in fusion_call_execute () from /usr/lib/libfusion-1.2.so.9
#6 0x00007ffff6b06ed1 in ?? () from /usr/lib/directfb-1.2-9/systems/libdirectfb_x11.so
#7 0x00007ffff7bb473f in ?? () from /usr/lib/libdirectfb-1.2.so.9
#8 0x00007ffff7bb4f9a in dfb_layer_region_disable () from /usr/lib/libdirectfb-1.2.so.9
#9 0x00007ffff7bb5440 in ?? () from /usr/lib/libdirectfb-1.2.so.9
#10 0x00007ffff71348c2 in ?? () from /usr/lib/libfusion-1.2.so.9
#11 0x00007ffff713553c in fusion_ref_down () from /usr/lib/libfusion-1.2.so.9
#12 0x00007ffff7b6cb19 in IDirectFB_Destruct () from /usr/lib/libdirectfb-1.2.so.9
#13 0x00007ffff7b6cbba in ?? () from /usr/lib/libdirectfb-1.2.so.9
#14 0x0000000000402fbb in main (argc=1, argv=0x7fffffffe1d8) at main/linux/main.c:205
Attached sample source code.