Problem with Multicast classifier: Segmentation Fault

[Joerg Diederich <dieder@ibr.cs.tu-bs.de>]

Hi!

I played around a (very) little bit with multicast support in ns and
got the following problem in ns-2.1b5 and the current snapshot from
June, 16th (using also both tclcl-1.0b8 and tclcl-1.0b8-current from
June, 16th):

% set mc [new Classifier/Multicast]
_o4
% delete $mc
Segmentation fault

The problem does not appear in ns-2.1b4.

I could not really track down the problem, but the SegFault happens
somewhere in delete-shadow at different (changing) locations.

gdb output does not help, either:

Program received signal SIGSEGV, Segmentation fault.
0x4016c132 in __libc_free (mem=0x0)
Current language:  auto; currently c
(gdb) bt
#0  0x4016c132 in __libc_free (mem=0x0)
#1  0x8383c40 in ?? ()
#2  0x841 in ?? ()
Cannot access memory at address 0x2d70a.


I compiled ns with both gcc-2.7.2 and egcs-2.91.66, same results.

This is not really a problem for me as I am not using multicast that
much and as you can simply omit deleting objects, but it may be a hint
for other strange errors in that field...


With best regards,

/J"org
-----
J"org Diederich
Institute of Operating Systems and Computer Networks, 
Technical University Braunschweig, Germany
e-mail: dieder@ibr.cs.tu-bs.de