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User-Agent: Opera/7.11 (Linux 2.4.20-9 i686; U)  [en]

Description of problem:
Stepping through this program with gdb causes a SIGSEGV. This program runs fine 
otherwise. Memory debuggers like Electric Fence and valgrind give it a clean 
bill of health, but under gdb it crashes. I will attach the program shortly.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Compile program without optimization: "g++ foo.cc -g -o foo"
2. Invoke gdb on foo and set breakpoint at line 46 (d->HandleEvent(d))
3. Step until SIGSEGV happens.

Actual Results:  Here is the transcript:

$ g++ foo.cc -g -o foo
$ gdb foo
GNU gdb Red Hat Linux (5.3post-0.20021129.18rh)
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-redhat-linux-gnu"...
(gdb) break foo.cc:46
Breakpoint 1 at 0x80488d0: file foo.cc, line 46.
(gdb) r
Starting program: /home/chris/foo

Breakpoint 1, main () at foo.cc:46
46         d->HandleEvent(d);
(gdb) s
XEventBroker::HandleEvent(XObjectEventListener*) (this=0x8049ee0,
    listener=0x8049ee4) at foo.cc:30
30         listener->ProcessEvent();
(gdb) s
XObjectEventListener::ProcessEvent() (this=0x8049ee4) at foo.cc:35
35         ProcessMessage();
(gdb) s

Program received signal SIGSEGV, Segmentation fault.
0x0804897a in non-virtual thunk to Derived::ProcessMessage() ()
    at streambuf:131
131           char_type                 _M_pback[_S_pback_size];
(gdb) bt
#0  0x0804897a in non-virtual thunk to Derived::ProcessMessage() ()
    at streambuf:131
#1  0x0804880a in XObjectEventListener::ProcessEvent() (this=0x8049ee0)
    at foo.cc:35
#2  0x080487ed in XEventBroker::HandleEvent(XObjectEventListener*) (
    this=0x8049ee0, listener=0x8049ee4) at foo.cc:30
#3  0x08048900 in main () at foo.cc:46
#4  0x420156a4 in __libc_start_main () from /lib/tls/libc.so.6
    

Expected Results:  The program should have run to completion without error.

Additional info: