Application: ktorrent (4.0.2)
KDE Platform Version: 4.4.5 (KDE 4.4.5)
Qt Version: 4.6.3
Operating System: Linux 2.6.32-5-686 i686
Distribution: Debian GNU/Linux unstable (sid)

-- Information about the crash:
Here we go again ;)

Last time, I restarted too fast & lost the backtrace, but now I have one.

The crash can be reproduced some of the time.

 -- Backtrace:
Application: KTorrent (ktorrent), signal: Segmentation fault
[Current thread is 1 (Thread 0xb4ac7710 (LWP 2581))]

Thread 6 (Thread 0xb34c3b70 (LWP 2630)):
#0  0xb7765424 in __kernel_vsyscall ()
#1  0xb5306f7f in __pthread_cond_wait (cond=0x97c1018, mutex=0x97c1000) at pthread_cond_wait.c:153
#2  0xb5b2d0bd in __pthread_cond_wait (cond=0x97c1018, mutex=0x97c1000) at forward.c:139
#3  0xb67e7562 in QMutexPrivate::wait (this=0x97c0fe8, timeout=-1) at thread/qmutex_unix.cpp:84
#4  0xb67e2ae2 in QMutex::lock (this=0x976b1b8) at thread/qmutex.cpp:205
#5  0xb7629113 in bt::Log::lock() () from /usr/lib/libktorrent.so.2
#6  0xb7629bb5 in bt::Out(unsigned int) () from /usr/lib/libktorrent.so.2
#7  0xb762a2ec in ?? () from /usr/lib/libktorrent.so.2
#8  0xb67def55 in qt_message_output (msgType=QtWarningMsg, buf=0xa5 <Address 0xa5 out of bounds>) at global/qglobal.cpp:2212
#9  0xb67df15a in qt_message (msgType=<value optimized out>, msg=0xb6994438 "QSocketNotifier: Invalid socket %d and type '%s', disabling...", ap=0xb34c3054 "\020") at global/qglobal.cpp:2312
#10 0xb67df339 in qWarning (msg=0xb6994438 "QSocketNotifier: Invalid socket %d and type '%s', disabling...") at global/qglobal.cpp:2394
#11 0xb691051c in socketNotifierSourceCheck (source=0x97e5560) at kernel/qeventdispatcher_glib.cpp:90
#12 0xb522c499 in g_main_context_check () from /lib/libglib-2.0.so.0
#13 0xb522cdce in ?? () from /lib/libglib-2.0.so.0
#14 0xb522d1b8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#15 0xb6910095 in QEventDispatcherGlib::processEvents (this=0x97e8c00, flags=...) at kernel/qeventdispatcher_glib.cpp:412
#16 0xb68e2b49 in QEventLoop::processEvents (this=0xb34c3290, flags=) at kernel/qeventloop.cpp:149
#17 0xb68e2f9a in QEventLoop::exec (this=0xb34c3290, flags=...) at kernel/qeventloop.cpp:201
#18 0xb67e5619 in QThread::exec (this=0x982ea08) at thread/qthread.cpp:487
#19 0xb76df03e in utp::UTPServerThread::run() () from /usr/lib/libktorrent.so.2
#20 0xb67e7fae in QThreadPrivate::start (arg=0x982ea08) at thread/qthread_unix.cpp:248
#21 0xb5302955 in start_thread (arg=0xb34c3b70) at pthread_create.c:300
#22 0xb5b2010e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 5 (Thread 0xb29b7b70 (LWP 2637)):
#0  0xb7765424 in __kernel_vsyscall ()
#1  0xb5b19291 in select () at ../sysdeps/unix/syscall-template.S:82
#2  0xb76a3105 in ?? () from /usr/lib/libktorrent.so.2
#3  0xb67e7fae in QThreadPrivate::start (arg=0x981f548) at thread/qthread_unix.cpp:248
#4  0xb5302955 in start_thread (arg=0xb29b7b70) at pthread_create.c:300
#5  0xb5b2010e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 4 (Thread 0xb0324b70 (LWP 2839)):
#0  0xb7765424 in __kernel_vsyscall ()
#1  0xb5307482 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:179
#2  0xb5b2d114 in __pthread_cond_timedwait (cond=0xb03241e8, mutex=0xb0324218, abstime=0xb0324260) at forward.c:152
#3  0xb67e78b1 in thread_sleep (ti=0x1) at thread/qthread_unix.cpp:398
#4  0xb67e79f3 in QThread::msleep (msecs=50) at thread/qthread_unix.cpp:424
#5  0xb763aa62 in ?? () from /usr/lib/libktorrent.so.2
#6  0xb763b3d8 in ?? () from /usr/lib/libktorrent.so.2
#7  0xb67e7fae in QThreadPrivate::start (arg=0x97628b0) at thread/qthread_unix.cpp:248
#8  0xb5302955 in start_thread (arg=0xb0324b70) at pthread_create.c:300
#9  0xb5b2010e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 3 (Thread 0xafb23b70 (LWP 2840)):
#0  0xb7765424 in __kernel_vsyscall ()
#1  0xb5307482 in pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_timedwait.S:179
#2  0xb5b2d114 in __pthread_cond_timedwait (cond=0xafb231e8, mutex=0xafb23218, abstime=0xafb23260) at forward.c:152
#3  0xb67e78b1 in thread_sleep (ti=0x1) at thread/qthread_unix.cpp:398
#4  0xb67e79f3 in QThread::msleep (msecs=50) at thread/qthread_unix.cpp:424
#5  0xb7639fb2 in ?? () from /usr/lib/libktorrent.so.2
#6  0xb763b3d8 in ?? () from /usr/lib/libktorrent.so.2
#7  0xb67e7fae in QThreadPrivate::start (arg=0x9762cb8) at thread/qthread_unix.cpp:248
#8  0xb5302955 in start_thread (arg=0xafb23b70) at pthread_create.c:300
#9  0xb5b2010e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 2 (Thread 0xaf322b70 (LWP 2841)):
#0  0xb7765424 in __kernel_vsyscall ()
#1  0xb5306f7f in __pthread_cond_wait (cond=0xad804570, mutex=0xad804558) at pthread_cond_wait.c:153
#2  0xb5b2d0bd in __pthread_cond_wait (cond=0xad804570, mutex=0xad804558) at forward.c:139
#3  0xb67e8fa7 in QWaitConditionPrivate::wait (this=0xa4bbdccc, mutex=0xa4bbdcc8, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  QWaitCondition::wait (this=0xa4bbdccc, mutex=0xa4bbdcc8, time=4294967295) at thread/qwaitcondition_unix.cpp:159
#5  0xb763e7da in ?? () from /usr/lib/libktorrent.so.2
#6  0xb67e7fae in QThreadPrivate::start (arg=0xa4bbdcc0) at thread/qthread_unix.cpp:248
#7  0xb5302955 in start_thread (arg=0xaf322b70) at pthread_create.c:300
#8  0xb5b2010e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

Thread 1 (Thread 0xb4ac7710 (LWP 2581)):
[KCrash Handler]
#6  _int_malloc (av=<value optimized out>, bytes=<value optimized out>) at malloc.c:4507
#7  0xb5ac3d2c in *__GI___libc_malloc (bytes=32768) at malloc.c:3661
#8  0xb67e25fd in qMalloc (size=32768) at global/qmalloc.cpp:55
#9  0xb67eb10b in QByteArray::realloc (this=0x977c07c, alloc=32748) at tools/qbytearray.cpp:1412
#10 0xb67eb625 in QByteArray::resize (this=0x977c07c, size=16384) at tools/qbytearray.cpp:1380
#11 0xb6871fb3 in QRingBuffer::reserve (this=0x97dad9c, bytes=67) at ../../include/QtCore/private/../../../src/corelib/tools/qringbuffer_p.h:158
#12 0xb687008e in QFile::writeData (this=0x97c8f88, data=0xae265b8 "Wed Jul 28 07:53:36 2010: Authentication to 72.190.18.53 : failure\n", len=67) at io/qfile.cpp:1646
#13 0xb687627e in QIODevice::write (this=0x97c8f88, data=0xae265b8 "Wed Jul 28 07:53:36 2010: Authentication to 72.190.18.53 : failure\n", maxSize=67) at io/qiodevice.cpp:1359
#14 0xb6886295 in QIODevice::write (this=0x97dafc0) at ../../include/QtCore/../../src/corelib/io/qiodevice.h:127
#15 QTextStreamPrivate::flushWriteBuffer (this=0x97dafc0) at io/qtextstream.cpp:679
#16 0xb68874f2 in flush (stream=...) at io/qtextstream.cpp:2878
#17 0xb688752c in operator<< (stream=...) at io/qtextstream.h:291
#18 endl (stream=...) at io/qtextstream.cpp:2866
#19 0xb762ae7e in ?? () from /usr/lib/libktorrent.so.2
#20 0xb762a112 in bt::endl(bt::Log&) () from /usr/lib/libktorrent.so.2
#21 0xb76454ac in ?? () from /usr/lib/libktorrent.so.2
#22 0xb7645981 in ?? () from /usr/lib/libktorrent.so.2
#23 0xb765a9c2 in bt::PeerConnector::start(bt::PeerConnector::Method) () from /usr/lib/libktorrent.so.2
#24 0xb765aa90 in bt::PeerConnector::start() () from /usr/lib/libktorrent.so.2
#25 0xb76517cb in bt::PeerManager::connectToPeers() () from /usr/lib/libktorrent.so.2
#26 0xb7684ba3 in bt::TorrentControl::update() () from /usr/lib/libktorrent.so.2
#27 0x0806b353 in _start ()

Reported using DrKonqi