Version:           4.00.80 (KDE 4.0.80 >= 20080104) (using 4.00.80 (KDE 4.0.80 >= 20080104), Gentoo)
Compiler:          i686-pc-linux-gnu-gcc
OS:                Linux (i686) release 2.6.23-gentoo-r3

Today I tried to reproduce bug #156623 by crashing konqueror while the GDB was running. However, the first time I tried it, gdb created the backtrace that I'll attach to this bug. (In all subsequent runs GDB produced the "correct" backtrace...)

Starting program: /usr/kde/svn/bin/konqueror 
[Thread debugging using libthread_db enabled]
[New Thread 0xb63f3a10 (LWP 6265)]
[New Thread 0xb2e9db90 (LWP 6274)]
[New Thread 0xb269cb90 (LWP 6275)]
[New Thread 0xb1e9bb90 (LWP 6276)]
[Thread 0xb1e9bb90 (LWP 6276) exited]
[Thread 0xb2e9db90 (LWP 6274) exited]
[Thread 0xb269cb90 (LWP 6275) exited]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb63f3a10 (LWP 6265)]
mem2mem_check (ptr=0x82687f0, sz=22) at hooks.c:135
135	hooks.c: No such file or directory.
	in hooks.c
Current language:  auto; currently c
#0  mem2mem_check (ptr=0x82687f0, sz=22) at hooks.c:135
#1  0xb6655435 in *__GI___libc_malloc (bytes=22) at malloc.c:3544
#2  0xb722109d in qMalloc (size=22) at global/qglobal.cpp:1964
#3  0xb726873e in QString (this=0xbfa401cc, ch={ucs = 32}) at tools/qstring.cpp:837
#4  0xb726ec3a in QString::operator= (this=0xbfa40530, ch={ucs = 32}) at tools/qstring.cpp:1137
#5  0xb7260435 in QRegExpEngine::Box::set (this=0xbfa4050c, ch={ucs = 32}) at tools/qregexp.cpp:2430
#6  0xb726058d in QRegExpEngine::parseAtom (this=0x824e670, box=0xbfa4050c) at tools/qregexp.cpp:3117
#7  0xb72609ff in QRegExpEngine::parseFactor (this=0x824e670, box=0xbfa4050c) at tools/qregexp.cpp:3205
#8  0xb7260e9d in QRegExpEngine::parseTerm (this=0x824e670, box=0xbfa4050c) at tools/qregexp.cpp:3267
#9  0xb7260f46 in QRegExpEngine::parseExpression (this=0x824e670, box=0xbfa4050c) at tools/qregexp.cpp:3278
#10 0xb726109e in QRegExpEngine::parse (this=0x824e670, pattern=0x82ae932, len=8) at tools/qregexp.cpp:3023
#11 0xb726189f in QRegExpEngine (this=0x824e670, key=@0x82ae3a4) at tools/qregexp.cpp:1323
#12 0xb7261c8a in prepareEngine_helper (priv=0x82ae3a0) at tools/qregexp.cpp:3364
#13 0xb7261e23 in QRegExp::operator= (this=0xbfa44854, rx=@0xb4c252e4) at tools/qregexp.cpp:3375
#14 0xb726205c in QRegExp (this=0xbfa44854, rx=@0xb4c252e4) at tools/qregexp.cpp:3470
#15 0xb726e41f in QString::replace (this=0x8281cbc, rx=@0xb4c252e4, after=@0xbfa448b4) at tools/qstring.cpp:2276
#16 0xb49f06c6 in FontFamilyValueImpl (this=0x8281ca0, string=@0xbfa4493c)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/css_valueimpl.cpp:1259
#17 0xb49f9a81 in DOM::CSSParser::parseFontFamily (this=0xbfa45e78)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/cssparser.cpp:1918
#18 0xb49fcf12 in DOM::CSSParser::parseValue (this=0xbfa45e78, propId=40, important=false)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/cssparser.cpp:860
#19 0xb4a16d81 in cssyyparse (parser=0xbfa45e78)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/parser.cpp:2712
#20 0xb49fdd93 in DOM::CSSParser::runParser (this=0xbfa45e78, length=894)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/cssparser.cpp:160
#21 0xb49fe204 in DOM::CSSParser::parseSheet (this=0xbfa45e78, sheet=0x8280b20, string=@0x827fb0c)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/cssparser.cpp:175
#22 0xb49e595b in DOM::CSSStyleSheetImpl::parseString (this=0x8280b20, string=@0x827fb0c, strict=false)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/css/css_stylesheetimpl.cpp:280
#23 0xb491c05a in DOM::HTMLLinkElementImpl::setStyleSheet (this=0x82ffec8, url=@0x827fad8, sheetStr=@0x827fb0c, 
    charset=@0xbfa45f58) at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/html/html_headimpl.cpp:244
#24 0xb4a1f050 in khtml::CachedCSSStyleSheet::checkNotify (this=0x827fad0)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/misc/loader.cpp:288
#25 0xb4a23eb7 in khtml::CachedCSSStyleSheet::data (this=0x827fad0, buffer=@0x8420684, eof=true)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/misc/loader.cpp:278
#26 0xb4a20d89 in khtml::Loader::slotFinished (this=0x8233dd0, job=0x82ac088)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/khtml/misc/loader.cpp:1299
#27 0xb4a21071 in khtml::Loader::qt_metacall (this=0x8233dd0, _c=QMetaObject::InvokeMetaMethod, _id=3, _a=0xbfa4656c)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/khtml/loader.moc:126
#28 0xb73071f4 in QMetaObject::activate (sender=0x82ac088, from_signal_index=7, to_signal_index=7, 
    argv=<value optimized out>) at kernel/qobject.cpp:3081
#29 0xb7307d94 in QMetaObject::activate (sender=0x82ac088, m=0xb7c073a8, local_signal_index=3, argv=0xbfa4656c)
    at kernel/qobject.cpp:3140
#30 0xb7b05e34 in KJob::result (this=0x82ac088, _t1=0x82ac088)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/kdecore/kjob.moc:185
#31 0xb7b06372 in KJob::emitResult (this=0x82ac088)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kdecore/jobs/kjob.cpp:290
#32 0xb7cbe568 in KIO::SimpleJob::slotFinished (this=0x82ac088)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kio/kio/job.cpp:491
#33 0xb7cbe91a in KIO::TransferJob::slotFinished (this=0x82ac088)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kio/kio/job.cpp:961
#34 0xb7cc54b3 in KIO::TransferJob::qt_metacall (this=0x82ac088, _c=QMetaObject::InvokeMetaMethod, _id=47, _a=0xbfa46bf4)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/kio/jobclasses.moc:335
#35 0xb73071f4 in QMetaObject::activate (sender=0x83d6660, from_signal_index=8, to_signal_index=8, 
    argv=<value optimized out>) at kernel/qobject.cpp:3081
#36 0xb7307d94 in QMetaObject::activate (sender=0x83d6660, m=0xb7e2f024, local_signal_index=4, argv=0x0)
    at kernel/qobject.cpp:3140
#37 0xb7d66746 in KIO::SlaveInterface::finished (this=0x83d6660)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/kio/slaveinterface.moc:160
#38 0xb7d6830a in KIO::SlaveInterface::dispatch (this=0x83d6660, _cmd=104, rawdata=@0xbfa46dd4)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kio/kio/slaveinterface.cpp:176
#39 0xb7d68f66 in KIO::SlaveInterface::dispatch (this=0x83d6660)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kio/kio/slaveinterface.cpp:90
#40 0xb7d5b637 in KIO::Slave::gotInput (this=0x83d6660)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kio/kio/slave.cpp:318
#41 0xb7d5cb8d in KIO::Slave::qt_metacall (this=0x83d6660, _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfa472f4)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/kio/slave.moc:74
#42 0xb73071f4 in QMetaObject::activate (sender=0x8298d18, from_signal_index=4, to_signal_index=4, 
    argv=<value optimized out>) at kernel/qobject.cpp:3081
#43 0xb7307d94 in QMetaObject::activate (sender=0x8298d18, m=0xb7e2bf20, local_signal_index=0, argv=0x0)
    at kernel/qobject.cpp:3140
#44 0xb7c96953 in KIO::Connection::readyRead (this=0x8298d18)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/kio/connection.moc:83
#45 0xb7c977d6 in KIO::ConnectionPrivate::dequeue (this=0x82c1150)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kio/kio/connection.cpp:82
#46 0xb7c98585 in KIO::Connection::qt_metacall (this=0x8298d18, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0x81e4f98)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs_build/kio/connection.moc:71
#47 0xb73022f9 in QMetaCallEvent::placeMetaCall (this=0x824aca8, object=0x8298d18) at kernel/qobject.cpp:536
#48 0xb7305017 in QObject::event (this=0x8298d18, e=0xff6fff49) at kernel/qobject.cpp:1122
#49 0xb6994e8a in QApplicationPrivate::notify_helper (this=0x80587d0, receiver=0x8298d18, e=0x824aca8)
    at kernel/qapplication.cpp:3556
#50 0xb699677a in QApplication::notify (this=0xbfa47c38, receiver=0x8298d18, e=0x824aca8) at kernel/qapplication.cpp:3115
#51 0xb78d2083 in KApplication::notify (this=0xbfa47c38, receiver=0x8298d18, event=0x824aca8)
    at /var/tmp/portage/kde-base/kdelibs-9999.4/work/kdelibs-9999.4/kdeui/kernel/kapplication.cpp:314
#52 0xb72f3d7b in QCoreApplication::notifyInternal (this=0xbfa47c38, receiver=0x8298d18, event=0x824aca8)
    at kernel/qcoreapplication.cpp:530
#53 0xb72f521a in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x804ce50)
    at kernel/qcoreapplication.h:200
#54 0xb72f556d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1001
#55 0xb6a1eaee in QEventDispatcherX11::processEvents (this=0x8057f50, flags=@0xbfa479f4)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:205
#56 0xb72f3191 in QEventLoop::processEvents (this=0xbfa47a60, flags=@0xbfa47a28) at kernel/qeventloop.cpp:140
#57 0xb72f329a in QEventLoop::exec (this=0xbfa47a60, flags=@0xbfa47a68) at kernel/qeventloop.cpp:186
#58 0xb72f5626 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:759
#59 0xb6994487 in QApplication::exec () at kernel/qapplication.cpp:3053
#60 0xb7f663bf in kdemain (argc=1, argv=0xbfa47f34)
    at /var/tmp/portage/kde-base/kdebase-9999.4/work/kdebase-9999.4/apps/konqueror/src/konqmain.cpp:218
#61 0x080487e2 in main (argc=Cannot access memory at address 0xff6fff49
) at /var/tmp/portage/kde-base/kdebase-9999.4/work/kdebase_build/apps/konqueror/src/konqueror_dummy.cpp:3
#62 0xb6601fdc in __libc_start_main (main=0x80487c0 <main>, argc=1, ubp_av=0xbfa47f34, init=0x8048810 <__libc_csu_init>, 
    fini=0x8048800 <__libc_csu_fini>, rtld_fini=0xb7f89100 <_dl_fini>, stack_end=0xbfa47f2c) at libc-start.c:229
#63 0x08048731 in _start ()
The program is running.  Exit anyway? (y or n)