Application: cantor (0.1)
KDE Platform Version: 4.4.1 (KDE 4.4.1)
Qt Version: 4.6.2
Operating System: Linux 2.6.33-rc6 x86_64
Distribution (Platform): Gentoo Packages

-- Information about the crash:
I tried solving some random system of equations, then clicked to interrupt the calculation after a while, resulting in the backend crashing.

I then tried re-solving 1+1; (as can be seen in the backtrace), and cantor crashed.

(In kde 4.3.5, it used to ask for a bug report title, before searching for duplicates instead of after, in 4.4.1 it now searched before, and found nothing.)

 -- Backtrace:
Application: Cantor (cantor), signal: Segmentation fault
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib/libgobject-2.0.so.0.2200.4-gdb.py", line 9, in <module>
    from gobject import register
  File "/usr/share/glib-2.0/gdb/gobject.py", line 3, in <module>
    import gdb.backtrace
ImportError: No module named backtrace
The current source language is "auto; currently c".
[KCrash Handler]
#5  QIODevice::d_func (this=0x0, data=0x13f77f8 "1+1;\n", maxSize=5) at ../../include/QtCore/../../src/corelib/io/qiodevice.h:168
#6  QIODevice::write (this=0x0, data=0x13f77f8 "1+1;\n", maxSize=5) at io/qiodevice.cpp:1264
#7  0x00007f617e05b69a in QIODevice::write (this=0xa952c0) at /usr/include/qt4/QtCore/qiodevice.h:127
#8  MaximaSession::runFirstExpression (this=0xa952c0) at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/backends/maxima/maximasession.cpp:421
#9  0x00007f617e05b922 in MaximaSession::appendExpressionToQueue (this=0xa952c0, expr=0x8e1000)
    at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/backends/maxima/maximasession.cpp:239
#10 0x00007f617e05f15e in MaximaExpression::evaluate (this=0x8e1000) at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/backends/maxima/maximaexpression.cpp:119
#11 0x00007f617e05a04e in MaximaSession::evaluateExpression (this=0xa952c0, cmd=..., behave=Cantor::Expression::DoNotDelete)
    at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/backends/maxima/maximasession.cpp:214
#12 0x00007f61798093aa in Worksheet::evaluateEntry (this=0xa8c8e0, entry=0x735390) at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/worksheet.cpp:378
#13 0x00007f6179809613 in Worksheet::evaluateCurrentEntry (this=0xa8c8e0) at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/worksheet.cpp:361
#14 0x00007f617980be21 in Worksheet::qt_metacall (this=0xa8c8e0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffffffa460)
    at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1_build/cantor/src/worksheet.moc:127
#15 0x00007f618e8a5167 in QMetaObject::activate (sender=0x68d160, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x13f77fc) at kernel/qobject.cpp:3285
#16 0x00007f618f2d5d52 in QAction::triggered (this=0x0, _t1=false) at .moc/release-shared/moc_qaction.cpp:263
#17 0x00007f618f2d7d90 in QAction::activate (this=0x68d160, event=<value optimized out>) at kernel/qaction.cpp:1255
#18 0x00007f618f2d965f in QAction::event (this=0x0, e=<value optimized out>) at kernel/qaction.cpp:1181
#19 0x00007f6191621e83 in KAction::event (this=0x0, event=0x7fffffffab60) at /var/tmp/portage/kde-base/kdelibs-4.4.1-r1/work/kdelibs-4.4.1/kdeui/actions/kaction.cpp:129
#20 0x00007f618f2dbf2d in QApplicationPrivate::notify_helper (this=0x62ecf0, receiver=0x68d160, e=0x7fffffffab60) at kernel/qapplication.cpp:4300
#21 0x00007f618f2e3304 in QApplication::notify (this=0x7fffffffc1a0, receiver=0x68d160, e=0x7fffffffab60) at kernel/qapplication.cpp:3704
#22 0x00007f61916f822b in KApplication::notify (this=0x7fffffffc1a0, receiver=0x68d160, event=0x7fffffffab60)
    at /var/tmp/portage/kde-base/kdelibs-4.4.1-r1/work/kdelibs-4.4.1/kdeui/kernel/kapplication.cpp:302
#23 0x00007f618e891dab in QCoreApplication::notifyInternal (this=0x7fffffffc1a0, receiver=0x68d160, event=0x7fffffffab60) at kernel/qcoreapplication.cpp:704
#24 0x00007f618f318278 in QCoreApplication::sendEvent (this=<value optimized out>, e=0x7fffffffb1d0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#25 QShortcutMap::dispatchEvent (this=<value optimized out>, e=0x7fffffffb1d0) at kernel/qshortcutmap.cpp:879
#26 0x00007f618f319f0c in QShortcutMap::tryShortcutEvent (this=0x62ee18, o=<value optimized out>, e=0x7fffffffb1d0) at kernel/qshortcutmap.cpp:364
#27 0x00007f618f2e4dbc in QApplication::notify (this=0x7fffffffc1a0, receiver=0xa8c8e0, e=0x7fffffffb1d0) at kernel/qapplication.cpp:3746
#28 0x00007f61916f822b in KApplication::notify (this=0x7fffffffc1a0, receiver=0xa8c8e0, event=0x7fffffffb1d0)
    at /var/tmp/portage/kde-base/kdelibs-4.4.1-r1/work/kdelibs-4.4.1/kdeui/kernel/kapplication.cpp:302
#29 0x00007f618e891dab in QCoreApplication::notifyInternal (this=0x7fffffffc1a0, receiver=0xa8c8e0, event=0x7fffffffb1d0) at kernel/qcoreapplication.cpp:704
#30 0x00007f618f3872a4 in QKeyMapper::sendKeyEvent (keyWidget=0xa8c8e0, grab=<value optimized out>, type=QEvent::KeyPress, code=16777220, modifiers=..., text=..., autorepeat=false, count=1, 
    nativeScanCode=36, nativeVirtualKey=65293, nativeModifiers=1) at kernel/qkeymapper_x11.cpp:1861
#31 0x00007f618f389559 in QKeyMapperPrivate::translateKeyEvent (this=0x6691f0, keyWidget=0xa8c8e0, event=0x7fffffffbde0, grab=248) at kernel/qkeymapper_x11.cpp:1831
#32 0x00007f618f3634cd in QApplication::x11ProcessEvent (this=0x7fffffffc1a0, event=0x7fffffffbde0) at kernel/qapplication_x11.cpp:3394
#33 0x00007f618f38c75a in x11EventSourceDispatch (s=0x632ab0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#34 0x00007f618a55ad59 in g_main_dispatch (context=0x631920) at gmain.c:1960
#35 IA__g_main_context_dispatch (context=0x631920) at gmain.c:2513
#36 0x00007f618a55e5a8 in g_main_context_iterate (context=0x631920, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2591
#37 0x00007f618a55e75c in IA__g_main_context_iteration (context=0x631920, may_block=1) at gmain.c:2654
#38 0x00007f618e8bb54c in QEventDispatcherGlib::processEvents (this=0x618270, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:412
#39 0x00007f618f38c2ff in QGuiEventDispatcherGlib::processEvents (this=0x0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#40 0x00007f618e8906d2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#41 0x00007f618e890aa4 in QEventLoop::exec (this=0x7fffffffc110, flags=...) at kernel/qeventloop.cpp:201
#42 0x00007f618e892ef6 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#43 0x000000000040ac7c in main (argc=1, argv=0x7fffffffc4a8) at /var/tmp/portage/kde-base/cantor-4.4.1/work/cantor-4.4.1/cantor/src/main.cpp:85

Reported using DrKonqi