Application: cantor (0.2)
KDE Platform Version: 4.7.4 (4.7.4)
Qt Version: 4.7.4
Operating System: Linux 3.0.0-17-generic x86_64
Distribution: Ubuntu 11.10

-- Information about the crash:
I am trying to open a Cantor worksheet on the Octave backend, but opening it invariably results in a segfault. The problem occured after I run this code in the file:

plot(x, a+b*x)
hold on
plot(x, y, '+','color','red')
ylabel('O')
xlabel('W^6')
legend('Sovite a+bW^6','Mittauspisteet')
title('Purkautumiskayran sovite, a = 0.002891, b = 0.09619')
print -dpng foo.png

Once that ran, Cantor segfaulted and it keeps on doing so if I attempt to open the file.

The crash can be reproduced every time.

-- Backtrace:
Application: Cantor (cantor), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f8725ede780 (LWP 4109))]

Thread 3 (Thread 0x7f8712586700 (LWP 4110)):
#0  0x00007f8722cc9473 in poll () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007f871f93cf68 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f871f93d429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f8723431f3e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007f8723405cf2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#5  0x00007f8723405ef7 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#6  0x00007f872331d27f in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007f87233e8cbf in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#8  0x00007f872331fd05 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#9  0x00007f871fe0eefc in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#10 0x00007f8722cd559d in clone () from /lib/x86_64-linux-gnu/libc.so.6
#11 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f8706f22700 (LWP 4113)):
#0  0x00007fff62fff92c in clock_gettime ()
#1  0x00007f871dd5307b in clock_gettime () from /lib/x86_64-linux-gnu/librt.so.1
#2  0x00007f8723370074 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#3  0x00007f87234326ed in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007f8723432a33 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#5  0x00007f872343144c in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#6  0x00007f87234314f5 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007f871f93bff2 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#8  0x00007f871f93cdfd in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#9  0x00007f871f93d429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007f8723431f3e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#11 0x00007f8723405cf2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#12 0x00007f8723405ef7 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#13 0x00007f872331d27f in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#14 0x00007f87233e8cbf in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#15 0x00007f872331fd05 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#16 0x00007f871fe0eefc in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#17 0x00007f8722cd559d in clone () from /lib/x86_64-linux-gnu/libc.so.6
#18 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f8725ede780 (LWP 4109)):
[KCrash Handler]
#6  0x00007f87233a4173 in QIODevice::write(char const*, long long) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007f87159198ed in write (data=..., this=<optimized out>) at /usr/include/qt4/QtCore/qiodevice.h:127
#8  OctaveSession::runExpression (this=0x280fd90, expression=0x2f084b0) at ../../../../src/backends/octave/octavesession.cpp:153
#9  0x00007f871591b32e in OctaveExpression::evaluate (this=0x2f084b0) at ../../../../src/backends/octave/octaveexpression.cpp:96
#10 0x00007f871591889b in OctaveSession::evaluateExpression (this=0x280fd90, command=..., finishingBehavior=Cantor::Expression::DoNotDelete) at ../../../../src/backends/octave/octavesession.cpp:136
#11 0x00007f871591d249 in OctaveHighlighter::updateFunctions (this=0x2f21f20) at ../../../../src/backends/octave/octavehighlighter.cpp:57
#12 0x00007f871591d3bf in OctaveHighlighter::OctaveHighlighter (this=0x2f21f20, parent=<optimized out>, session=<optimized out>) at ../../../../src/backends/octave/octavehighlighter.cpp:28
#13 0x00007f8715918a94 in OctaveSession::syntaxHighlighter (this=0x280fd90, parent=0x2a66600) at ../../../../src/backends/octave/octavesession.cpp:277
#14 0x00007f8711b6c344 in Worksheet::enableHighlighting (this=0x2a66600, highlight=<optimized out>) at ../../src/worksheet.cpp:531
#15 0x00007f8711b6ce09 in Worksheet::load (this=0x2a66600, filename=<optimized out>) at ../../src/worksheet.cpp:755
#16 0x00007f8711b652c6 in CantorPart::openFile (this=0x294a340) at ../../src/cantor_part.cpp:264
#17 0x00007f872547185c in ?? () from /usr/lib/libkparts.so.4
#18 0x00007f8725471ea4 in KParts::ReadOnlyPart::openUrl(KUrl const&) () from /usr/lib/libkparts.so.4
#19 0x000000000040b661 in CantorShell::load (this=0x24edaa0, url=...) at ../../src/cantor.cpp:101
#20 0x000000000040bc1a in CantorShell::fileOpen (this=0x24edaa0) at ../../src/cantor.cpp:207
#21 0x000000000040da24 in CantorShell::qt_metacall (this=0x24edaa0, _c=QMetaObject::InvokeMetaMethod, _id=<optimized out>, _a=0x7fff62f27db0) at ./cantor.moc:96
#22 0x00007f8723419eba in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#23 0x00007f8723e00bb2 in QAction::triggered(bool) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#24 0x00007f8723e00d9f in QAction::activate(QAction::ActionEvent) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#25 0x00007f87241bf4fa in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#26 0x00007f87241bf7ac in QAbstractButton::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#27 0x00007f872427c39a in QToolButton::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#28 0x00007f8723e57cea in QWidget::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#29 0x00007f8723e07474 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#30 0x00007f8723e0ccbb in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#31 0x00007f87258cf466 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#32 0x00007f8723406afc in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#33 0x00007f8723e08442 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#34 0x00007f8723e879d5 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#35 0x00007f8723e8694e in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#36 0x00007f8723eaf4a2 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#37 0x00007f871f93ca5d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#38 0x00007f871f93d258 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#39 0x00007f871f93d429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#40 0x00007f8723431ed6 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#41 0x00007f8723eaf10e in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#42 0x00007f8723405cf2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#43 0x00007f8723405ef7 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#44 0x00007f872340a789 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#45 0x000000000040a227 in main (argc=5, argv=0x7fff62f294c8) at ../../src/main.cpp:87

Reported using DrKonqi