[Qt-interest] QtScript segfault on C++ signal (dis)connection/firing

[Sean M. Pappalardo]

Hello there.

I'm developing a fairly large QtScript file (35K at the moment) which
necessarily involves many C++ object signals being connected and
disconnected at various points depending on user action.

The problem is the application will randomly cause a segmentation fault
when a signal fires (it could be any of them.) It seems to have gotten
worse the more signals I add to the script.

The signals are (dis)connected via a Q_INVOKABLE C++ function that calls
qScriptConnect and qScriptDisconnect. This way, scripts need only one
line of code to connect/disconnect a signal.

This may be related to another strange problem I found where I have to
connect all signals once at the beginning of the script or they won't
have any effect if connected for the first time later on. (I've found
one exception to this too.)

(I also originally tried to do this as shown in the QtScript docs by
exposing the object whose signals I wanted to connect, but the script
slot functions weren't being called once connected.)

If it's helpful, here's a link to a backtrace: http://pastebin.com/m5189a6f1

I also ran valgrind to check for leaks and it reported:

==21380== Process terminating with default action of signal 11 (SIGSEGV)
==21380==  Access not within mapped region at address 0x4
==21380==    at 0x529203A: (within /usr/lib/libQtScript.so.4.4.3)
==21380==    by 0x5292E1A: (within /usr/lib/libQtScript.so.4.4.3)
==21380==    by 0x432DD6A: QMetaCallEvent::placeMetaCall(QObject*) (in
/usr/lib/libQtCore.so.4.4.3)
==21380==    by 0x432F8E0: QObject::event(QEvent*) (in
/usr/lib/libQtCore.so.4.4.3)
==21380==    by 0x454079B: QApplicationPrivate::notify_helper(QObject*,
QEvent*) (in /usr/lib/libQtGui.so.4.4.3)
==21380==    by 0x454861D: QApplication::notify(QObject*, QEvent*) (in
/usr/lib/libQtGui.so.4.4.3)
==21380==    by 0x43200D0: QCoreApplication::notifyInternal(QObject*,
QEvent*) (in /usr/lib/libQtCore.so.4.4.3)
==21380==    by 0x4320D54:
QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)
(in /usr/lib/libQtCore.so.4.4.3)
==21380==    by 0x4320F4C: QCoreApplication::sendPostedEvents(QObject*,
int) (in /usr/lib/libQtCore.so.4.4.3)
==21380==    by 0x434A98E: (within /usr/lib/libQtCore.so.4.4.3)
==21380==    by 0x57001B7: g_main_context_dispatch (in
/usr/lib/libglib-2.0.so.0.1600.6)
==21380==    by 0x5703852: (within /usr/lib/libglib-2.0.so.0.1600.6)

Thank you very much for your time and attention. I would appreciate any
help or direction you can give.

Sincerely,
Sean M. Pappalardo

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