Can you describe data, which you insert in QListWidgetItem as QVariant?

A graphicsitem that inherits from QObject and QGraphicsPixmapItem.

you must register your data:

are you insert graphicsitem as pointer?

Yes, as pointer. I cast QObject* when i set data.

I think i solved the problem. First, i look pointer classes like QPointer, QSharedDataPointer etc for stream operators that needed by qRegisterMetaTypeStreamOperators. I haven’t found any. Then i set data as qint32. It works fine but storing pointers with qint32 type seems little weird.

Btw, item that has data with unregistered type and QAstractItemView::defaultDropAction set to IgnoreAction or CopyAction or LinkAction causes segmentation fault. Is this a desired behaviour?

If you just copy around pointers it might be that the original object has been deleted already and you work on a dangling pointer then.

A segmentation fault is never a desired behavior :-)

I think it is not desired too. Object is not deleted btw. I’ll report this issue.

Are you sure, it is not deleted? Did you consider using a debugger to look where the segfault pops up? You’ll get a nice stack trace that leads you to the misbehaving line of code.

Yes i am sure object is not deleted. Object’s pointer is not important. QListWidget doesn’t try to access my custom object. It just stores my object’s memory address. I made data type to qint64 btw. qint32 is not enough.

You should use a debugger to see where the segfault happens (access to which object in which place, etc.) We can’t help any further on that. It’s unlikely to be a bug in the Qt libs as thousands of programmers use this code without any problems.

bug report [bugreports.qt.nokia.com]

I added sample code at comment. You can try quickly.

Nobody can produce an executable from this snippet.

You should create a minimal, complete project to demonstrate the problem.

And could you please tell us if you used a debugger to look where and on which object the segfault happened?

I used debugger and didn’t get any useful information. My project that produces this bug: project [rapidshare.com]