Bug 841 – QStandardItem::clone and QStandardItemModel::setItemPrototype

PySide Bugzilla Closed for New Bugs

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Bug 841 - QStandardItem::clone and QStandardItemModel::setItemPrototype

Summary:

QStandardItem::clone and QStandardItemModel::setItemPrototype

Status:	CLOSED FIXED

Product:	PySide
Classification:	Unclassified
Component:	QtGui
Version:	HEAD
Platform:	PC MS Windows XP/Vista/7

Importance:	P2 normal
Assigned To:	renato filho

URL:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2011-04-27 19:49 EEST by Martin Preisler
Modified:	2011-05-26 17:03 EEST (History)
CC List:	9 users (show)

See Also:

Attachments
Failing application (1.90 KB, text/plain) 2011-04-28 18:45 EEST, Martin Preisler	Details
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Description Martin Preisler 2011-04-27 19:49:21 EEST

Hi!

I have implemented a simple drag and drop project management gui and python
keeps crashing whenever standard item model clones an item via the prototype
(if I don't set the prototype from python everything works).

I have worked extensively with py++ and boost::python but have only glanced at
shiboken so I might be wrong but I think the cloned instances are being
instantly garbage collected because nothing is taking ownership of them (and
upon returning them their ref count is 0).

The code in question:
http://crayzedsgui.hg.sourceforge.net/hgweb/crayzedsgui/CEED/file/6efa28938b3d/project.py#l92

The work around listed there works flawlessly but obviously isn't good in the
long run. It basically creates memory leaks.

I am using PySide nightly builds with Python 2.7 on Windows 7.

Comment 1 Hugo Parente Lima 2011-04-28 16:47:17 EEST

Thanks for reporting, but if it's not too much could you provide a small code
example showing only this issue? Will ease our job :-)

Comment 2 Martin Preisler 2011-04-28 18:45:37 EEST

Created attachment 319 [details]
Failing application

Contains a lot of boilerplate code but is standalone, just python and pyside
should suffice.

If you uncomment the workaround code it will work, comment it again and it will
segfault.

Comment 3 Martin Preisler 2011-04-28 18:47:01 EEST

(In reply to comment #2)
> Created attachment 319 [details]
> Failing application
> 
> Contains a lot of boilerplate code but is standalone, just python and pyside
> should suffice.
> 
> If you uncomment the workaround code it will work, comment it again and it will
> segfault.

oh stupid me... the segfault is triggered by drag moving any of the items in
the model. It happens upon dropping the item.

Comment 4 renato filho 2011-05-03 21:06:05 EEST

fixed on pyside commit:

commit 13d505c9c0a08381113154fd0880b6ac64e7ebf3
Author: Renato Filho <renato.filho@openbossa.org>
Date:   Tue May 3 12:21:10 2011 -0300

Comment 5 renato filho 2011-05-26 17:03:54 EEST

PySide release 1.0.3