Bug 704 – Program crashe sometimes when the class multiple inherits from an old style class

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Bug 704 - Program crashe sometimes when the class multiple inherits from an old style class

Summary:

Program crashe sometimes when the class multiple inherits from an old style c...

Status:	CLOSED FIXED

Product:	PySide
Classification:	Unclassified
Component:	PySide
Version:	1.0.0 rc1
Platform:	All All

Importance:	P2 normal
Assigned To:	renato filho

URL:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2011-02-28 22:49 EET by flyaflya
Modified:	2011-04-01 23:15 EEST (History)
CC List:	8 users (show)

See Also:

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Description flyaflya 2011-02-28 22:49:43 EET

My project has many class using multiple inheritance to reuse some code, like
thses:

Class FooDialog(QDialog, MixinBase):
          .....

I find when the MixinBase defined as an old style class, the program often
crash.

Class MixinBase:
     pass

But when make it a new style class, the problem goes awary.

Class MixinBase(object):
    pass

Because it is only occasional, I can't write some code to display it, just post
the issue here.

Comment 1 Hugo Parente Lima 2011-03-01 11:21:50 EET

Thanks for reporting.

Comment 2 renato filho 2011-03-16 22:07:58 EET

After some discussion we decided does not allow use old style classes in
multiple inheritance with PySide classes, because this can cause a
unpredictable behavior on shiboken code.

Because of that PySide will raise a error when using a old style class for
multiple inheritance.

fixed on shiboken commit:

commit a72c6be47d0be58a1c3ab174397b79662400e181
Author: Renato Filho <renato.filho@openbossa.org>
Date:   Mon Mar 14 18:17:03 2011 -0300

Comment 3 Matti Airas 2011-03-18 11:14:11 EET

The decision sounds sensible, but have you documented this on the wiki or the
ref docs? I think it'd be essential to describe these kinds of design decisions
there.

Comment 4 Hugo Parente Lima 2011-03-18 16:42:29 EET

(In reply to comment #3)
> The decision sounds sensible, but have you documented this on the wiki or the
> ref docs? I think it'd be essential to describe these kinds of design decisions
> there.

Now an exception with a useful description is throw when you inherit from an
old style class.

Comment 5 renato filho 2011-03-18 19:28:46 EET

documentation added on shiboken, in commit:

commit 9c82464874bef7535690d245f84b70932109087b
Author: Renato Filho <renato.filho@openbossa.org>
Date:   Fri Mar 18 11:16:50 2011 -0300

Comment 6 Hugo Parente Lima 2011-04-01 23:15:59 EEST

Closing bug after release of PySide 1.0.1.