[PyQt] Regression with guiqwt somewhere after PyQt4 4.10

[Dmitry Shachnev]

I should also have mentioned that I used a less complicated testcase
from http://bugs.debian.org/729392:

from guiqwt import pyplot
pyplot.plot([1, 2, 3])
pyplot.show()

--
Dmitry Shachnev

On Wed, Nov 13, 2013 at 3:54 PM, Dmitry Shachnev <mitya57 at ubuntu.com> wrote:
> The crash happens here (src/corelib/kernel/qmetaobject.cpp:525):
>
>     for (const QMetaObject *m = *baseObject; m; m = m->d.superdata) {
>         int i = (MethodType == MethodSignal && priv(m->d.data)->revision >= 4)
>                 ? (priv(m->d.data)->signalCount - 1) :
> (priv(m->d.data)->methodCount - 1);
>
> The problem is that m->d.data is null on the fourth iteration:
>
> (gdb) p **baseObject
> $12 = {d = {superdata = 0x8527d80, stringdata = 0x8712588
> "LevelsHistogram", data = 0x8fddb48, extradata = 0x0}}
> (gdb) p *(baseObject->d.superdata)
> $13 = {d = {superdata = 0x8ec6f00, stringdata = 0x88123b0 "CurvePlot",
> data = 0x8e156f8, extradata = 0x0}}
> (gdb) p *(baseObject->d.superdata->d.superdata)
> $14 = {d = {superdata = 0xb13244e0, stringdata = 0x8ecd1a0 "BasePlot",
> data = 0x8ef04e0, extradata = 0x0}}
> (gdb) p *(baseObject->d.superdata->d.superdata->d.superdata)
> $15 = {d = {superdata = 0xb12bc4ec, stringdata = 0x0, data = 0x0,
> extradata = 0xb12bc4cd}}
>
> A backtrace is attached.
>
> --
> Dmitry Shachnev
>
> On Sat, Nov 9, 2013 at 9:47 PM, Scott Kitterman <debian at kitterman.com> wrote:
>> Below is a part of an Ubuntu bug report.  You can find a reproduction test case
>> at https://bugs.launchpad.net/ubuntu/+source/python-qt4/+bug/1249571/+attachment/3903922/+files/test_guiqwt.py
>>
>> Scott K