Multiple QRegExp crashes when multithreading in KRunner

[Matthias Fuchs]

Am Freitag 14 Januar 2011, 01:16:07 schrieb Thiago Macieira:
> On Thursday, 13 de January de 2011 15:08:06 Aaron J. Seigo wrote:
> > On Thursday, January 13, 2011, Thiago Macieira wrote:
> > > On Thursday, 13 de January de 2011 22:43:28 Matthias Fuchs wrote:
> > > > Hi,
> > > > 
> > > > There are some crashes related to QRegExp and multithreading, so
> > > > they
> > > > appear when using KRunner.
> > > 
> > > There should be no crashes related to QRegExp and threading since Qt
> > > 4.4.
> > > If you find something, it's usually because you used the same QRegExp
> > > object to conduct searches at the same time.
> > 
> > yes, that's exactly what's happening :) Matthias already fixed one
> > krunner plugin that was doing this, but not he's faced with the
> > Nepomuk::Query::QueryParser bits.
> > 
> > as it is internal to Nepomuk and it is using static members internal to
> > the library (meaning krunner or any other app can't just use a
> > "different Nepomuk object") QThreadStorage seems the easiest solution
> > here.
> 
> Nah.
> 
> Just create a copy on the stack:
> 
> QRegExp rx = theRx;
> if (rx.indexIn(str) != 0) { ... }

Yet that is what is happening in the KGet runner case [1] -- I simply create 
an instance of QRegExp on the stack -- and there it crashes too.

Now I understand that you mentioned to make a test case, though I can't 
reproduce this crash myself.
In the report Qt 4.6.3 is mentioned.

[1] 
http://websvn.kde.org/tags/KDE/4.4.5/kdenetwork/kget/plasma/runner/kgetrunner.cpp?revision=1142811&view=markup
Crash happens at line 114, also see 
https://bugs.kde.org/show_bug.cgi?id=255860