[bt-devel] close presenter bug

[Kevin Miller]

Sorry, correction I am running qt 2.3.0 from debian packages, if
that makes any difference.


On Thu, 7 Jun 2001, Kevin Miller wrote:

> I am running kde 2.1.2 from debian packages and qt 2.2.3 also
> from debian package.  I already did an --enable-debug build as
> that is how I was able to come up with the fix that I mentioned.
> The line that dies is the close call in any of the three
> presenters in the modulesChanged method.  The method checks to
> see if there is any remaining modules open for that window and if
> not calls close(), which is where the failure occurs--inside this
> method which must come from either one of the kde or qt ancestors
> of the class as I saw no such method defined in any of the
> presenter classes/subclasses.
>
> --- void CBiblePresenter::modulesChanged(){
> ---   m_moduleList = m_moduleChooserBar->getModuleList();
> ---   if (!m_moduleList.count())
> --->  	close();  //*** Dies in this call ****
> ---   else {
> ---     refreshFeatures();
> ---     m_key->module(m_moduleList.first());
> ---	m_keyChooser->setModule(m_moduleList.first());
> ---	lookup(m_key);
> ---   }
> --- }
>
> If I wasn't really clear on how to reproduce the bug, I apolgize.
> Here are my steps that will repeat the bug at any time in the cvs
> branch or in the beta1 build.
>
> 1.  Open Bibletime, then open a module in the presenter.  Doesn't
> matter if it is maximized or not.
>
> 2.  Click on the module chooser button in the open presenter's
> toolbar and choose 'None'.  The presenter window will close, then
> after a few seconds, Dr. Konqi comes up with seq fault
> information, or if he is turned off then it just seg faults.
>
> Hope this helps, please let me know if there is anything else I
> can do to help you out.
>
> Kevin
>
> On Thu, 7 Jun 2001 mg.pub@gmx.net wrote:
>
> > Hi Kevin,
> >
> > thanks for this constructive information.
> > I have not seen this behaviour on my system.
> > Which KDE/QT version are you using?
> >
> > If you use configure --enable-debug and recompile, you can
> > debug BT with KDevelop (frontend to gdb) to see where
> > the error is. Would be good if we could solve it before 1.0.
> >
> > Martin
> >
> > > In the current CVS build of bibletime there is a bug in the
> > > presenters that can cause a segfault when you choose NONE from the
> > > module selection button.  I also saw the same behavior in the
> > > beta1 build.  This happens for all of the
> > > presenters--CBiblePresenter, CCommentaryPresenter, and
> > > CLexiconPresenter.  Can anyone else verify this or is this some
> > > strange behavior for my system.
> > >
> > > If it is verifiable as a bug, I think I have a solution, but as I
> > > am fairly new to KDE/QT development I am not sure if it is the
> > > best solution or not.  Basically in CSwordPresenter.cpp if you
> > > change the line:
> > >
> > > CSwordPresenter::CSwordPresenter(ListCSwordModuleInfo useModules,
> > > CImportantClasses* importantClasses,QWidget *parent, const char
> > > *name ) : CPresenter(parent,name) {
> > >
> > > to be:
> > >
> > > CSwordPresenter::CSwordPresenter(ListCSwordModuleInfo useModules,
> > > CImportantClasses* importantClasses,QWidget *parent, const char
> > > *name ) : CPresenter(parent,name,0) {
> > >
> > > fixes the problem.  The only change is sending in 0 as the widget
> > > flag for the CPresenter which then gets used in the KMainWindow
> > > constructor instead of the default WDestructiveClose.  From
> > > kmainwindow.h it says:
> > >
> > >  *  Note that a KMainWindow per-default is created with the
> > >  *  WDestructiveClose flag, i.e. it is automatically destroyed when the
> > >  *  window is closed. If you do not want this behavior, specify 0 as
> > >  *  widget flag in the constructor.
> > >
> > > By sending 0 in it thus avoids the destructive close behavior and
> > > alleviates the segfault problem.  My biggest worry, being less
> > > than well versed in the kde api, is that by not using
> > > "destructive close" this is leaving objects and thus memory
> > > around that are not getting cleaned up properly.
> > >
> > > Any thoughts from those who are a little more knowledgable?  If
> > > this isn't reproduceable on anyone else's builds, any thoughts as
> > > to why I may be seeing it?  Thanks.
> > >
> > > Kevin
> > >
> >
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>