Help: MDI template crashes on Quit - bug in template, Qt, or KDE? Can anybody reproduce this?

[Pascal A. Niklaus]

Hi,

While porting code to the KDE MDI framework provided by KDevelop, I noticed 
that my app crashed *sometimes* when I quit. When I later tried to track 
down the bug I believed to be in my app, I finally noticed that it also 
occurred in the KDE MDI application framework as it is created 
automatically by KDevelop 1.4 (although it occurred more rarely, I had to 
start and quit the application up to 20 times to get the effect...).

My questions are:
- Can anyone else reproduce this problem? It seems to be related to freeing 
memory used by a QString... (freeing twice?). The crash can be reproduced 
by starting the app with F9, and immediately quitting in with CTRL-Q. As I 
said, it does not crash every time...
- Is it a problem with the KDevelop templates, with Qt, or with KDE ?

Any help with this is greatly appreciated

Thanks,

Pascal

------------ system related infos:

KDE 2.1, Qt 2.2.4, and KDevelop 1.4 were compiled from source with gcc 
2.95.2 on a SuSE7.0 linux system.
KDevelop 1.4 was downloaded from CVS, branch KDEVELOP_1_4_RELEASE or 
KDE_2_1_RELEASE...

Otherwise the installation is *very* stable... I'm therefore pretty 
confident that it is not a hardware (RAM) related issue.

Here's the backtrace (the crash is caused by a segment violation):

0x40c10019 in __wait4 () from /lib/libc.so.6
#0  0x40c10019 in __wait4 () from /lib/libc.so.6
#1  0x40c6d718 in __DTOR_END__ () from /lib/libc.so.6
#2  0x404a2d10 in KCrash::defaultCrashHandler ()
    from /usr/local/kde2/lib/libkdecore.so.3
#3  0x40bad9e8 in __restore ()
     at ../sysdeps/unix/sysv/linux/i386/sigaction.c:127
#4  0x40be11cf in free () at malloc.c:2952
#5  0x405581c4 in __builtin_delete () at ./cp/new2.cc:55
#6  0x40685f7a in QStringData::deleteSelf () from /usr/local/qt/lib/libqt.so.2
#7  0x8055181 in QString::~QString (this=0x808fd58, __in_chrg=2)
     at /usr/local/qt/include/qstring.h:652
#8  0x805603c in QValueListNode<QString>::~QValueListNode (this=0x808fd50,
     __in_chrg=3) at /usr/local/qt/include/qvaluelist.h:209
#9  0x8055f1c in QValueListPrivate<QString>::~QValueListPrivate (
     this=0x808fcf8, __in_chrg=3) at /usr/local/qt/include/qvaluelist.h:209
#10 0x8055d1b in QValueListPrivate<QString>::derefAndDelete (this=0x808fcf8)
     at /usr/local/qt/include/qvaluelist.h:198
#11 0x8055ae9 in QValueList<QString>::~QValueList (this=0x808fce8, __in_chrg=3)
     at /usr/local/qt/include/qvaluelist.h:322
#12 0x8055698 in QStringList::~QStringList (this=0x808fce8, __in_chrg=3)
     at kcite.cpp:247
#13 0x404d895d in QDict<QStringList>::deleteItem ()
    from /usr/local/kde2/lib/libkdecore.so.3
#14 0x40679e2a in QGDict::clear () from /usr/local/qt/lib/libqt.so.2
#15 0x40418bec in KStandardDirs::~KStandardDirs ()
    from /usr/local/kde2/lib/libkdecore.so.3
#16 0x404b0068 in KInstance::~KInstance ()
    from /usr/local/kde2/lib/libkdecore.so.3
#17 0x40451eac in KApplication::~KApplication ()
    from /usr/local/kde2/lib/libkdecore.so.3
#18 0x80530ee in main (argc=1, argv=0xbffff734) at main.cpp:74

--------- end of back trace ------



________________________________________________________

Present address:

Pascal Niklaus
Landcare Research
Private Bag 11 052
Palmerston North
New Zealand

Phone: +64 6 356 7154 (reception)
        +64 6 350 5799 3968 (direct)
Fax:   +64 6 355 9230

e-mail: <mailto:Pascal.Niklaus at unibas.ch>Pascal.Niklaus at unibas.ch or 
<mailto:Pascal.Niklaus at gmx.ch>Pascal.Niklaus at gmx.ch
_________________________________________________________
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/kdevelop/attachments/20010320/39ade2f7/attachment.html>