Created attachment 73074 [details]
Opción Preferencias del sistema

Desde Kubuntu 12.04 con KDE 4.8.5, actualice KDE 4.9, al abrir la ventana "Preferencias del sistema", opción "Apariencia de Trabajo", esta se cae por el error informado.

Created attachment 73075 [details]
Error en preferencias del sistema

Pantalla que despliega el error

It crashes in
const int newWidth = m_ui->decorationList->rootObject()->property("width").toInt();
because rootObject() is 0x0 (while the rootContext() is still valid?)

@Walter: you did certainly not experience this very crash on 4.8.x (code is new) but when does this happen (activating the module, closing it, resizing the window or similar)?

Whatever you do, you fall .... This happened to upgrade KDE 4.8.5 to 4.9 ....

Ok, but the remaining questions are
- whether you can reproduce it
- what kind of action causes it (right now i can only think of one quite unlikely incident that could lead to this condition)

The error is very simple to play...
1.-Select the KDE APPLICATION LAUCHER.
2.-Select the System Preferences.
3.-Select the Workspace Appearance, 

Note1: Occurs only in kde 4.9
Note2: Delete styles the KWIN, the problem continues
Note3: In previous comments, attach images.


Adjunt Error

Application: Preferencias del sistema (systemsettings), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0xb1d16740 (LWP 26703))]

Thread 3 (Thread 0xae70db40 (LWP 26704)):
#0  0xb2e3cdcd in clock_gettime () from /lib/i386-linux-gnu/librt.so.1
#1  0xb5fec315 in do_gettime (frac=0xae70cfb0, sec=0xae70cfa8) at tools/qelapsedtimer_unix.cpp:123
#2  qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#3  0xb60d6226 in QTimerInfoList::updateCurrentTime (this=0xade02074) at kernel/qeventdispatcher_unix.cpp:343
#4  0xb60d657a in QTimerInfoList::timerWait (this=0xade02074, tm=...) at kernel/qeventdispatcher_unix.cpp:450
#5  0xb60d4e23 in timerSourcePrepareHelper (src=<optimized out>, timeout=0xae70d0bc) at kernel/qeventdispatcher_glib.cpp:136
#6  0xb60d4ebd in timerSourcePrepare (source=0xade02040, timeout=<optimized out>) at kernel/qeventdispatcher_glib.cpp:169
#7  0xb3061872 in g_main_context_prepare () from /lib/i386-linux-gnu/libglib-2.0.so.0
#8  0xb3061faf in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#9  0xb3062201 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#10 0xb60d58e7 in QEventDispatcherGlib::processEvents (this=0xade00468, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#11 0xb60a150d in QEventLoop::processEvents (this=0xae70d240, flags=...) at kernel/qeventloop.cpp:149
#12 0xb60a17a9 in QEventLoop::exec (this=0xae70d240, flags=...) at kernel/qeventloop.cpp:204
#13 0xb5f8a94c in QThread::exec (this=0x90823f0) at thread/qthread.cpp:501
#14 0xb607eb5d in QInotifyFileSystemWatcherEngine::run (this=0x90823f0) at io/qfilesystemwatcher_inotify.cpp:248
#15 0xb5f8dde0 in QThreadPrivate::start (arg=0x90823f0) at thread/qthread_unix.cpp:298
#16 0xb3133d4c in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#17 0xb5d86ace in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 2 (Thread 0xaddabb40 (LWP 26705)):
#0  0xb77cb424 in __kernel_vsyscall ()
#1  0xb313796b in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i386-linux-gnu/libpthread.so.0
#2  0xb5d943dc in pthread_cond_wait () from /lib/i386-linux-gnu/libc.so.6
#3  0xb4232029 in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#4  0xb423206f in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#5  0xb3133d4c in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#6  0xb5d86ace in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 1 (Thread 0xb1d16740 (LWP 26703)):
[KCrash Handler]
#7  data (this=0x4) at ../../include/QtCore/../../src/corelib/tools/qscopedpointer.h:135
#8  qGetPtrHelper<QScopedPointer<QObjectData> > (p=...) at ../../include/QtCore/../../src/corelib/global/qglobal.h:2430
#9  d_func (this=0x0) at ../../include/QtCore/../../src/corelib/kernel/qobject.h:115
#10 QObject::property (this=0x0, name=0xaddf4e3c "width") at kernel/qobject.cpp:3740
#11 0xaddd8dec in KWin::KWinDecorationModule::updatePreviews (this=0x9083ef0) at ../../../../kwin/kcmkwin/kwindecoration/kwindecoration.cpp:414
#12 0xb60b4c01 in QMetaCallEvent::placeMetaCall (this=0x918a3b0, object=0x9083ef0) at kernel/qobject.cpp:525
#13 0xb60bdc7b in QObject::event (this=0x9083ef0, e=0x918a3b0) at kernel/qobject.cpp:1195
#14 0xb66e9e62 in QWidget::event (this=0x9083ef0, event=0x918a3b0) at kernel/qwidget.cpp:8821
#15 0xb668fed4 in notify_helper (e=0x918a3b0, receiver=0x9083ef0, this=0x8c8d628) at kernel/qapplication.cpp:4559
#16 QApplicationPrivate::notify_helper (this=0x8c8d628, receiver=0x9083ef0, e=0x918a3b0) at kernel/qapplication.cpp:4531
#17 0xb66953a2 in QApplication::notify (this=0x8c8d628, receiver=0x9083ef0, e=0x918a3b0) at kernel/qapplication.cpp:4524
#18 0xb7214e41 in KApplication::notify (this=0xbfe3472c, receiver=0x9083ef0, event=0x918a3b0) at ../../kdeui/kernel/kapplication.cpp:311
#19 0xb60a297e in QCoreApplication::notifyInternal (this=0xbfe3472c, receiver=0x9083ef0, event=0x918a3b0) at kernel/qcoreapplication.cpp:876
#20 0xb60a6ad8 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#21 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x8c4f130) at kernel/qcoreapplication.cpp:1500
#22 0xb60a6e0c in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1393
#23 0xb60d5494 in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#24 postEventSourceDispatch (s=0x8c82610) at kernel/qeventdispatcher_glib.cpp:279
#25 0xb3061d86 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#26 0xb3062125 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#27 0xb3062201 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#28 0xb60d5887 in QEventDispatcherGlib::processEvents (this=0x8c4feb8, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#29 0xb6748aaa in QGuiEventDispatcherGlib::processEvents (this=0x8c4feb8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#30 0xb60a150d in QEventLoop::processEvents (this=0xbfe34684, flags=...) at kernel/qeventloop.cpp:149
#31 0xb60a17a9 in QEventLoop::exec (this=0xbfe34684, flags=...) at kernel/qeventloop.cpp:204
#32 0xb60a6eba in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#33 0xb668da74 in QApplication::exec () at kernel/qapplication.cpp:3820
#34 0x08050438 in main (argc=152592064, argv=0x0) at ../../../systemsettings/app/main.cpp:49

please try running (from konsole)

    QT_NO_GLIB=1 kcmshell4 kwindecoration

if that works also just

     kcmshell4 kwindecoration

this has nothing to do with the installed decorations but means that the rootObject of the DeclarativeView is 0x0 

@Martin (and note to self)
the previews should be regenerated through a queued invocation - this *could* be related to bug #303244 and a similar crash we've had before.

the execution of the command "QT_NO_GLIB = 1 kcmshell4 kwindecoration " and "kcmshell4 kwindecoration" gave the same error.

Log execution command: 
# QT_NO_GLIB=1 kcmshell4 kwindecoration
kcmshell(19716)/kwin KDecorationPlugins::canLoad: "****** The library /usr/lib/kde4/kwin3_qtcurve.so has no API version ******" 
kcmshell(19716)/kwin KDecorationPlugins::canLoad: ****** Please use the KWIN_DECORATION macro in extern "C" to get this decoration loaded in future versions of kwin 
QObject::connect: Cannot connect (null)::currentIndexChanged() to KWin::KWinDecorationModule::slotSelectionChanged()
QObject::connect: Cannot connect (null)::widthChanged() to KWin::KWinDecorationModule::updatePreviewWidth()
QObject::connect: Cannot connect (null)::contentYChanged() to KWin::KWinDecorationModule::updateScrollbarValue()
QObject::connect: Cannot connect (null)::contentHeightChanged() to KWin::KWinDecorationModule::updateScrollbarRange()
KCrash: Application 'kcmshell4' crashing...
KCrash: Attempting to start /usr/lib/kde4/libexec/drkonqi from kdeinit
sock_file=/home/hsaez/.kde/socket-hsaez-schema/kdeinit4__0

[1]+  Detenido                QT_NO_GLIB=1 kcmshell4 kwindecoration


Log Error: 
Application: Módulo de control de KDE (kcmshell4), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0xb55d8980 (LWP 19716))]

Thread 3 (Thread 0xb17c1b40 (LWP 19717)):
#0  0xb76fe424 in __kernel_vsyscall ()
#1  0xb59bb96b in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i386-linux-gnu/libpthread.so.0
#2  0xb76293dc in pthread_cond_wait () from /lib/i386-linux-gnu/libc.so.6
#3  0xb1e84029 in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#4  0xb1e8406f in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#5  0xb59b7d4c in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#6  0xb761bace in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 2 (Thread 0xb09a9b40 (LWP 19718)):
#0  0xb76fe424 in __kernel_vsyscall ()
#1  0xb7614af1 in select () from /lib/i386-linux-gnu/libc.so.6
#2  0xb6c2e42a in qt_safe_select (nfds=15, fdread=0xb000058c, fdwrite=0xb00007a0, fdexcept=0xb00009b4, orig_timeout=0x0) at kernel/qcore_unix.cpp:83
#3  0xb6c32a1b in QEventDispatcherUNIX::select (this=0xb0000488, nfds=15, readfds=0xb000058c, writefds=0xb00007a0, exceptfds=0xb00009b4, timeout=0x0) at kernel/qeventdispatcher_unix.cpp:639
#4  0xb6c33d2f in QEventDispatcherUNIXPrivate::doSelect (this=0xb0000498, flags=..., timeout=0x0) at kernel/qeventdispatcher_unix.cpp:223
#5  0xb6c341f4 in QEventDispatcherUNIX::processEvents (this=0xb0000488, flags=...) at kernel/qeventdispatcher_unix.cpp:926
#6  0xb6bfd50d in QEventLoop::processEvents (this=0xb09a9240, flags=...) at kernel/qeventloop.cpp:149
#7  0xb6bfd7a9 in QEventLoop::exec (this=0xb09a9240, flags=...) at kernel/qeventloop.cpp:204
#8  0xb6ae694c in QThread::exec (this=0x9280208) at thread/qthread.cpp:501
#9  0xb6bdab5d in QInotifyFileSystemWatcherEngine::run (this=0x9280208) at io/qfilesystemwatcher_inotify.cpp:248
#10 0xb6ae9de0 in QThreadPrivate::start (arg=0x9280208) at thread/qthread_unix.cpp:298
#11 0xb59b7d4c in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#12 0xb761bace in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 1 (Thread 0xb55d8980 (LWP 19716)):
[KCrash Handler]
#7  data (this=0x4) at ../../include/QtCore/../../src/corelib/tools/qscopedpointer.h:135
#8  qGetPtrHelper<QScopedPointer<QObjectData> > (p=...) at ../../include/QtCore/../../src/corelib/global/qglobal.h:2430
#9  d_func (this=0x0) at ../../include/QtCore/../../src/corelib/kernel/qobject.h:115
#10 QObject::property (this=0x0, name=0xb23ddef5 "contentHeight") at kernel/qobject.cpp:3740
#11 0xb23c207c in KWin::KWinDecorationModule::updateScrollbarRange (this=0x8fdc7f8) at ../../../../kwin/kcmkwin/kwindecoration/kwindecoration.cpp:441
#12 0xb23c2478 in KWin::KWinDecorationModule::eventFilter (this=0x8fdc7f8, o=0x8fdc7e0, e=0xbfb802d4) at ../../../../kwin/kcmkwin/kwindecoration/kwindecoration.cpp:367
#13 0xb6bfeb16 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x8f9ed90, receiver=0x8fdc7e0, event=0xbfb802d4) at kernel/qcoreapplication.cpp:986
#14 0xb60e8ea2 in notify_helper (e=0xbfb802d4, receiver=0x8fdc7e0, this=0x8f9ed90) at kernel/qapplication.cpp:4555
#15 QApplicationPrivate::notify_helper (this=0x8f9ed90, receiver=0x8fdc7e0, e=0xbfb802d4) at kernel/qapplication.cpp:4531
#16 0xb60ee3a2 in QApplication::notify (this=0x8f9ed90, receiver=0x8fdc7e0, e=0xbfb802d4) at kernel/qapplication.cpp:4524
#17 0xb729ce41 in KApplication::notify (this=0xbfb80a78, receiver=0x8fdc7e0, event=0xbfb802d4) at ../../kdeui/kernel/kapplication.cpp:311
#18 0xb6bfe97e in QCoreApplication::notifyInternal (this=0xbfb80a78, receiver=0x8fdc7e0, event=0xbfb802d4) at kernel/qcoreapplication.cpp:876
#19 0xb613d697 in sendEvent (event=0xbfb802d4, receiver=0x8fdc7e0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#20 QWidgetPrivate::sendPendingMoveAndResizeEvents (this=0x922c1b0, recursive=false, disableUpdates=<optimized out>) at kernel/qwidget.cpp:7432
#21 0xb6146158 in QWidgetPrivate::show_helper (this=0x922c1b0) at kernel/qwidget.cpp:7483
#22 0xb61465c1 in QWidget::setVisible (this=0x8fdc7e0, visible=true) at kernel/qwidget.cpp:7764
#23 0xb61460e8 in show (this=0x8fdc7e0) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:494
#24 QWidgetPrivate::showChildren (this=0x8fdd5f0, spontaneous=false) at kernel/qwidget.cpp:7852
#25 0xb6146180 in QWidgetPrivate::show_helper (this=0x8fdd5f0) at kernel/qwidget.cpp:7489
#26 0xb61465c1 in QWidget::setVisible (this=0x8fdcd08, visible=true) at kernel/qwidget.cpp:7764
#27 0xb61460e8 in show (this=0x8fdcd08) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:494
#28 QWidgetPrivate::showChildren (this=0x8fdc898, spontaneous=false) at kernel/qwidget.cpp:7852
#29 0xb6146180 in QWidgetPrivate::show_helper (this=0x8fdc898) at kernel/qwidget.cpp:7489
#30 0xb61465c1 in QWidget::setVisible (this=0x8fdc7f8, visible=true) at kernel/qwidget.cpp:7764
#31 0xb61460e8 in show (this=0x8fdc7f8) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:494
#32 QWidgetPrivate::showChildren (this=0x9102cb0, spontaneous=false) at kernel/qwidget.cpp:7852
#33 0xb6146180 in QWidgetPrivate::show_helper (this=0x9102cb0) at kernel/qwidget.cpp:7489
#34 0xb6145f64 in QWidgetPrivate::show_recursive (this=0x9102cb0) at kernel/qwidget.cpp:7413
#35 0xb6146069 in QWidgetPrivate::showChildren (this=0x90aef80, spontaneous=false) at kernel/qwidget.cpp:7850
#36 0xb6146180 in QWidgetPrivate::show_helper (this=0x90aef80) at kernel/qwidget.cpp:7489
#37 0xb6145f64 in QWidgetPrivate::show_recursive (this=0x90aef80) at kernel/qwidget.cpp:7413
#38 0xb6146069 in QWidgetPrivate::showChildren (this=0x90ca308, spontaneous=false) at kernel/qwidget.cpp:7850
#39 0xb6146180 in QWidgetPrivate::show_helper (this=0x90ca308) at kernel/qwidget.cpp:7489
#40 0xb61465c1 in QWidget::setVisible (this=0x90c7c38, visible=true) at kernel/qwidget.cpp:7764
#41 0xb61460e8 in show (this=0x90c7c38) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:494
#42 QWidgetPrivate::showChildren (this=0x90ced38, spontaneous=false) at kernel/qwidget.cpp:7852
#43 0xb6146180 in QWidgetPrivate::show_helper (this=0x90ced38) at kernel/qwidget.cpp:7489
#44 0xb61465c1 in QWidget::setVisible (this=0x90b6d60, visible=true) at kernel/qwidget.cpp:7764
#45 0xb663c564 in QDialog::setVisible (this=0x90b6d60, visible=true) at dialogs/qdialog.cpp:741
#46 0xb663b087 in show (this=0x90b6d60) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:494
#47 QDialog::exec (this=0x90b6d60) at dialogs/qdialog.cpp:545
#48 0xb76f7b39 in kdemain (_argc=2, _argv=0xbfb80d14) at ../../kcmshell/main.cpp:292
#49 0x0804850b in main (argc=2, argv=0xbfb80d14) at kcmshell4_dummy.cpp:3

I could only imagine the qml file is not installed/found/loaded

Please check for the existence of kwin/kcm_kwindecoration/main.qml in one of the paths suggested by kde4-config --path data and ensure you've read permissions on it

Execute command "kde4-config --path data" and no route exists in the directory and file "kwin/kcm_kwindecoration/main.qml"

Log Command: kde4-config --path data
/home/hsaez/.kde/share/apps/:/usr/share/kubuntu-default-settings/kde4-profile/default/share/apps/:/usr/share/kde4/apps/

(In reply to comment #10)
> Execute command "kde4-config --path data" and no route exists in the
> directory and file "kwin/kcm_kwindecoration/main.qml"
> 
> Log Command: kde4-config --path data
> /home/hsaez/.kde/share/apps/:/usr/share/kubuntu-default-settings/kde4-
> profile/default/share/apps/:/usr/share/kde4/apps/

To make that very clear: there is none of

/home/hsaez/.kde/share/apps/kwin/kcm_kwindecoration/main.qml
/usr/share/kubuntu-default-settings/kde4-profile/default/share/apps/kwin/kcm_kwindecoration/main.qml
/usr/share/kde4/apps/kwin/kcm_kwindecoration/main.qml

Correct? That's a bug in your installation / distribution.
We shall prevent the crash but the dialog will not work either w/o this file.

Exactly. What do I do?

re-install kde-window-manager-common and hope it's complete.

If your distro packages aren't broken (/usr/share/kde4/apps/kwin/kcm_kwindecoration/main.qml seems there) there's a local issue with the installation process (out of space, incomplete installation due to crash etc.) that needs to be fixed first.

Excellent Thomas, to re-install "kde-window-manager-common", the error was corrected.

Thanks to all the team for their support ...
It is evident that the KDE community is best.

changing to invalid as it is actually not fixed.

Invalid because I think it doesn't make much sense to try to make the KCM work without the QML file.

Git commit 33c5af3abd8d64fbb0f21d3f33bbc0ba1a7b8588 by Thomas Lübking.
Committed on 17/08/2012 at 13:19.
Pushed by luebking into branch 'KDE/4.9'.

Ensure main.qml presence
REVIEW: 106062
FIXED-IN: 4.9.1

M  +11   -1    kwin/kcmkwin/kwindecoration/kwindecoration.cpp

http://commits.kde.org/kde-workspace/33c5af3abd8d64fbb0f21d3f33bbc0ba1a7b8588

Git commit 6acbd605bd28186f71bede467a5183881ca82fe9 by Thomas Lübking.
Committed on 17/08/2012 at 13:19.
Pushed by luebking into branch 'master'.

Ensure main.qml presence
REVIEW: 106062
FIXED-IN: 4.9.1

M  +11   -1    kwin/kcmkwin/kwindecoration/kwindecoration.cpp

http://commits.kde.org/kde-workspace/6acbd605bd28186f71bede467a5183881ca82fe9