Version:           unspecified (using KDE 4.5.0) 
OS:                Linux

Commit 1168845 in 4.5 branch
"Backport: 2 bug fixes in Entiry management: do not crash when comparing empty entities and fix ref counting."
introduces crashes in libnepomuk.
Reverting to previous revision (1168450) fixes the problem.

Reproducible: Always

Steps to Reproduce:
1. Update kdelibs to 1168845 and rebuild
2. Start anything Nepomuk related (for instance dolphin --nofork with Nepomuk enabled)

Actual Results:  
Anything using Nepomuk crashes almost instantly (dolphin, nepomukservicestub)


Core was generated by `dolphin --nofork'.
Program terminated with signal 11, Segmentation fault.
#0  0x00007f6994385fe8 in QBasicAtomicInt::ref (this=0x400000008)
    at /usr/include/qt4/QtCore/qatomic_x86_64.h:121
121                      : "memory");
(gdb) bt
#0  0x00007f6994385fe8 in QBasicAtomicInt::ref (this=0x400000008)
    at /usr/include/qt4/QtCore/qatomic_x86_64.h:121
#1  0x00007f69943d4305 in QExplicitlySharedDataPointer (this=0x7fffa6c7e0d0, o=...)
    at /usr/include/qt4/QtCore/qshareddata.h:162
#2  0x00007f69943d3ca8 in Nepomuk::Types::EntityManager::getClass (this=0x1f4c760, uri=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/types/entitymanager.cpp:42
#3  0x00007f69943c620d in Class (this=0x7fffa6c7e140, uri=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/types/class.cpp:286
#4  0x00007f699439404b in Nepomuk::ResourceData::loadType (this=0x1f40570, storedType=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/core/resourcedata.cpp:331
#5  0x00007f6994394616 in Nepomuk::ResourceData::load (this=0x1f40570)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/core/resourcedata.cpp:380
#6  0x00007f6994393248 in Nepomuk::ResourceData::property (this=0x1f40570, uri=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/core/resourcedata.cpp:239
#7  0x00007f69943a51b2 in Nepomuk::Resource::property (this=0x1f391e0, uri=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/core/resource.cpp:271
#8  0x00007f69943a7374 in Nepomuk::Resource::label (this=0x1f391e0)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/core/resource.cpp:771
#9  0x00007f69943a5561 in Nepomuk::Resource::genericLabel (this=0x1f391e0)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/core/resource.cpp:347
#10 0x00007f69943bd736 in TagCheckBox (this=0x1f400f0, tag=..., tagWidget=0x1f34e70, 
    parent=0x1f38be0)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/ui/tagcheckbox.cpp:66
#11 0x00007f69943b73e5 in Nepomuk::TagWidgetPrivate::getTagCheckBox (this=0x1f34e70, tag=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/ui/tagwidget.cpp:168
#12 0x00007f69943b697a in Nepomuk::TagWidgetPrivate::buildTagHash (this=0x1f34e70, tags=...)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/ui/tagwidget.cpp:90
#13 0x00007f69943b68c3 in Nepomuk::TagWidgetPrivate::rebuild (this=0x1f34e70)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/ui/tagwidget.cpp:78
#14 0x00007f69943b6800 in Nepomuk::TagWidgetPrivate::init (this=0x1f34e70, parent=0x1f38be0)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/ui/tagwidget.cpp:67
#15 0x00007f69943b7c79 in TagWidget (this=0x1f38be0, parent=0x0)
    at /usr/portage/distfiles/svn-src/kdelibs-4.5.9999/kdelibs/nepomuk/ui/tagwidget.cpp:261
#16 0x00007f69938fa3ed in ?? () from /usr/lib/libkio.so.5
#17 0x00007f69938fa4c6 in ?? () from /usr/lib/libkio.so.5
#18 0x00007f69938fc034 in KFileMetaDataWidget::Private::Private(KFileMetaDataWidget*) ()
   from /usr/lib/libkio.so.5
#19 0x00007f69938fc108 in KFileMetaDataWidget::KFileMetaDataWidget(QWidget*) ()
   from /usr/lib/libkio.so.5
#20 0x00007f6994b46f64 in ?? () from /usr/lib/libdolphinprivate.so.4
#21 0x00007f6994b479f3 in ?? () from /usr/lib/libdolphinprivate.so.4
#22 0x00007f6994b4ab9d in ?? () from /usr/lib/libdolphinprivate.so.4
#23 0x00007f6994b22dc4 in DolphinDetailsView::DolphinDetailsView(QWidget*, DolphinViewController*, ViewModeController const*, DolphinSortFilterProxyModel*) () from /usr/lib/libdolphinprivate.so.4
#24 0x00007f6994b2f5f6 in DolphinView::ViewAccessor::createView(QWidget*, DolphinViewController*, ViewModeController const*, DolphinView::Mode) () from /usr/lib/libdolphinprivate.so.4
#25 0x00007f6994b2f7aa in DolphinView::createView() () from /usr/lib/libdolphinprivate.so.4
#26 0x00007f6994b3022d in DolphinView::applyViewProperties() ()
   from /usr/lib/libdolphinprivate.so.4
---Type <return> to continue, or q <return> to quit---
#27 0x00007f6994b30cd4 in DolphinView::DolphinView(QWidget*, KUrl const&, DolphinSortFilterProxyModel*) () from /usr/lib/libdolphinprivate.so.4
#28 0x00007f6995846938 in ?? () from /usr/lib/libkdeinit4_dolphin.so
#29 0x00007f69958434b6 in ?? () from /usr/lib/libkdeinit4_dolphin.so
#30 0x00007f69958374c9 in ?? () from /usr/lib/libkdeinit4_dolphin.so
#31 0x00007f6995837648 in ?? () from /usr/lib/libkdeinit4_dolphin.so
#32 0x00007f699332fd11 in KUniqueApplication::Private::_k_newInstanceNoFork() ()
   from /usr/lib/libkdeui.so.5
#33 0x00007f699332fd55 in KUniqueApplication::qt_metacall(QMetaObject::Call, int, void**) ()
   from /usr/lib/libkdeui.so.5
#34 0x00007f6991a9f162 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) ()
   from /usr/lib64/qt4/libQtCore.so.4
#35 0x00007f6991aa59e1 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#36 0x00007f6991a9bbbc in QObject::event(QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#37 0x00007f69926833e8 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
   from /usr/lib64/qt4/libQtGui.so.4
#38 0x00007f6992689152 in QApplication::notify(QObject*, QEvent*) ()
   from /usr/lib64/qt4/libQtGui.so.4
#39 0x00007f69933296d4 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#40 0x00007f6991a8da1a in QCoreApplication::notifyInternal(QObject*, QEvent*) ()
   from /usr/lib64/qt4/libQtCore.so.4
#41 0x00007f6991ab646c in ?? () from /usr/lib64/qt4/libQtCore.so.4
#42 0x00007f6991ab3339 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#43 0x00007f698e79f4ca in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#44 0x00007f698e7a2af1 in ?? () from /usr/lib/libglib-2.0.so.0
#45 0x00007f698e7a2cae in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#46 0x00007f6991ab30b0 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#47 0x00007f69927230be in ?? () from /usr/lib64/qt4/libQtGui.so.4
#48 0x00007f6991a8c672 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib64/qt4/libQtCore.so.4
#49 0x00007f6991a8c9c3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib64/qt4/libQtCore.so.4
#50 0x00007f6991a90f0f in QCoreApplication::exec() () from /usr/lib64/qt4/libQtCore.so.4
#51 0x00007f699584c4db in kdemain () from /usr/lib/libkdeinit4_dolphin.so
#52 0x00007f69954acbbd in __libc_start_main () from /lib/libc.so.6
#53 0x0000000000400799 in _start ()