plasma-desktop crashes after upgrade to 4.6-rc2

Hello.

plasma-desktop crashes at login and after 'kstart plasma-desktop'.

KCrash report:
-----------------------------------------------------------
Application: Оболочка Plasma (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fcda7ba27a0 (LWP 17180))]

Thread 4 (Thread 0x7fcd96b01700 (LWP 17183)):
#0 0xffffffffff60017b in ?? ()
#1 0x00007fcd96b00ad0 in ?? ()
#2 0x00007fff66b66852 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 3 (Thread 0x7fcd96300700 (LWP 17184)):
#0 0x00000031150df2c3 in select () at ../sysdeps/unix/syscall-template.S:82
#1 0x000000311bd9276e in qt_safe_select (nfds=29, fdread=0x20d5d30, fdwrite=0x20d5fc8, fdexcept=0x20d6260, orig_timeout=0x0) at kernel/qcore_unix.cpp:82
#2 0x000000311bd97beb in QEventDispatcherUNIXPrivate::doSelect (this=0x20d5b70, flags=<value optimized out>, timeout=<value optimized out>) at kernel/qeventdispatcher_unix.cpp:219
#3 0x000000311bd9881b in QEventDispatcherUNIX::processEvents (this=0x1ef4550, flags=) at kernel/qeventdispatcher_unix.cpp:919
#4 0x000000311bd67a02 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#5 0x000000311bd67dec in QEventLoop::exec (this=0x7fcd962ffcd0, flags=) at kernel/qeventloop.cpp:201
#6 0x000000311bc722fd in QThread::exec (this=<value optimized out>) at thread/qthread.cpp:490
#7 0x00007fcdaa60fb6c in Herqq::Upnp::HControlPointThread::run() () from /usr/lib/libHUpnp.so.0
#8 0x000000311bc7527e in QThreadPrivate::start (arg=0x20b1d70) at thread/qthread_unix.cpp:266
#9 0x00007fcdab83f953 in ?? () from /usr/lib/nvidia-current/libGL.so.1
#10 0x0000003115c07971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#11 0x00000031150e692d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fcd9512a700 (LWP 17185)):
#0 0xffffffffff60017b in ?? ()
#1 0x00007fcd951299f0 in ?? ()
#2 0x00007fff66b66852 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

Thread 1 (Thread 0x7fcda7ba27a0 (LWP 17180)):
[KCrash Handler]
#6 Plasma::Containment::setScreen (this=0x0, newScreen=0, newDesktop=-1) at ../../plasma/containment.cpp:959
#7 0x00007fcdae7bfa62 in Activity::containmentForScreen (this=0x29e6c70, screen=0, desktop=-1) at ../../../../plasma/desktop/shell/activity.cpp:191
#8 0x00007fcdae7bfd97 in Activity::activateContainment (this=0x0, screen=0, desktop=-1) at ../../../../plasma/desktop/shell/activity.cpp:205
#9 0x00007fcdae7bfe54 in Activity::checkScreens (this=0x29e6c70) at ../../../../plasma/desktop/shell/activity.cpp:235
#10 0x00007fcdae7c014f in Activity::opened (this=0x29e6c70) at ../../../../plasma/desktop/shell/activity.cpp:404
#11 0x00007fcdae7c0456 in Activity::ensureActive (this=0x29e6c70) at ../../../../plasma/desktop/shell/activity.cpp:217
#12 0x00007fcdae7c9788 in DesktopCorona::activityAdded (this=0x1723220, id=...) at ../../../../plasma/desktop/shell/desktopcorona.cpp:687
#13 0x00007fcdae7cbdc6 in DesktopCorona::checkActivities (this=0x1723220) at ../../../../plasma/desktop/shell/desktopcorona.cpp:578
#14 0x00007fcdae7eec57 in PlasmaApp::corona (this=0x1669220) at ../../../../plasma/desktop/shell/plasmaapp.cpp:796
#15 0x00007fcdae7eef7c in PlasmaApp::setupDesktop (this=0x1669220) at ../../../../plasma/desktop/shell/plasmaapp.cpp:299
#16 0x00007fcdae7f197c in PlasmaApp::qt_metacall (this=0x1669220, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x16f1120) at ./plasmaapp.moc:156
#17 0x000000311bd7abde in QObject::event (this=0x1669220, e=0x0) at kernel/qobject.cpp:1219
#18 0x000000311cfbb186 in QApplication::event (this=0x1669220, e=0x1728f50) at kernel/qapplication.cpp:2439
#19 0x000000311cfb7fdc in QApplicationPrivate::notify_helper (this=0x16828c0, receiver=0x1669220, e=0x1728f50) at kernel/qapplication.cpp:4396
#20 0x000000311cfbdaed in QApplication::notify (this=0x1669220, receiver=0x1669220, e=0x1728f50) at kernel/qapplication.cpp:4277
#21 0x00007fcdacde4a36 in KApplication::notify (this=0x1669220, receiver=0x1669220, event=0x1728f50) at ../../kdeui/kernel/kapplication.cpp:311
#22 0x000000311bd68cdc in QCoreApplication::notifyInternal (this=0x1669220, receiver=0x1669220, event=0x1728f50) at kernel/qcoreapplication.cpp:732
#23 0x000000311bd6bc22 in sendEvent (receiver=0x0, event_type=<value optimized out>, data=0x15deba0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#24 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0x15deba0) at kernel/qcoreapplication.cpp:1373
#25 0x000000311d06ba44 in sendPostedEvents (this=<value optimized out>, flags=) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#26 QEventDispatcherX11::processEvents (this=<value optimized out>, flags=) at kernel/qeventdispatcher_x11.cpp:75
#27 0x000000311bd67a02 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#28 0x000000311bd67dec in QEventLoop::exec (this=0x7fff66ac30c0, flags=) at kernel/qeventloop.cpp:201
#29 0x000000311bd6bebb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1009
#30 0x00007fcdae7d4ca3 in kdemain (argc=<value optimized out>, argv=<value optimized out>) at ../../../../plasma/desktop/shell/main.cpp:118
#31 0x000000311501ed8e in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fff66ac3498) at libc-start.c:226
#32 0x0000000000400669 in _start ()
-----------------------------------------------------------

The problem is in Thread 1.
The most interesting lines are:
#24 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0x15deba0) at kernel/qcoreapplication.cpp:1373
#23 0x000000311bd6bc22 in sendEvent (receiver=0x0, event_type=<value optimized out>, data=0x15deba0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#17 0x000000311bd7abde in QObject::event (this=0x1669220, e=0x0) at kernel/qobject.cpp:1219
#8 0x00007fcdae7bfd97 in Activity::activateContainment (this=0x0, screen=0, desktop=-1) at ../../../../plasma/desktop/shell/activity.cpp:205#6 Plasma::Containment::setScreen (this=0x0, newScreen=0, newDesktop=-1) at ../../plasma/containment.cpp:959
#6 Plasma::Containment::setScreen (this=0x0, newScreen=0, newDesktop=-1) at ../../plasma/containment.cpp:959

So Activity::activateContainment is called with NULL pointer.