When I create a new title clip and want to exit the title editor using the Ok button, Kdenlive crashes.

I've pulled recent Kdenlive git master, as well as MLT master. My system is an upgraded Kubuntu 16.04 with open source AMD drivers.

OpenGL renderer:  "Gallium 0.4 on AMD PITCAIRN (DRM 2.43.0, LLVM 3.8.0)"
OpenGL ARG_SYNC:  true
OpenGL OpenGLES:  false

The backtrace is as follows:
#0  0x00007ffff3a24010 in QPixmapBlurFilter::radius() const () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#1  0x000000000080bf43 in TitleDocument::xml(QGraphicsRectItem*, QGraphicsRectItem*, bool) ()
#2  0x0000000000825045 in TitleWidget::xml() ()
#3  0x00000000006ac0f0 in ClipCreationDialog::createTitleClip(KdenliveDoc*, QStringList, QString, Bin*) ()
#4  0x00000000008a7cf4 in Bin::slotCreateProjectClip() ()
#5  0x000000000092fd74 in Bin::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) ()
#6  0x00007ffff2108fca in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007ffff3685412 in QAction::triggered(bool) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#8  0x00007ffff3687898 in QAction::activate(QAction::ActionEvent) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#9  0x00007ffff3809e22 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#10 0x00007ffff38100bc in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#11 0x00007ffff3814030 in QMenu::mouseReleaseEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#12 0x00007ffff36d1f88 in QWidget::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#13 0x00007ffff3814a83 in QMenu::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#14 0x00007ffff368f05c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#15 0x00007ffff3694c19 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#16 0x00007ffff20da62b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007ffff3693b32 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#18 0x00007ffff36ec8dd in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#19 0x00007ffff36eeb3b in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#20 0x00007ffff368f05c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#21 0x00007ffff3694516 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#22 0x00007ffff20da62b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007ffff241c521 in QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#24 0x00007ffff241e1e5 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#25 0x00007ffff2401f38 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#26 0x00007fffe558af10 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#27 0x00007fffee420127 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#28 0x00007fffee420380 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fffee42042c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007ffff2130a7f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#31 0x00007ffff20d7dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#32 0x00007ffff380ee10 in QMenu::exec(QPoint const&, QAction*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#33 0x00007ffff385119e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#34 0x00007ffff38520db in QToolButton::mousePressEvent(QMouseEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#35 0x00007ffff36d23cf in QWidget::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#36 0x00007ffff3852239 in QToolButton::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#37 0x00007ffff368f05c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#38 0x00007ffff3694c19 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#39 0x00007ffff20da62b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#40 0x00007ffff3693b32 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#41 0x00007ffff36ec57b in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#42 0x00007ffff36eeb3b in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#43 0x00007ffff368f05c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#44 0x00007ffff3694516 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#45 0x00007ffff20da62b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#46 0x00007ffff241c521 in QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#47 0x00007ffff241e1e5 in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#48 0x00007ffff2401f38 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#49 0x00007fffe558af10 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#50 0x00007fffee420127 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#51 0x00007fffee420380 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#52 0x00007fffee42042c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#53 0x00007ffff2130a7f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#54 0x00007ffff20d7dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#55 0x00007ffff20dfe8c in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#56 0x00000000008de5ee in main ()

Reproducible: Always

Steps to Reproduce:
1. Create a new title clip, the title editor will appear.
2. Add some text to title.
3. Exit title editor with "Ok" button.

Actual Results:  
Kdenlive crashes.

Expected Results:  
Kdenlive should not crash. :)