Crash in preference handling

I am seeing a crash in the preference handling.

Steps to reproduce:
1. Open any project (e.g. Qt Creator) in Qt Creator.
2. Open a source file belonging to that project.
3. Close the project, keep the file open.
4. Click into the editor with the file and hit the return key.

Actual result:
Qt Creator crashes

Expected result:
Qt Creator does not crash.

Here is the backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x00007fffef770242 in TextEditor::IFallbackPreferences::currentFallback (this=
0x47004f004c0000)
at /home/code/src/creator-2.3/src/plugins/texteditor/ifallbackpreferences.cpp:152
152 return d->m_currentFallback;
(gdb) bt
#0 0x00007fffef770242 in TextEditor::IFallbackPreferences::currentFallback (
this=0x47004f004c0000)
at /home/code/src/creator-2.3/src/plugins/texteditor/ifallbackpreferences.cpp:152
#1 0x00007fffef7701f2 in TextEditor::IFallbackPreferences::currentPreferences (
this=0x1531ab0)
at /home/code/src/creator-2.3/src/plugins/texteditor/ifallbackpreferences.cpp:140
#2 0x00007fffef77019f in TextEditor::IFallbackPreferences::currentValue (this=0x1531ab0)
at /home/code/src/creator-2.3/src/plugins/texteditor/ifallbackpreferences.cpp:134
#3 0x00007fffee2475e6 in CppTools::CppCodeStylePreferences::currentSettings (this=
0x1531ab0)
at /home/code/src/creator-2.3/src/plugins/cpptools/cppcodestylepreferences.cpp:86
#4 0x00007fffee1f9415 in CppTools::CppQtStyleIndenter::codeStyleSettings (
this=0x4d9e0b0)
at /home/code/src/creator-2.3/src/plugins/cpptools/cppqtstyleindenter.cpp:163
#5 0x00007fffee1f8e91 in CppTools::CppQtStyleIndenter::indentBlock (this=0x4d9e0b0,
doc=0x4daf530, block=..., typedChar=..., editor=0x4d34980)
at /home/code/src/creator-2.3/src/plugins/cpptools/cppqtstyleindenter.cpp:99
#6 0x00007fffee1f9379 in CppTools::CppQtStyleIndenter::indent (this=0x4d9e0b0,
doc=0x4daf530, cursor=..., typedChar=..., editor=0x4d34980)
at /home/code/src/creator-2.3/src/plugins/cpptools/cppqtstyleindenter.cpp:148
#7 0x00007fffef6b7902 in TextEditor::BaseTextEditorWidget::indent (this=0x4d34980,
doc=0x4daf530, cursor=..., typedChar=...)
at /home/code/src/creator-2.3/src/plugins/texteditor/basetexteditor.cpp:4568
#8 0x00007fffef6a4a13 in TextEditor::BaseTextEditorWidget::keyPressEvent (
this=0x4d34980, e=0x7fffffffcd70)
at /home/code/src/creator-2.3/src/plugins/texteditor/basetexteditor.cpp:1579
#9 0x00007fffec486f03 in CppEditor::Internal::CPPEditorWidget::keyPressEvent (this=
0x4d34980, e=0x7fffffffcd70)
at /home/code/src/creator-2.3/src/plugins/cppeditor/cppeditor.cpp:1687
#10 0x00007ffff6cd2ca2 in QWidget::event(QEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#11 0x00007ffff7081be6 in QFrame::event(QEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#12 0x00007ffff70fd28b in QAbstractScrollArea::event(QEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#13 0x00007ffff7119765 in QPlainTextEdit::event(QEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#14 0x00007fffef6a73e2 in TextEditor::BaseTextEditorWidget::event (this=0x4d34980,
e=0x7fffffffcd70)
at /home/code/src/creator-2.3/src/plugins/texteditor/basetexteditor.cpp:2037
#15 0x00007fffec48670b in CppEditor::Internal::CPPEditorWidget::event (this=0x4d34980,
e=0x7fffffffcd70)
at /home/code/src/creator-2.3/src/plugins/cppeditor/cppeditor.cpp:1621
#16 0x00007ffff6c85334 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#17 0x00007ffff6c89e36 in QApplication::notify(QObject*, QEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#18 0x00007ffff63f8d3c in QCoreApplication::notifyInternal(QObject*, QEvent*) ()
from /home/code/build/qt/lib/libQtCore.so.4
#19 0x00007ffff6d1d1c9 in QKeyMapper::sendKeyEvent(QWidget*, bool, QEvent::Type, int, QFlags<Qt::KeyboardModifier>, QString const&, bool, int, unsigned int, unsigned int, unsigned int, bool*) () from /home/code/build/qt/lib/libQtGui.so.4
#20 0x00007ffff6d1d5f8 in QKeyMapperPrivate::translateKeyEvent(QWidget*, _XEvent const*, bool) () from /home/code/build/qt/lib/libQtGui.so.4
#21 0x00007ffff6cfbafe in QApplication::x11ProcessEvent(_XEvent*) ()
from /home/code/build/qt/lib/libQtGui.so.4
#22 0x00007ffff6d212d4 in QEventDispatcherX11::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/code/build/qt/lib/libQtGui.so.4
#23 0x00007ffff63f7e92 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/code/build/qt/lib/libQtCore.so.4
#24 0x00007ffff63f8137 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /home/code/build/qt/lib/libQtCore.so.4
#25 0x00007ffff63fc9db in QCoreApplication::exec() ()
from /home/code/build/qt/lib/libQtCore.so.4
#26 0x000000000040a8de in main (argc=1, argv=0x7fffffffe2b8)
at ../../../../src/creator-2.3/src/app/main.cpp:386