Application: kde5-nm-connection-editor (5.4.2)

Qt Version: 5.5.1
Operating System: Linux 4.2.3-1-ARCH x86_64
Distribution (Platform): Archlinux Packages

-- Information about the crash:
- What I was doing when the application crashed:
In "Connection editor", I right-click and select "edit" on a recently created connection, that is configured for LEAP authentication. The configuration have a username field, and a password field. 
The username I use is an email-adress (including an "@" symbol)
The password is rather complex with all kinds of printable unicode characters. (I also tried a simple password, such as "qwerty" just to exclude "too complex passwords" as a cause. Made no difference)

- Unusual behavior I noticed:
Creating a new connection, and use "LEAP" under Wi-Fi Security works fine. But editing an existing one causes the crash.
Also, KDE refuses to even try connecting the LEAP-configured connection. It sits there doing nothing. As if I never connected at all.

- Custom settings of the application:
Wi-Fi Security set to "LEAP"

The crash can be reproduced every time.

-- Backtrace:
Application: Connection editor (kde5-nm-connection-editor), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fca59190840 (LWP 15021))]

Thread 2 (Thread 0x7fca442be700 (LWP 15023)):
#0  0x00007fca54f7218d in poll () from /usr/lib/libc.so.6
#1  0x00007fca4ed15ae2 in ?? () from /usr/lib/libxcb.so.1
#2  0x00007fca4ed17757 in xcb_wait_for_event () from /usr/lib/libxcb.so.1
#3  0x00007fca4598ce89 in ?? () from /usr/lib/libQt5XcbQpa.so.5
#4  0x00007fca5567396e in ?? () from /usr/lib/libQt5Core.so.5
#5  0x00007fca5196e4a4 in start_thread () from /usr/lib/libpthread.so.0
#6  0x00007fca54f7b13d in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7fca59190840 (LWP 15021)):
[KCrash Handler]
#5  0x00007fca58906be1 in NetworkManager::Security8021xSetting::password() const () from /usr/lib/libKF5NetworkManagerQt.so.6
#6  0x00007fca58beafcb in ?? () from /usr/lib/libplasmanm_editor.so
#7  0x00007fca58bfb219 in WifiSecurity::loadSecrets(QSharedPointer<NetworkManager::Setting> const&) () from /usr/lib/libplasmanm_editor.so
#8  0x00007fca58c173f1 in ConnectionDetailEditor::replyFinished(QDBusPendingCallWatcher*) () from /usr/lib/libplasmanm_editor.so
#9  0x00007fca55882fb7 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#10 0x00007fca5721db2f in QDBusPendingCallWatcher::finished(QDBusPendingCallWatcher*) () from /usr/lib/libQt5DBus.so.5
#11 0x00007fca5721f205 in ?? () from /usr/lib/libQt5DBus.so.5
#12 0x00007fca55883ff1 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#13 0x00007fca5658b01c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#14 0x00007fca565904f6 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#15 0x00007fca558549ab in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#16 0x00007fca55856da6 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQt5Core.so.5
#17 0x00007fca558aaf43 in ?? () from /usr/lib/libQt5Core.so.5
#18 0x00007fca50fe9dc7 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#19 0x00007fca50fea020 in ?? () from /usr/lib/libglib-2.0.so.0
#20 0x00007fca50fea0cc in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#21 0x00007fca558ab34f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#22 0x00007fca5585237a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#23 0x00007fca5585a33c in QCoreApplication::exec() () from /usr/lib/libQt5Core.so.5
#24 0x0000000000410c87 in main ()

Reported using DrKonqi