ubuntu-system-settings-wizard crashes/freezes when using the back button

[Michael Zanetti]

The settings wizard freezes/crashes when using the back button.

steps to reproduce:
* prepare a phone/tablet to make the welcome wizard appear on boot by flashing with --bootstrap (couldn't reproduce with only deleting the wizard-has-run file)
* boot the device
* in the wizard, press next until you reach the wifi setup page
* then press back.

This freezes it reliably here. Interesting fact is also that it doesn't recover after time, which makes it seem like its frozen indeed and not crashed. However, I do have _usr_bin_system-settings-wizard.32011.crash around every time this happens which indicates a crash too.

[Sebastien Bacher (seb128)]

Thank you for your bug report, could you add the backtrace of the .crash and from the process hanging?

[Andrea Cimitan (cimi)]

(gdb) bt full
#0 0xa9ace1ea in QHash<UnityMenuAction*, _GtkSimpleActionObserver*>::findNode(UnityMenuAction* const&, unsigned int*) const ()
   from /usr/lib/arm-linux-gnueabihf/libqmenumodel.so.0
No symbol table info available.
#1 0xa9acc920 in UnityMenuModel::unregisterAction(UnityMenuAction*) ()
   from /usr/lib/arm-linux-gnueabihf/libqmenumodel.so.0
No symbol table info available.
#2 0xa9ac9a26 in UnityMenuAction::~UnityMenuAction() ()
   from /usr/lib/arm-linux-gnueabihf/libqmenumodel.so.0
No symbol table info available.
#3 0xa9ae80c2 in QQmlPrivate::QQmlElement<UnityMenuAction>::~QQmlElement() ()
   from /usr/lib/arm-linux-gnueabihf/qt5/qml/QMenuModel/libqmenumodel-qml.so
No symbol table info available.
#4 0xb6dcd6f2 in QObjectPrivate::deleteChildren (this=this@entry=0xa1101500)
    at kernel/qobject.cpp:1935
        i = 14
#5 0xb6dd2fce in QObject::~QObject (this=<optimized out>,
    __in_chrg=<optimized out>) at kernel/qobject.cpp:1028
        d = <optimized out>
        __PRETTY_FUNCTION__ = "virtual QObject::~QObject()"
#6 0xb67e54d4 in QQuickItem::~QQuickItem() ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
No symbol table info available.
---Type <return> to continue, or q <return> to quit---
#7 0xb67f0902 in ?? () from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
No symbol table info available.
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

[Launchpad Janitor (janitor)]

This bug was fixed in the package qmenumodel - 0.2.7+14.10.20140704-0ubuntu1

---------------
qmenumodel (0.2.7+14.10.20140704-0ubuntu1) utopic; urgency=low

  [ Charles Kerr ]
  * Fix a dangling UnityMenuAction pointer by ensuring it's registered
    with only one menu at a time. (LP: #1282282)

  [ Nick Dedekind ]
  * Unset the UnityMenuActions::model when destroying UnityMenuModel
    (LP: #1334203)
 -- Ubuntu daily release <email address hidden> Fri, 04 Jul 2014 07:38:11 +0000