[panel] Setting the value of com.canonical.Unity2d.Panel:applets crashes the panel

[Olivier Tilloy]

This is on natty with the latest daily packages from the PPA (3.8.16-0ubuntu1~bzr675).

To reproduce, just invoke the following command in a terminal while the panel is running:

    gsettings set com.canonical.Unity2d.Panel applets "['\!homebutton', '\!separator', 'appname', '\!legacytray', 'indicator']"

(this is just setting the value of the key to its default value, not actually changing anything, but setting a different value also causes the crash)

[Olivier Tilloy (osomon)]

Here is the stack trace of the relevant thread when observing the crash in gdb:

Thread 1 (Thread 0x7ffff7fb09e0 (LWP 10229)):
#0 0x00007ffff6aa33dc in QConf::notify(char const*) () from /usr/lib/libdconf-qt.so.0
#1 0x00007ffff689a9f9 in dconf_dbus_emit_change (dcdbc=0x87e640, key=0xcfe9f4 "/com/canonical/unity-2d/panel/applets")
    at dconf-dbus-1.c:467
#2 0x00007ffff689ab5b in dconf_dbus_client_filter (connection=<value optimized out>, message=0xcfe880, user_data=0x87e640)
    at dconf-dbus-1.c:656
#3 0x00007ffff63e9ac6 in dbus_connection_dispatch () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#4 0x00007ffff6638609 in q_dbus_connection_dispatch (this=0x8cb870) at qdbus_symbols_p.h:115
#5 QDBusConnectionPrivate::doDispatch (this=0x8cb870) at qdbusintegrator.cpp:1125
#6 0x00007ffff663ad6d in QDBusConnectionPrivate::socketRead (this=0x8cb870, fd=<value optimized out>) at qdbusintegrator.cpp:1145
#7 0x00007ffff667b5f3 in QDBusConnectionPrivate::qt_metacall (this=0x8cb870, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>,
    _a=0x7fffffffd780) at .moc/release-shared/moc_qdbusconnection_p.cpp:99
#8 0x00007ffff6e1b5f8 in QMetaObject::activate (sender=0x8c8b40, m=<value optimized out>, local_signal_index=<value optimized out>,
    argv=0x7fffffffd780) at kernel/qobject.cpp:3287
#9 0x00007ffff6e62b7e in QSocketNotifier::activated (this=<value optimized out>, _t1=27) at .moc/release-shared/moc_qsocketnotifier.cpp:89
#10 0x00007ffff6e20f4b in QSocketNotifier::event (this=0x8c8b40, e=0x7fffffffddc0) at kernel/qsocketnotifier.cpp:317
#11 0x00007ffff72f49f4 in QApplicationPrivate::notify_helper (this=0x6c8310, receiver=0x8c8b40, e=0x7fffffffddc0)
    at kernel/qapplication.cpp:4462
#12 0x00007ffff72f93ba in QApplication::notify (this=<value optimized out>, receiver=0x8c8b40, e=0x7fffffffddc0)
    at kernel/qapplication.cpp:4341
#13 0x00007ffff6e0649c in QCoreApplication::notifyInternal (this=0x7fffffffe080, receiver=0x8c8b40, event=0x7fffffffddc0)
    at kernel/qcoreapplication.cpp:731
#14 0x00007ffff6e30da9 in sendEvent (source=0x6c8910) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#15 socketNotifierSourceDispatch (source=0x6c8910) at kernel/qeventdispatcher_glib.cpp:110
#16 0x00007ffff5d08bcd in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007ffff5d093a8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#18 0x00007ffff5d09639 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007ffff6e313ef in QEventDispatcherGlib::processEvents (this=0x615c10, flags=<value optimized out>)
    at kernel/qeventdispatcher_glib.cpp:422
#20 0x00007ffff739e4de in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>)
    at kernel/qguieventdispatcher_glib.cpp:204
#21 0x00007ffff6e05882 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#22 0x00007ffff6e05abc in QEventLoop::exec (this=0x7fffffffdff0, flags=...) at kernel/qeventloop.cpp:201
#23 0x00007ffff6e09ecb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#24 0x0000000000405ac2 in main ()

[Florian Boucault (fboucault)]

On my machine nothing happens when I set that dconf key. No crash, no change in the panel. I have the same version of unity 2d as you (on Natty).

[Albert Astals Cid (aacid)]

Olivier can you still repro this?

[Launchpad Janitor (janitor)]

[Expired for unity-2d (Ubuntu) because there has been no activity for 60 days.]