Pidgin segfaults Metacity using unity-2d in 12.04 due to liboverlay-scrollbar

Using pidgin 1:2.10.3-0ubuntu1 , overlay-scrollbar 0.2.16+r357-0ubuntu1 , Ubuntu 12.04 x86 32-bit...

I was reliably blowing up Metacity, if not Xorg itself, trying to launch Pidgin; see mess of a pidgin -d log below that hinted the problem might have something to do with scrollbars - and lo: setting LIBOVERLAY_SCROLLBAR=0 results in a working Pidgin.

Presumably this should be easy to reproduce. I would've been happy to just have had a startup script thrown in as a patch so as to not run into it. Under certain circumstances I may've managed to get it to take out more than just Metacity, like the entire X.org session, but I lost track of what exactly might reproduce that other than "trying repeatedly, because how the heck did a boring app like Pidgin manage to break?" It appears that was probably just an OOM kill for a crowded session with long uptime being stressed by whatever ridiculous thing X.org is being asked to do until it realizes it can't.

floid@miscreant:~$ pidgin -d
(22:44:06) prefs: Reading /home/floid/.purple/prefs.xml
(22:44:06) prefs: Finished reading /home/floid/.purple/prefs.xml
(22:44:06) prefs: purple_prefs_get_path: Unknown pref /pidgin/browsers/command
(22:44:06) dbus: okkk
(22:44:06) plugins: probing /usr/lib/pidgin/vvconfig.so
(22:44:06) plugins: probing /usr/lib/pidgin/markerline.so
(22:44:06) plugins: probing /usr/lib/pidgin/timestamp_format.so
(22:44:06) plugins: probing /usr/lib/pidgin/themeedit.so
(22:44:06) plugins: probing /usr/lib/pidgin/history.so
(22:44:06) plugins: probing /usr/lib/pidgin/convcolors.so
(22:44:06) plugins: probing /usr/lib/pidgin/extplacement.so
(22:44:06) plugins: probing /usr/lib/pidgin/gestures.so
(22:44:06) plugins: probing /usr/lib/pidgin/musicmessaging.so
(22:44:06) plugins: probing /usr/lib/pidgin/xmppdisco.so
(22:44:06) plugins: probing /usr/lib/pidgin/cap.so
(22:44:06) plugins: probing /usr/lib/pidgin/spellchk.so
(22:44:06) plugins: probing /usr/lib/pidgin/xmppconsole.so
(22:44:06) plugins: probing /usr/lib/pidgin/ticker.so
(22:44:06) plugins: probing /usr/lib/pidgin/notify.so
(22:44:06) plugins: probing /usr/lib/pidgin/gtkbuddynote.so
(22:44:06) plugins: probing /usr/lib/pidgin/timestamp.so
(22:44:06) plugins: probing /usr/lib/pidgin/pidginrc.so
(22:44:06) plugins: probing /usr/lib/pidgin/sendbutton.so
(22:44:06) plugins: probing /usr/lib/pidgin/iconaway.so
(22:44:06) plugins: probing /usr/lib/purple-2/libjabber.so
(22:44:06) plugins: /usr/lib/purple-2/libjabber.so is not usable because the 'purple_init_plugin' symbol could not be found. Does the plugin call the PURPLE_INIT_PLUGIN() macro?
(22:44:06) plugins: probing /usr/lib/purple-2/libnovell.so
(22:44:06) plugins: probing /usr/lib/purple-2/autoaccept.so
(22:44:06) plugins: probing /usr/lib/purple-2/libyahoojp.so
(22:44:06) plugins: probing /usr/lib/purple-2/libbonjour.so
(22:44:06) plugins: probing /usr/lib/purple-2/ssl-nss.so
(22:44:06) plugins: probing /usr/lib/purple-2/libzephyr.so
(22:44:06) plugins: probing /usr/lib/purple-2/libxmpp.so
(22:44:06) plugins: probing /usr/lib/purple-2/joinpart.so
(22:44:06) plugins: probing /usr/lib/purple-2/libirc.so
(22:44:06) plugins: probing /usr/lib/purple-2/libmxit.so
(22:44:06) prpl-loubserp-mxit: Loading MXit libPurple plugin...
(22:44:06) plugins: probing /usr/lib/purple-2/idle.so
(22:44:06) plugins: probing /usr/lib/purple-2/libgg.so
(22:44:06) plugins: probing /usr/lib/purple-2/perl.so
(22:44:06) plugins: probing /usr/lib/purple-2/buddynote.so
(22:44:06) plugins: probing /usr/lib/purple-2/libicq.so
(22:44:06) plugins: probing /usr/lib/purple-2/libsimple.so
(22:44:06) plugins: probing /usr/lib/purple-2/ssl.so
(22:44:06) plugins: probing /usr/lib/purple-2/pidgin-libnotify.so
(22:44:06) plugins: probing /usr/lib/purple-2/libymsg.so
(22:44:06) plugins: /usr/lib/purple-2/libymsg.so is not usable because the 'purple_init_plugin' symbol could not be found. Does the plugin call the PURPLE_INIT_PLUGIN() macro?
(22:44:06) plugins: probing /usr/lib/purple-2/tcl.so
(22:44:06) plugins: /usr/lib/purple-2/tcl.so is not loadable: libtk8.5.so.0: cannot open shared object file: No such file or directory
(22:44:06) plugins: probing /usr/lib/purple-2/log_reader.so
(22:44:06) plugins: probing /usr/lib/purple-2/libmyspace.so
(22:44:06) plugins: probing /usr/lib/purple-2/psychic.so
(22:44:06) plugins: probing /usr/lib/purple-2/liboscar.so
(22:44:06) plugins: /usr/lib/purple-2/liboscar.so is not usable because the 'purple_init_plugin' symbol could not be found. Does the plugin call the PURPLE_INIT_PLUGIN() macro?
(22:44:06) plugins: probing /usr/lib/purple-2/newline.so
(22:44:06) plugins: probing /usr/lib/purple-2/dbus-example.so
(22:44:06) plugins: probing /usr/lib/purple-2/libyahoo.so
(22:44:06) plugins: probing /usr/lib/purple-2/statenotify.so
(22:44:06) plugins: probing /usr/lib/purple-2/libsametime.so
(22:44:06) plugins: /usr/lib/purple-2/libsametime.so has a prefs_info, but is a prpl. This is no longer supported.
(22:44:06) plugins: probing /usr/lib/purple-2/offlinemsg.so
(22:44:06) plugins: probing /usr/lib/purple-2/libmsn.so
(22:44:06) plugins: probing /usr/lib/purple-2/libaim.so
(22:44:06) util: Reading file xmpp-caps.xml from directory /home/floid/.purple
(22:44:06) util: File /home/floid/.purple/xmpp-caps.xml does not exist (this is
not necessarily an error)
(22:44:06) jabber: creating hash tables for data objects
(22:44:06) prefs: /purple/status/scores/offline changed, scheduling save.
(22:44:06) prefs: /purple/status/scores/available changed, scheduling save.
(22:44:06) prefs: /purple/status/scores/invisible changed, scheduling save.
(22:44:06) prefs: /purple/status/scores/away changed, scheduling save.
(22:44:06) prefs: /purple/status/scores/extended_away changed, scheduling save.
(22:44:06) prefs: /purple/status/scores/idle changed, scheduling save.
(22:44:06) prefs: /purple/status/scores/offline_msg changed, scheduling save.
(22:44:06) util: Reading file accounts.xml from directory /home/floid/.purple
(22:44:06) util: File /home/floid/.purple/accounts.xml does not exist (this is not necessarily an error)
(22:44:06) util: Reading file status.xml from directory /home/floid/.purple
(22:44:06) certificate: CertificateVerifier x509, singleuse requested but not found.
(22:44:06) certificate: CertificateVerifier singleuse registered
(22:44:06) certificate: CertificatePool x509, ca requested but not found.
(22:44:06) certificate: CertificateScheme x509 requested but not found.
(22:44:06) certificate/x509/ca: Lazy init failed because an X.509 Scheme is not yet registered. Maybe it will be better later.
(22:44:06) certificate/x509/ca: Init failed, probably because a dependency is not yet registered. It has been deferred to later.
(22:44:06) certificate: CertificatePool ca registered
(22:44:06) certificate: CertificatePool x509, tls_peers requested but not found.
(22:44:06) certificate: CertificatePool tls_peers registered
(22:44:06) certificate: CertificateVerifier x509, tls_cached requested but not found.
(22:44:06) certificate: CertificateVerifier tls_cached registered
(22:44:06) prefs: /purple/logging/format changed, scheduling save.
(22:44:06) prefs: /purple/logging/format changed, scheduling save.
(22:44:06) prefs: /purple/proxy/type changed, scheduling save.
(22:44:06) prefs: /purple/proxy/host changed, scheduling save.
(22:44:06) prefs: /purple/proxy/port changed, scheduling save.
(22:44:06) prefs: /purple/proxy/username changed, scheduling save.
(22:44:06) prefs: /purple/proxy/password changed, scheduling save.
(22:44:06) certificate: CertificateScheme x509 requested but not found.
(22:44:06) certificate: CertificateScheme x509 registered
(22:44:06) util: Reading file smileys.xml from directory /home/floid/.purple
(22:44:06) util: File /home/floid/.purple/smileys.xml does not exist (this is not necessarily an error)
(22:44:06) stun: using server
(22:44:07) sound: Initializing sound output drivers.
(22:44:07) prefs: /pidgin/conversations/placement changed, scheduling save.
(22:44:07) prefs: purple_prefs_get_bool: Unknown pref /pidgin/docklet/x11/embedded
(22:44:08) gtkmedia: Registering media element types
(22:44:08) util: Reading file blist.xml from directory /home/floid/.purple
(22:44:08) util: File /home/floid/.purple/blist.xml does not exist (this is not necessarily an error)
(22:44:08) plugins: Loading saved plugin /usr/lib/purple-2/pidgin-libnotify.so
(22:44:08) plugins: Loading saved plugin /usr/lib/purple-2/ssl-nss.so
(22:44:08) plugins: Loading saved plugin /usr/lib/purple-2/ssl.so
(22:44:08) pounce: Error reading pounces: Failed to open file '/home/floid/.purple/pounces.xml': No such file or directory
(22:44:08) Session Management: ICE initialized.
(22:44:08) Session Management: Connecting with no previous ID
(22:44:08) Session Management: Handling new ICE connection...
(22:44:08) done.
(22:44:08) Session Management: Connected to manager (gnome-session) with client ID 10c3d4b442a92b6124135485184879850500000021370059
(22:44:08) Session Management: Using pidgin as command
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gdk: Native Windows wider or taller than 65535 pixels are not supported
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: _ubuntu_gtk_overlay_scrollbar_new: assertion `os_scrollbar_new' failed
(22:44:09) Gtk: IA__gtk_widget_set_composite_name: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_set_parent: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) GLib-GObject: g_object_ref: assertion `G_IS_OBJECT (object)' failed
(22:44:09) Gtk: IA__gtk_widget_show: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) GLib-GObject: invalid (NULL) pointer instance
(22:44:09) GLib-GObject: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(22:44:09) Gtk: gtk_scrolled_window_adjustment_changed: assertion `adjustment != NULL' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: IA__gtk_range_get_adjustment: assertion `GTK_IS_RANGE (range)' failed
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gdk: Native Windows wider or taller than 65535 pixels are not supported
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:09) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Session Management: Received first save_yourself
(22:44:10) Session Management: Received save_complete
(22:44:10) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_size_request: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
(22:44:10) Gtk: IA__gtk_widget_get_visible: assertion `GTK_IS_WIDGET (widget)' failed
The program 'Pidgin' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadAlloc (insufficient resources for operation)'.
  (Details: serial 532 error_code 11 request_code 53 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
floid@miscreant:~$ LIBOVERLAY_SCROLLBAR=0 pidgin

{Metacity restarted from console after segfaulting sometime concurrent with the BadAlloc; Pidgin now running happily.}