Comment 2 for bug 294904

I'm also experiencing this, after changing to a new smiley theme and closing preferences, pidgin crashes (assert failed?).

$ dpkg -s pidgin
Package: pidgin
Status: install ok installed
Priority: optional
Section: net
Installed-Size: 1952
Maintainer: Ubuntu Core Developers <email address hidden>
Architecture: i386
Version: 1:2.5.2-0ubuntu1
Replaces: gaim (<< 1:2.0.0+beta6-3), pidgin-data (<< 1:2.4.0-1)
Depends: pidgin-data (>= 1:2.5.2), pidgin-data (<< 1:2.5.2-z), libatk1.0-0 (>= 1.20.0), libc6 (>= 2.4), libcairo2 (>= 1.2.4), libdbus-1-3 (>= 1.0.2), libdbus-glib-1-2 (>= 0.71), libfontconfig1 (>= 2.4.0), libfreetype6 (>= 2.3.5), libglib2.0-0 (>= 2.16.0), libgstreamer0.10-0 (>= 0.10.10), libgtk2.0-0 (>= 2.14.1), libgtkspell0 (>= 2.0.10), libice6 (>= 1:1.0.0), liblaunchpad-integration1 (>= 0.1.17), libpango1.0-0 (>= 1.21.6), libpurple0 (>= 1:2.5.2-0ubuntu1), libsm6, libstartup-notification0 (>= 0.8-1), libx11-6, libxss1, zlib1g (>= 1:1.1.4), gconf2 (>= 2.10.1-2), perl (>= 5.10.0-11.1ubuntu2), perlapi-5.10.0
Recommends: gstreamer0.10-plugins-base, gstreamer0.10-plugins-good
Suggests: gnome-panel (>= 2.1) | kicker (>= 3.1) | docker, evolution-data-server (>= 1.10.0), libsqlite3-0 (>= 3.5.9)
Conflicts: gaim (<< 1:2.0.0+beta6-3), pidgin-data (<< 1:2.4.0-1)
Description: graphical multi-protocol instant messaging client for X
....

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 8.10
Release: 8.10
Codename: intrepid

$ pidgin -d > pidgin_stdout.txt 2>pidgin_stderr.txt
*** glibc detected *** pidgin: free(): invalid pointer: 0x08934310 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0x41b673f4]
/lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0x41b69456]
/usr/lib/libcairo.so.2[0x421ac5cd]
/usr/lib/libcairo.so.2[0x421cd1b4]
/usr/lib/libcairo.so.2[0x421b1e66]
/usr/lib/libcairo.so.2[0x421b2115]
/usr/lib/libcairo.so.2[0x42199b38]
/usr/lib/libcairo.so.2(cairo_fill_preserve+0x2d)[0x421946fd]
/usr/lib/libcairo.so.2(cairo_fill+0x12)[0x42194722]
/usr/lib/libgdk-x11-2.0.so.0[0x4226ae1b]
/usr/lib/libgdk-x11-2.0.so.0(gdk_window_begin_paint_region+0x1bb)[0x4226d56b]
/usr/lib/libgtk-x11-2.0.so.0(gtk_main_do_event+0x51e)[0x423fe12e]
/usr/lib/libgdk-x11-2.0.so.0[0x4226d9b5]
/usr/lib/libgdk-x11-2.0.so.0(gdk_window_process_all_updates+0xff)[0x4226dfcf]
/usr/lib/libgdk-x11-2.0.so.0[0x4226dffb]
/usr/lib/libgdk-x11-2.0.so.0[0x4225146b]
/usr/lib/libglib-2.0.so.0[0xb7f3e7c1]
/usr/lib/libglib-2.0.so.0(g_main_context_dispatch+0x1e8)[0xb7f406f8]
/usr/lib/libglib-2.0.so.0[0xb7f43da3]
/usr/lib/libglib-2.0.so.0(g_main_loop_run+0x1d2)[0xb7f442c2]
/usr/lib/libgtk-x11-2.0.so.0(gtk_main+0xb9)[0x423fe3a9]
pidgin(main+0xc78)[0x80caaaf]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe5)[0x41b0e685]
pidgin[0x806d8b1]
======= Memory map: ========
08048000-0811d000 r-xp 00000000 fe:05 121369 /usr/bin/pidgin
0811d000-0811e000 r--p 000d4000 fe:05 121369 /usr/bin/pidgin
0811e000-0812f000 rw-p 000d5000 fe:05 121369 /usr/bin/pidgin
08738000-091e5000 rw-p 08738000 00:00 0 [heap]
41000000-4101a000 r-xp 00000000 fe:05 90534 /lib/ld-2.8.90.so
4101b000-4101c000 r--p 0001a000 fe:05 90534 /lib/ld-2.8.90.so
4101c000-4101d000 rw-p 0001b000 fe:05 90534 /lib/ld-2.8.90.so
41af8000-41c50000 r-xp 00000000 fe:05 99784 /lib/tls/i686/cmov/libc-2.8.90.so
41c50000-41c52000 r--p 00158000 fe:05 99784 /lib/tls/i686/cmov/libc-2.8.90.so
41c52000-41c53000 rw-p 0015a000 fe:05 99784 /lib/tls/i686/cmov/libc-2.8.90.so
41c53000-41c56000 rw-p 41c53000 00:00 0
41c58000-41c5a000 r-xp 00000000 fe:05 105293 /lib/tls/i686/cmov/libdl-2.8.90.so
41c5a000-41c5b000 r--p 00001000 fe:05 105293 /lib/tls/i686/cmov/libdl-2.8.90.so
41c5b000-41c5c000 rw-p 00002000 fe:05 105293 /lib/tls/i686/cmov/libdl-2.8.90.so
41c5e000-41c82000 r-xp 00000000 fe:05 120519 /lib/tls/i686/cmov/libm-2.8.90.so
41c82000-41c83000 r--p 00023000 fe:05 120519 /lib/tls/i686/cmov/libm-2.8.90.so
41c83000-41c84000 rw-p 00024000 fe:05 120519 /lib/tls/i686/cmov/libm-2.8.90.so
41c86000-41c9b000 r-xp 00000000 fe:05 105989 /lib/tls/i686/cmov/libpthread-2.8.90.so
41c9b000-41c9c000 r--p 00014000 fe:05 105989 /lib/tls/i686/cmov/libpthread-2.8.90.so
41c9c000-41c9d000 rw-p 00015000 fe:05 105989 /lib/tls/i686/cmov/libpthread-2.8.90.so
41c9d000-41c9f000 rw-p 41c9d000 00:00 0
41ca1000-41cc9000 r-xp 00000000 fe:05 43312 /lib/libpcre.so.3.12.1
41cc9000-41cca000 r--p 00027000 fe:05 43312 /lib/libpcre.so.3.12.1
41cca000-41ccb000 rw-p 00028000 fe:05 43312 /lib/libpcre.so.3.12.1
41d86000-41d8a000 r-xp 00000000 fe:05 120842 /usr/lib/libXdmcp.so.6.0.0
41d8a000-41d8b000 rw-p 00003000 fe:05 120842 /usr/lib/libXdmcp.so.6.0.0
41d8d000-41d8f000 r-xp 00000000 fe:05 120833 /usr/lib/libXau.so.6.0.0
41d8f000-41d90000 rw-p 00001000 fe:05 120833 /usr/lib/libXau.so.6.0.0
41d92000-41e7d000 r-xp 00000000 fe:05 121069 /usr/lib/libX11.so.6.2.0
41e7d000-41e7e000 r--p 000ea000 fe:05 121069 /usr/lib/libX11.so.6.2.0
41e7e000-41e80000 rw-p 000eb000 fe:05 121069 /usr/lib/libX11.so.6.2.0
41e80000-41e81000 rw-p 41e80000 00:00 0
41e83000-41e9a000 r-xp 00000000 fe:05 120847 /usr/lib/libxcb.so.1.0.0
41e9a000-41e9b000 r--p 00016000 fe:05 120847 /usr/lib/libxcb.so.1.0.0
41e9b000-41e9c000 rw-p 00017000 fe:05 120847 /usr/lib/libxcb.so.1.0.0
41e9e000-41e9f000 r-xp 00000000 fe:05 121065 /usr/lib/libxcb-xlib.so.0.0.0
41e9f000-41ea0000 r--p 00000000 fe:05 121065 /usr/lib/libxcb-xlib.so.0.0.0
41ea0000-41ea1000 rw-p 00001000 fe:05 121065 Aborted (core dumped)

Last messages from stdout:

(14:37:51) prefs: /pidgin/smileys/theme changed, scheduling save.
(14:37:52) GLib: g_nullify_pointer: assertion `nullify_location != NULL' failed
(14:37:52) GLib: g_nullify_pointer: assertion `nullify_location != NULL' failed
(14:37:52) GLib: g_nullify_pointer: assertion `nullify_location != NULL' failed
(14:37:52) GLib: g_nullify_pointer: assertion `nullify_location != NULL' failed
(14:37:52) Gtk: gtk_widget_has_screen: assertion `GTK_IS_WIDGET (widget)' failed
(14:37:52) Gtk: gtk_widget_has_screen: assertion `GTK_IS_WIDGET (widget)' failed
(14:37:52) Gtk: gtk_widget_has_screen: assertion `GTK_IS_WIDGET (widget)' failed
(14:37:52) Gtk: gtk_widget_has_screen: assertion `GTK_IS_WIDGET (widget)' failed
(14:37:52) Gtk: gtk_widget_has_screen: assertion `GTK_IS_WIDGET (widget)' failed
(14:37:52) GLib-GObject: instance with invalid (NULL) class pointer
(14:37:52) GLib-GObject: g_signal_emit_valist: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed