using the 'cursor' font causes pango ellipsising code to crash wnck-applet

Steps to reproduce the crash:
1. Use the gnome font manager to change the Application Font to 'Cursor'
2. Watch wnck-applet die

Stacktrace:

(gdb) bt
#0 0xb739b143 in raise () from /lib/tls/libc.so.6
#1 0xb739c739 in abort () from /lib/tls/libc.so.6
#2 0xb74c66a1 in g_logv () from /usr/lib/libglib-2.0.so.0
#3 0xb74c66d4 in g_log () from /usr/lib/libglib-2.0.so.0
#4 0xb74c6731 in g_assert_warning () from /usr/lib/libglib-2.0.so.0
#5 0xb79229f4 in pango_shape (text=0xb7924987 "...", length=3,
    analysis=0x81da20c, glyphs=0x818c3b0) at shape.c:75
#6 0xb7904b76 in shape_ellipsis (state=0xbfffcc00) at ellipsize.c:371
#7 0xb7904d58 in update_ellipsis_shape (state=0xbfffcc00) at ellipsize.c:465
#8 0xb7905040 in find_initial_span (state=0xbfffcc00) at ellipsize.c:554
#9 0xb7905639 in _pango_layout_line_ellipsize (line=0x810dac8,
    attrs=0x8085d28) at ellipsize.c:736
#10 0xb79191d9 in pango_layout_line_postprocess (line=0x810dac8,
    state=0xbfffcd40) at pango-layout.c:4221
#11 0xb7916da5 in process_line (layout=0x8185af0, state=0xbfffcd40)
    at pango-layout.c:3009
#12 0xb7917509 in pango_layout_check_lines (layout=0x8185af0)
    at pango-layout.c:3258
#13 0xb79152bf in pango_layout_get_extents_internal (layout=0x8185af0,
    ink_rect=0x0, logical_rect=0xbfffcf64, line_extents=0x0)
    at pango-layout.c:2005
#14 0xb7915776 in pango_layout_get_extents (layout=0x8185af0, ink_rect=0x0,
    logical_rect=0xbfffcf64) at pango-layout.c:2170
---Type <return> to continue, or q <return> to quit---
#15 0xb7b0acf7 in gtk_label_get_use_underline ()
   from /usr/lib/libgtk-x11-2.0.so.0
#16 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#17 0xb7577524 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#18 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#19 0xb757be23 in g_signal_emit_by_name () from /usr/lib/libgobject-2.0.so.0
#20 0xb7b5fec2 in gtk_size_group_remove_widget ()
   from /usr/lib/libgtk-x11-2.0.so.0
#21 0xb7b601c1 in _gtk_size_group_compute_requisition ()
   from /usr/lib/libgtk-x11-2.0.so.0
#22 0xb7bf56ac in gtk_widget_size_request () from /usr/lib/libgtk-x11-2.0.so.0
#23 0xb7ae4467 in gtk_hbox_new () from /usr/lib/libgtk-x11-2.0.so.0
#24 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#25 0xb7577524 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#26 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#27 0xb757be23 in g_signal_emit_by_name () from /usr/lib/libgobject-2.0.so.0
#28 0xb7b5fec2 in gtk_size_group_remove_widget ()
   from /usr/lib/libgtk-x11-2.0.so.0
#29 0xb7b601c1 in _gtk_size_group_compute_requisition ()
   from /usr/lib/libgtk-x11-2.0.so.0
#30 0xb7bf56ac in gtk_widget_size_request () from /usr/lib/libgtk-x11-2.0.so.0
#31 0xb7a60288 in gtk_button_set_relief () from /usr/lib/libgtk-x11-2.0.so.0
#32 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#33 0xb7577524 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#34 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#35 0xb757be23 in g_signal_emit_by_name () from /usr/lib/libgobject-2.0.so.0
#36 0xb7b5fec2 in gtk_size_group_remove_widget ()
   from /usr/lib/libgtk-x11-2.0.so.0
#37 0xb7b601c1 in _gtk_size_group_compute_requisition ()
   from /usr/lib/libgtk-x11-2.0.so.0
#38 0xb7bf56ac in gtk_widget_size_request () from /usr/lib/libgtk-x11-2.0.so.0
#39 0xb7fb66da in wnck_tasklist_set_icon_loader ()
   from /usr/lib/libwnck-1.so.16
#40 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#41 0xb7577524 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#42 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#43 0xb757be23 in g_signal_emit_by_name () from /usr/lib/libgobject-2.0.so.0
#44 0xb7b5fec2 in gtk_size_group_remove_widget ()
   from /usr/lib/libgtk-x11-2.0.so.0
#45 0xb7b601c1 in _gtk_size_group_compute_requisition ()
   from /usr/lib/libgtk-x11-2.0.so.0
#46 0xb7bf56ac in gtk_widget_size_request () from /usr/lib/libgtk-x11-2.0.so.0
#47 0xb7aba3af in gtk_event_box_set_above_child ()
   from /usr/lib/libgtk-x11-2.0.so.0
#48 0xb7fd1d8c in _panel_applet_popup_menu ()
   from /usr/lib/libpanel-applet-2.so.0
---Type <return> to continue, or q <return> to quit---
#49 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#50 0xb7577524 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#51 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#52 0xb757be23 in g_signal_emit_by_name () from /usr/lib/libgobject-2.0.so.0
#53 0xb7b5fec2 in gtk_size_group_remove_widget ()
   from /usr/lib/libgtk-x11-2.0.so.0
#54 0xb7b601c1 in _gtk_size_group_compute_requisition ()
   from /usr/lib/libgtk-x11-2.0.so.0
#55 0xb7bf56ac in gtk_widget_size_request () from /usr/lib/libgtk-x11-2.0.so.0
#56 0xb7c05278 in gtk_window_reshow_with_initial_size ()
   from /usr/lib/libgtk-x11-2.0.so.0
#57 0xb7e7b258 in bonobo_plug_set_control () from /usr/lib/libbonoboui-2.so.0
#58 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#59 0xb7577524 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#60 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#61 0xb757be23 in g_signal_emit_by_name () from /usr/lib/libgobject-2.0.so.0
#62 0xb7b5fec2 in gtk_size_group_remove_widget ()
   from /usr/lib/libgtk-x11-2.0.so.0
#63 0xb7b601c1 in _gtk_size_group_compute_requisition ()
   from /usr/lib/libgtk-x11-2.0.so.0
#64 0xb7bf56ac in gtk_widget_size_request () from /usr/lib/libgtk-x11-2.0.so.0
#65 0xb7c0636f in _gtk_window_constrain_size ()
   from /usr/lib/libgtk-x11-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#66 0xb7c06c3c in gtk_window_get_position () from /usr/lib/libgtk-x11-2.0.so.0
#67 0xb7c0d41d in gtk_plug_get_id () from /usr/lib/libgtk-x11-2.0.so.0
#68 0xb7569fae in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#69 0xb75778b1 in g_signal_init () from /usr/lib/libgobject-2.0.so.0
#70 0xb7578d6d in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#71 0xb75790a6 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#72 0xb7a96e43 in gtk_container_check_resize ()
   from /usr/lib/libgtk-x11-2.0.so.0
#73 0xb7a96eb6 in gtk_container_check_resize ()
   from /usr/lib/libgtk-x11-2.0.so.0
#74 0xb74be4f3 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#75 0xb74c0f0d in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#76 0xb74c119e in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#77 0xb765a6f3 in bonobo_main () from /usr/lib/libbonobo-2.so.0
#78 0xb7658ba9 in bonobo_generic_factory_main_timeout ()
   from /usr/lib/libbonobo-2.so.0
#79 0xb7658ac9 in bonobo_generic_factory_main () from /usr/lib/libbonobo-2.so.0
#80 0xb7fd42b2 in panel_applet_factory_main_closure ()
   from /usr/lib/libpanel-applet-2.so.0
#81 0xb7fd435a in panel_applet_factory_main ()
   from /usr/lib/libpanel-applet-2.so.0
#82 0x0804c9c4 in main ()
(gdb)

http://bugzilla.gnome.org/show_bug.cgi?id=304039: http://bugzilla.gnome.org/show_bug.cgi?id=304039