Comment 1 for bug 303453

Confirmed on svn trunk. It seems to be some kind of infinite loop. I get this backtrace when I break:

(gdb) bt
#0 0xb8013430 in __kernel_vsyscall ()
#1 0xb6394c01 in select () from /lib/tls/i686/cmov/libc.so.6
#2 0xb6266e5f in ?? () from /usr/lib/libxcb.so.1
#3 0xb626756e in ?? () from /usr/lib/libxcb.so.1
#4 0xb6267afb in xcb_send_request () from /usr/lib/libxcb.so.1
#5 0xb6933166 in _XPutXCBBuffer () from /usr/lib/libX11.so.6
#6 0xb6933530 in ?? () from /usr/lib/libX11.so.6
#7 0xb69e658c in XRenderCompositeTrapezoids (dpy=0x8f29e00, op=12, src=79714139, dst=79728197, maskFormat=0x8f6af28, xSrc=0, ySrc=0,
    traps=0xbfd1075c, ntrap=0) at ../../src/Trap.c:71
#8 0xb6b5bc22 in _cairo_xlib_surface_composite_trapezoids (op=CAIRO_OPERATOR_ADD, pattern=0xbfd11074, abstract_dst=0x9662138,
    antialias=CAIRO_ANTIALIAS_GRAY, src_x=0, src_y=0, dst_x=0, dst_y=0, width=2, height=337, traps=0xbfd113d8, num_traps=1)
    at cairo-xlib-surface.c:2232
#9 0xb6b3b8f4 in _cairo_surface_composite_trapezoids (op=CAIRO_OPERATOR_ADD, pattern=0xbfd11074, dst=0x9662138,
    antialias=CAIRO_ANTIALIAS_GRAY, src_x=0, src_y=0, dst_x=0, dst_y=0, width=2, height=337, traps=0xbfd113d8, num_traps=1)
    at cairo-surface.c:1724
#10 0xb6b3da43 in _composite_traps_draw_func (closure=0xbfd11354, op=CAIRO_OPERATOR_ADD, src=0xbfd11074, dst=0x9662138, dst_x=0, dst_y=0,
    extents=0xbfd11344) at cairo-surface-fallback.c:501
#11 0xb6b3cf78 in _create_composite_mask_pattern (mask_pattern=0xbfd11190, clip=0x9661084, draw_func=0xb6b3d91f <_composite_traps_draw_func>,
    draw_closure=0xbfd11354, dst=0x9584b08, extents=0xbfd11344) at cairo-surface-fallback.c:130
#12 0xb6b3d02f in _clip_and_composite_with_mask (clip=0x9661084, op=CAIRO_OPERATOR_OVER, src=0x94b7090,
    draw_func=0xb6b3d91f <_composite_traps_draw_func>, draw_closure=0xbfd11354, dst=0x9584b08, extents=0xbfd11344)
    at cairo-surface-fallback.c:168
#13 0xb6b3d5bc in _clip_and_composite (clip=0x9661084, op=CAIRO_OPERATOR_OVER, src=0x94b7090,
    draw_func=0xb6b3d91f <_composite_traps_draw_func>, draw_closure=0xbfd11354, dst=0x9584b08, extents=0xbfd11344)
    at cairo-surface-fallback.c:383
#14 0xb6b3de53 in _clip_and_composite_trapezoids (src=0x94b7090, op=CAIRO_OPERATOR_OVER, dst=0x9584b08, traps=0xbfd113b8, clip=0x9661084,
    antialias=CAIRO_ANTIALIAS_GRAY) at cairo-surface-fallback.c:658
#15 0xb6b3e3a9 in _cairo_surface_fallback_stroke (surface=0x9584b08, op=CAIRO_OPERATOR_OVER, source=0x94b7090, path=0x96605d0,
    stroke_style=0x9661010, ctm=0xbfd114d0, ctm_inverse=0xbfd114a0, tolerance=0.10000000000000001, antialias=CAIRO_ANTIALIAS_GRAY)
    at cairo-surface-fallback.c:833
#16 0xb6b3b608 in _cairo_surface_stroke (surface=0x9584b08, op=CAIRO_OPERATOR_OVER, source=0xbfd1175c, path=0x96605d0,
    stroke_style=0x9661010, ctm=0x96610cc, ctm_inverse=0x96610fc, tolerance=0.10000000000000001, antialias=CAIRO_ANTIALIAS_GRAY)
    at cairo-surface.c:1641
#17 0xb6b1e030 in _cairo_gstate_stroke (gstate=0x9661000, path=0x96605d0) at cairo-gstate.c:928
#18 0xb6b17a7f in *INT_cairo_stroke_preserve (cr=0x9660448) at cairo.c:2115
#19 0xb6b17a47 in *INT_cairo_stroke (cr=0x9660448) at cairo.c:2088
#20 0xb7abeb35 in paint_vertical_lines (simple=0x9660388, cr=0x9660448, bounds=0xbfd11938) at goocanvasgrid.c:735
#21 0xb7abeea2 in goo_canvas_grid_paint (simple=0x9660388, cr=0x9660448, bounds=0xbfd11c20) at goocanvasgrid.c:838
#22 0xb7b39d7e in Goocanvas::ItemSimple_Class::simple_paint_vfunc_callback (self=0x9660388, cr=0x9660448, bounds=0xbfd11c20)
    at itemsimple.cc:215
#23 0xb7acb181 in goo_canvas_item_simple_paint (item=0x9660388, cr=0x9660448, bounds=0xbfd11c20, scale=0.57999999999999996)
    at goocanvasitemsimple.c:1360
---Type <return> to continue, or q <return> to quit---
#24 0xb7ac456d in goo_canvas_item_paint (item=0x9660388, cr=0x9660448, bounds=0xbfd11c20, scale=0.57999999999999996) at goocanvasitem.c:1646
#25 0xb7ac0699 in goo_canvas_group_paint (item=0x9577dc0, cr=0x9660448, bounds=0xbfd11c20, scale=0.57999999999999996) at goocanvasgroup.c:571
#26 0xb7ac456d in goo_canvas_item_paint (item=0x9577dc0, cr=0x9660448, bounds=0xbfd11c20, scale=0.57999999999999996) at goocanvasitem.c:1646
#27 0xb7ac0699 in goo_canvas_group_paint (item=0x9577d30, cr=0x9660448, bounds=0xbfd11c20, scale=0.57999999999999996) at goocanvasgroup.c:571
#28 0xb7ac456d in goo_canvas_item_paint (item=0x9577d30, cr=0x9660448, bounds=0xbfd11c20, scale=0.57999999999999996) at goocanvasitem.c:1646
#29 0xb7ae31bb in goo_canvas_expose_event (widget=0x8f6f940, event=0xbfd1225c) at goocanvas.c:2679
#30 0xb7959e9c in Gtk::Widget::on_expose_event (this=0x95dab7c, event=0xbfd1225c) at widget.cc:7981
#31 0xb7962ef0 in Gtk::Widget_Class::expose_event_callback (self=0x8f6f940, p0=0xbfd1225c) at widget.cc:4834
#32 0xb6efac94 in _gtk_marshal_BOOLEAN__BOXED (closure=0x8f33da0, return_value=0xbfd11efc, n_param_values=2, param_values=0x9660a00,
    invocation_hint=0xbfd11ee8, marshal_data=0xb7962e80) at gtkmarshalers.c:84
#33 0xb67889ed in g_type_class_meta_marshal (closure=0x8f33da0, return_value=0xbfd11efc, n_param_values=2, param_values=0x9660a00,
    invocation_hint=0xbfd11ee8, marshal_data=0xc8) at gclosure.c:878
#34 0xb67886d5 in IA__g_closure_invoke (closure=0x8f33da0, return_value=0xbfd11efc, n_param_values=2, param_values=0x9660a00,
    invocation_hint=0xbfd11ee8) at gclosure.c:767
#35 0xb67a1ab9 in signal_emit_unlocked_R (node=0x8f4ab90, detail=0, instance=0x8f6f940, emission_return=0xbfd12098,
    instance_and_params=0x9660a00) at gsignal.c:3282
#36 0xb67a0a49 in IA__g_signal_emit_valist (instance=0x8f6f940, signal_id=73, detail=0, var_args=0xbfd12160 "\200!ѿ\003") at gsignal.c:2987
#37 0xb67a0ce2 in IA__g_signal_emit (instance=0x8f6f940, signal_id=73, detail=0) at gsignal.c:3034
#38 0xb7071f14 in gtk_widget_event_internal (widget=0x8f6f940, event=0xbfd1225c) at gtkwidget.c:4744
#39 0xb7071b69 in IA__gtk_widget_send_expose (widget=0x8f6f940, event=0xbfd1225c) at gtkwidget.c:4573
#40 0xb6ef779c in IA__gtk_main_do_event (event=0xbfd1225c) at gtkmain.c:1553
#41 0xb6cba374 in gdk_window_process_updates_internal (window=0x9622188) at gdkwindow.c:2594
#42 0xb6cba4f9 in IA__gdk_window_process_all_updates () at gdkwindow.c:2660
#43 0xb6cba104 in gdk_window_update_idle (data=0x0) at gdkwindow.c:2504
#44 0xb6c969c9 in gdk_threads_dispatch (data=0x965f150) at gdk.c:474
#45 0xb66cc667 in g_idle_dispatch (source=0x95f6940, callback=0xb6c96973 <gdk_threads_dispatch>, user_data=0x965f150) at gmain.c:3924
#46 0xb66c873e in g_main_dispatch (context=0x8f3a188) at gmain.c:1814
#47 0xb66c9c16 in IA__g_main_context_dispatch (context=0x8f3a188) at gmain.c:2367
#48 0xb66ca16a in g_main_context_iterate (context=0x8f3a188, block=1, dispatch=1, self=0x8e83878) at gmain.c:2448
#49 0xb66ca941 in IA__g_main_loop_run (loop=0x902bcd0) at gmain.c:2656
#50 0xb6ef6f09 in IA__gtk_main () at gtkmain.c:1200
#51 0xb78da107 in Gtk::Main::run_impl (this=0xbfd125bc) at main.cc:536
#52 0xb78d9f02 in Gtk::Main::run () at main.cc:483
#53 0x0808e405 in main (argc=32, argv=0xbfd127c4) at main.cc:310