(gdb) bt
#0  0x00007f70a55d0037 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00007f70a55d3698 in __GI_abort () at abort.c:90
#2  0x00000000004a56ad in sighandler (sig=11) at gtkmain.c:153
#3  <signal handler called>
#4  0x00000000029ab3d0 in ?? ()
#5  0x00007f70a5efc778 in purple_circular_buffer_mark_read (buffer=0x3868ad0, len=320) at circularbuffer.c:376
#6  0x00007f70922883cb in send_cb (data=0x3b847b0, source=-1, cond=(unknown: 0)) at flap_connection.c:1061
#7  0x00007f70922884a1 in flap_connection_send_byte_stream (bs=0x7fffd02c65d0, conn=0x3b847b0, count=320)
    at flap_connection.c:1086
#8  0x00007f70922885e9 in sendframe_flap (conn=0x3b847b0, frame=0x2796230) at flap_connection.c:1117
#9  0x00007f7092288646 in flap_connection_send (conn=0x3b847b0, frame=0x2796230) at flap_connection.c:1126
#10 0x00007f70922869ca in flap_connection_send_version_with_cookie_and_clientinfo (od=0x27d1400, conn=0x3b847b0,
    length=256,
    chipsahoy=0x3b94bf0 "long_binary_string", ci=0x7fffd02c66b0, allow_multiple_logins=1)
    at flap_connection.c:103
#11 0x00007f709228be9a in connection_common_established_cb (conn=0x3b847b0) at oscar.c:350

(gdb) frame 5
#5  0x00007f70a5efc778 in purple_circular_buffer_mark_read (buffer=0x3868ad0, len=320) at circularbuffer.c:376
376			return klass->mark_read(buffer, len);

(gdb) print klass
$1 = (PurpleCircularBufferClass *) 0x3868ad0

(gdb) print *klass
$2 = {parent = {g_type_class = {g_type = 62474896}, construct_properties = 0x1, constructor = 0x0, set_property = 0x0,
    get_property = 0x3b954a0, dispose = 0x100, finalize = 0x200, dispatch_properties_changed = 0x140,
    notify = 0x3b955e0, constructed = 0x3b954a0, flags = 43693008, pdummy = {0x1, 0x0, 0x400000000, 0x1600000008,
      0x5800000016, 0x3baae40}}, grow = 0x7f70a6ff2980, append = 0x0, max_read_size = 0x1, mark_read = 0x29ab3d0,
  purple_reserved1 = 0x2, purple_reserved2 = 0x0, purple_reserved3 = 0x400000000, purple_reserved4 = 0x2000000008}