hexchat ubuntu part channel crash

(gdb) bt
#0  __GI___libc_free (mem=0x21) at malloc.c:2929
#1  0x000000000047a37a in free_user (user=0x1ebeb90, data=<optimised out>)
    at userlist.c:177
#2  0x000000000047956f in tree_foreach (t=0x21, func=0x0,
    func@entry=0x47a36d <free_user>, data=0x1fadb60, data@entry=0x0)
    at tree.c:209
#3  0x000000000047a3ed in userlist_free (sess=sess@entry=0x1eaf100)
    at userlist.c:189
#4  0x000000000045f962 in session_free (killsess=killsess@entry=0x1eaf100)
    at hexchat.c:633
#5  0x0000000000435e1f in mg_ircdestroy (sess=sess@entry=0x1eaf100)
    at maingui.c:1034
#6  0x000000000043a276 in mg_tab_close (sess=0x1eaf100) at maingui.c:1095
#7  0x000000000042a18e in fe_close_window (sess=<optimised out>)
    at fe-gtk.c:596
#8  0x000000000043afa7 in mg_close_sess (sess=sess@entry=0x1eaf100)
    at maingui.c:1305
#9  0x000000000043afbc in mg_xbutton_cb (cv=<optimised out>,
    ch=ch@entry=0x1e6dc00, tag=<optimised out>,
    userdata=userdata@entry=0x1eaf100) at maingui.c:1355
#10 0x000000000043b094 in mg_destroy_tab_cb (item=<optimised out>,
    ch=0x1e6dc00) at maingui.c:1403
#11 0x00007ffff5c16245 in g_closure_invoke ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007ffff5c27f3c in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00007ffff5c30748 in g_signal_emit_valist ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007ffff5c309af in g_signal_emit ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#15 0x00007ffff79d5086 in gtk_widget_activate ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#16 0x00007ffff78d0c2d in gtk_menu_shell_activate_item ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#17 0x00007ffff78d0fcb in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#18 0x00007ffff78bec0f in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#19 0x00007ffff5c16245 in g_closure_invoke ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#20 0x00007ffff5c27e32 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#21 0x00007ffff5c30255 in g_signal_emit_valist ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#22 0x00007ffff5c309af in g_signal_emit ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#23 0x00007ffff79d62fc in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#24 0x00007ffff78bd354 in gtk_propagate_event ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#25 0x00007ffff78bd7eb in gtk_main_do_event ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#26 0x00007ffff753176c in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgdk-x11-2.0.so.0
#27 0x00007ffff5940c5d in g_main_context_dispatch ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#28 0x00007ffff5940f48 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007ffff5941272 in g_main_loop_run ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007ffff78bc747 in gtk_main ()
   from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#31 0x0000000000429b6d in fe_main () at fe-gtk.c:320
#32 0x00000000004604b7 in main (argc=<optimised out>, argv=<optimised out>)
    at hexchat.c:1102

Here is the crash when using /timer -repeat 20 300 cycle #ubuntu

(gdb) bt
#0  __GI___libc_free (mem=0x31) at malloc.c:2929
#1  0x000000000047a37a in free_user (user=0x2113de0, data=<optimised out>) at userlist.c:177
#2  0x000000000047956f in tree_foreach (t=0x31, func=0x0, func@entry=0x47a36d <free_user>, data=0x1f26230, data@entry=0x0)
    at tree.c:209
#3  0x000000000047a3ed in userlist_free (sess=sess@entry=0x1927600) at userlist.c:189
#4  0x000000000047a452 in userlist_clear (sess=sess@entry=0x1927600) at userlist.c:207
#5  0x00000000004616b3 in clear_channel (sess=sess@entry=0x1927600) at inbound.c:76
#6  0x00000000004625bf in inbound_upart (serv=serv@entry=0x865610, chan=chan@entry=0x1f155e9 "#ubuntu",
    ip=ip@entry=0x7fffffffc440 "~snadge@unaffiliated/snadge", reason=reason@entry=0x491340 "",
    tags_data=tags_data@entry=0x7fffffffc110) at inbound.c:670
#7  0x0000000000480b20 in process_named_msg (tags_data=0x7fffffffc110, word_eol=0x7fffffffc2f0, word=0x7fffffffc1e0,
    type=<optimised out>, sess=0x1927600) at proto-irc.c:1108
#8  irc_inline (serv=<optimised out>, buf=<optimised out>, len=<optimised out>) at proto-irc.c:1562
#9  0x00000000004724c7 in server_inline (len=48, line=0x86592a ":snadge!~snadge@unaffiliated/snadge PART #ubuntu", serv=0x865610)
    at server.c:404
#10 server_read (source=<optimised out>, condition=<optimised out>, serv=0x865610) at server.c:468
#11 0x00007ffff5940b6d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#12 0x00007ffff5940f48 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#13 0x00007ffff5941272 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007ffff78bc747 in gtk_main () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#15 0x0000000000429b6d in fe_main () at fe-gtk.c:320
#16 0x00000000004604b7 in main (argc=<optimised out>, argv=<optimised out>) at hexchat.c:1102