[Freeciv-Dev] CMA bug in cvs (PR#2108)

["Per I. Mathisen" <per@xxxxxxxxxxx>]

This happens sometimes when I build my first city. Try keep the same
civclient up and connect to several servers, build first city. Eventually
I get this core.

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1024 (LWP 21948)]
0x4043196d in memset () from /lib/libc.so.6
(gdb) bt
#0  0x4043196d in memset () from /lib/libc.so.6
#1  0x080f9a6e in ensure_invalid_cache2 (pcity=0x837d570,
total_tile_trade=6)
    at cma_core.c:1471
#2  0x080f9f58 in build_cache3 (pcity=0x837d570) at cma_core.c:1551
#3  0x080fa2d6 in optimize_final (pcity=0x837d570, parameter=0xbffff620,
    best_result=0xbffff65c) at cma_core.c:1659
#4  0x080faeb7 in cma_query_result (pcity=0x837d570, parameter=0xbffff620,
    result=0xbffff65c) at cma_core.c:1934
#5  0x08095105 in refresh_cma_dialog (pcity=0x837d570,
refresh=REFRESH_ALL)
    at cma_fe.c:330
#6  0x080846b2 in refresh_city_dialog (pcity=0x837d570) at citydlg.c:403
#7  0x080890ce in create_city_dialog (pcity=0x837d570, make_modal=0)
    at citydlg.c:1570
#8  0x08084854 in popup_city_dialog (pcity=0x837d570, make_modal=0)
    at citydlg.c:448
#9  0x080747e8 in handle_city_packet_common (pcity=0x837d570, is_new=1,
    popup=1, investigate=0) at packhand.c:495
#10 0x080745e1 in handle_city_info (packet=0x83f8dc0) at packhand.c:450
#11 0x08064720 in handle_packet_input (packet=0x83f8dc0, type=17)
    at civclient.c:297
#12 0x08068f53 in input_from_server (fd=18) at clinet.c:325
#13 0x080a6a92 in get_net_input (data=0x0, fid=18,
condition=GDK_INPUT_READ)
    at gui_main.c:1063
#14 0x401980de in gdk_get_show_events () from /usr/lib/libgdk-1.2.so.0
#15 0x401c7c40 in g_io_add_watch () from /usr/lib/libglib-1.2.so.0
#16 0x401c9309 in g_get_current_time () from /usr/lib/libglib-1.2.so.0
#17 0x401c9913 in g_get_current_time () from /usr/lib/libglib-1.2.so.0
#18 0x401c9aac in g_main_run () from /usr/lib/libglib-1.2.so.0
#19 0x400dde37 in gtk_main () from /usr/lib/libgtk-1.2.so.0
#20 0x080a652b in ui_main (argc=1, argv=0xbffffab4) at gui_main.c:897
#21 0x080645c7 in main (argc=1, argv=0xbffffab4) at civclient.c:226

 - Per