[Freeciv-Dev] (PR#2593) AI segfault

["Jason Short via RT" <rt@xxxxxxxxxxxxxx>]

I ran an autogame with aifill 30, xsize 200, ysize 100.  The game
crashed in year -950.

#0  0x0809c592 in is_wonder (id=7804) at improvement.c:289
289       return (improvement_types[id].is_wonder);
(gdb) p game.year
$1 = -950
(gdb) bt
#0  0x0809c592 in is_wonder (id=7804) at improvement.c:289
#1  0x080c50d1 in ai_diplomat_city (punit=0x824dbe0, ctarget=0x81e3ee0)
    at aidiplomat.c:62
#2  0x080c07c8 in ai_manage_units (pplayer=0x8132620) at aiunit.c:2505
#3  0x0804f97d in main_loop () at srv_main.c:430
#4  0x0804e8b8 in srv_loop () at srv_main.c:2123
#5  0x0804e471 in srv_main () at srv_main.c:1910
#6  0x08049b12 in main (argc=1, argv=0xbffffb44) at civserver.c:154
#7  0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6

Savegame (from 1000 BC) available; the crash appears to be reproducable.

jason