[Freeciv-Dev] (PR#4757) server_crash: pending_seen is off

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

While playing a game with gen-topologies and PR#4683 patches:

civserver: maphand.c:450: decrement_pending_seen: Assertion 
`plr_tile->pending_seen != 0' failed.

#4  0x08080207 in decrement_pending_seen (pplayer=0x0, x=0, y=0)
     at maphand.c:452
#5  0x08080bc9 in fog_area (pplayer=0x81811b0, x=43, y=84, len=1)
     at maphand.c:597
#6  0x080632d4 in move_unit (punit=0x832c5a0, dest_x=42, dest_y=85,
     transport_units=true, take_from_land=true, move_cost=3) at 
unittools.c:2896
#7  0x0805a023 in handle_unit_move_request (punit=0x832c5a0, dest_x=42,
     dest_y=85, igzoc=false, move_diplomat_city=false) at unithand.c:1099
#8  0x08058eb5 in handle_move_unit (pplayer=0x0, pmove=0xbffff870)
     at unithand.c:661
#9  0x080d68f2 in ai_unit_move (punit=0x832c5a0, x=42, y=85) at 
aitools.c:358
#10 0x0807843d in do_unit_goto (punit=0x832c5a0, restriction=GOTO_MOVE_ANY,
     trigger_special_ability=false) at gotohand.c:1353
#11 0x080d5e00 in ai_unit_goto (punit=0x832c5a0, x=20, y=64) at 
aitools.c:128
#12 0x080d5c49 in ai_unit_gothere (punit=0x832c5a0) at aitools.c:99
#13 0x080ddd6c in ai_manage_ferryboat (pplayer=0x81811b0, punit=0x832c5a0)
     at aiunit.c:2664
#14 0x080dee5e in ai_manage_units (pplayer=0x81811b0) at aiunit.c:2898
#15 0x0804e4d9 in ai_start_turn () at srv_main.c:436
#16 0x0804fe17 in main_loop () at srv_main.c:1445
#17 0x080502f5 in srv_main () at srv_main.c:1591
#18 0x0804a008 in main (argc=135320704, argv=0xbffffad4) at civserver.c:154
#19 0x401a34ed in __libc_start_main () from /lib/libc.so.6

It should be noted that (0,0) is not a normal map position, and so would 
have triggered the assert in map_get_player_tile (DEBUG was enabled). 
So presumably the pplayer==NULL parameter is also not correct.

(gdb) p map.xsize
$7 = 80
(gdb) p map.ysize
$8 = 50
(gdb) p map.topology_id
$9 = 7

Not reproducable.

jason