[Freeciv-Dev] (PR#4568) PF crash

["Jason Short" <jshort@xxxxxxxxxxxxxx>]

This crash in pathfinding occurred with a standard goto toward a ship.  I'm 
using the borders patch.

civclient: path_finding.c:303: pf_next: Assertion `cost >= 0' failed.

Loaded symbols for /lib/libnss_files.so.2
#0  0x4041afd1 in kill () from /lib/libc.so.6
(gdb) bt
#0  0x4041afd1 in kill () from /lib/libc.so.6
#1  0x4041ac94 in raise () from /lib/libc.so.6
#2  0x4041c04d in abort () from /lib/libc.so.6
#3  0x40414695 in __assert_fail () from /lib/libc.so.6
#4  0x080b7a0c in pf_next (pf_map=0x93a4590) at path_finding.c:249
#5  0x080b8208 in pf_get_path (pf_map=0x93a4590, x=13, y=27)
    at path_finding.c:625
#6  0x0806bfa8 in update_last_part (x=13, y=27) at goto.c:138
#7  0x0806c789 in draw_line (dest_x=13, dest_y=27) at goto.c:415
#8  0x0806b25f in do_unit_goto (x=13, y=27) at control.c:1379
#9  0x0806b003 in do_map_click (xtile=13, ytile=27) at control.c:1313
#10 0x0806fa09 in action_button_pressed (canvas_x=0, canvas_y=0)
    at mapctrl_common.c:86
#11 0x080a3b2f in butt_down_mapcanvas (w=0x82cd3e0, ev=0x82eb8d8)
    at mapctrl.c:337
#12 0x401b87d6 in gtk_marshal_BOOL__POINTER (object=0x0,
    func=0x80a3a10 <butt_down_mapcanvas>, func_data=0x0, args=0x0)
    at gtkmarshal.c:28
#13 0x401f09d5 in gtk_handlers_run (handlers=0x82c3b18, signal=0xbffff5a0,
    object=0x82cd3e0, params=0xbffff610, after=0) at gtksignal.c:1912
#14 0x401efb2d in gtk_signal_real_emit (object=0x82cd3e0, signal_id=20,
    params=0xbffff610) at gtksignal.c:1477
#15 0x401ed462 in gtk_signal_emit (object=0x82cd3e0, signal_id=20)
---Type <return> to continue, or q <return> to quit---
    at gtksignal.c:552
#16 0x4022ea38 in gtk_widget_event (widget=0x82cd3e0, event=0x82eb8d8)
    at gtkwidget.c:2864
#17 0x401b861f in gtk_propagate_event (widget=0x82eb8d8, event=0x82eb8d8)
    at gtkmain.c:1385
#18 0x401b73a4 in gtk_main_do_event (event=0x82eb8d8) at gtkmain.c:818
#19 0x40277be5 in gdk_event_dispatch (source_data=0x0,
    current_time=0xbffffa10, user_data=0x0) at gdkevents.c:2139
#20 0x402ab97e in g_main_dispatch () from /usr/lib/libglib-1.2.so.0
#21 0x402abe59 in g_main_iterate () from /usr/lib/libglib-1.2.so.0
#22 0x402ac0f4 in g_main_run () from /usr/lib/libglib-1.2.so.0
#23 0x401b6e2f in gtk_main () at gtkmain.c:524
#24 0x0809d0d3 in ui_main (argc=1, argv=0xbffffb74) at gui_main.c:958
#25 0x08064d70 in main (argc=1, argv=0xbffffb74) at civclient.c:239
#26 0x404094ed in __libc_start_main () from /lib/libc.so.6