[Freeciv-Dev] Re: Client core (PR#1107)

[jdorje@xxxxxxxxxxxxxxxxxxxxx]

Paul Zastoupil wrote:

> I was trying to hit 't' on s city.
>
> civclient: map.c:1217: map_get_city: Assertion `is_normal_map_pos(((x)),((y)))' 
> failed.
>
> #0  0x403278d1 in __kill () from /lib/libc.so.6
> #1  0x4032764d in raise (sig=6) at ../sysdeps/posix/raise.c:27
> #2  0x40328cb8 in abort () at ../sysdeps/generic/abort.c:88
> #3  0x40320d71 in __assert_fail (assertion=0x80c3900 "is_normal_map_pos(((x)),((y)))", 
>     file=0x80c4564 "map.c", line=1217, function=0x80c475b "map_get_city") at assert.c:74
> #4  0x080a8521 in map_get_city (x=-1, y=30) at map.c:1217
> #5  0x0808c7a5 in find_city_near_tile (x=0, y=32) at mapctrl.c:361
> #6  0x0808cab0 in key_city_workers (widget=0x81a24a0, ev=0x8198688) at 
> mapctrl.c:461
> #7  0x08085a92 in keyboard_handler (widget=0x81a24a0, event=0x8198688) at 
> gui_main.c:303
> #8  0x400db841 in gtk_marshal_BOOL__POINTER (object=0x81a24a0, 
>     func=0x808545c <keyboard_handler>, func_data=0x0, args=0xbffff610) at gtkmarshal.c:28
> #9  0x4010b0be in gtk_handlers_run (handlers=0x81fd078, signal=0xbffff5b0, 
>     object=0x81a24a0, params=0xbffff610, after=0) at gtksignal.c:1917
> #10 0x4010a51f in gtk_signal_real_emit (object=0x81a24a0, signal_id=26, 
>     params=0xbffff610) at gtksignal.c:1477
> #11 0x40108594 in gtk_signal_emit (object=0x81a24a0, signal_id=26) at 
> gtksignal.c:552
> #12 0x4013f874 in gtk_widget_event (widget=0x81a24a0, event=0x8198688)
>     at gtkwidget.c:2864
> #13 0x400db73c in gtk_propagate_event (widget=0x81f99b8, event=0x8198688)
>     at gtkmain.c:1360
> #14 0x400da975 in gtk_main_do_event (event=0x8198688) at gtkmain.c:818
> #15 0x4018e10f in gdk_event_dispatch (source_data=0x0, current_time=0xbffff9e0, 
>     user_data=0x0) at gdkevents.c:2139
> #16 0x401bd055 in g_main_dispatch (dispatch_time=0xbffff9e0) at gmain.c:656
> #17 0x401bd659 in g_main_iterate (block=1, dispatch=1) at gmain.c:877
> #18 0x401bd7e8 in g_main_run (loop=0x8213b00) at gmain.c:935
> #19 0x400da27b in gtk_main () at gtkmain.c:524
> #20 0x0808728e in ui_main (argc=3, argv=0xbffffb24) at gui_main.c:836
> #21 0x0805f178 in main (argc=3, argv=0xbffffb24) at civclient.c:189
> #22 0x40315306 in __libc_start_main (main=0x805ed20 <main>, argc=3, ubp_av=0xbffffb24, 
>     init=0x805c680 <_init>, fini=0x80b9580 <_fini>, rtld_fini=0x4000d2cc <_dl_fini>, 
>     stack_end=0xbffffb1c) at ../sysdeps/generic/libc-start.c:129
When you click on a tile like that, the game tries to associate a city 
with it, so it calls find_city_near_tile.  Unfortunately, 
find_city_near_tile is not CHECK_MAP_POS-safe, so it'll fail the 
assertion any time a wrap-around is needed to find the city (i.e. any 
time you're working near x==0 or x==map.xsize-1).
This is easy enough to fix.  But, it's more complicated because each of 
gui-gtk, gui-xaw, and gui-mui uses its own local (static) version of the 
function; this code is not common.  However, nothing in the code is 
gui-specific, and in fact all three versions of the code are completely 
identical.  (I'm not sure what gui-win32 does for this...maybe it's not 
implemented yet.)
I therefore propose that this code be unified into find_city_near_tile() 
in mapctrl_common.[ch] in client/.  A patch for this will follow.
Attached is a preleminary patch for this that should fix the segfault if 
you're playing under GTK.  Please test if possible.
jason

? old
? topology
Index: client/gui-gtk/mapctrl.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk/mapctrl.c,v
retrieving revision 1.50
diff -u -r1.50 mapctrl.c
--- client/gui-gtk/mapctrl.c    2001/12/08 15:15:51     1.50
+++ client/gui-gtk/mapctrl.c    2001/12/09 03:18:10
@@ -358,7 +358,10 @@
 
   pcity2 = NULL;
   city_map_iterate(i, j)  {
-    pcity = map_get_city(x+i-2, y+j-2);
+    int map_x, map_y;
+    if (!base_city_map_to_map(&map_x, &map_y, x, y, i, j))
+      continue;
+    pcity = map_get_city(map_x, map_y);
     if(pcity && pcity->owner==game.player_idx && 
        get_worker_city(pcity,4-i,4-j)==C_TILE_EMPTY)  {  /* rule b */
       if(pcity==last_pcity) return pcity;  /* rule c */