[Freeciv-Dev] Re: (PR#3518) Can't popup city (cma bug?)

["Raimar Falke" <rf13@xxxxxxxxxxxxxxxxx>]

On Mon, Feb 24, 2003 at 10:43:06PM -0800, mateusz stefek wrote:
> 
> It's a bug in current cvs.
> Load walbrzych_bug.gz, login as mateusz.
> Every time you try to open Walbrzych the client crashes with message:
> civclient: cm.c:559: update_cache2: Assertion `p->production == 
> result->production[LUXURY] && p->surplus == result->surplus[LUXURY]' 
> failed.
> Aborted (core dumped)

The savegame shows two problems:
 - the asserts are off by one this leads to access of memory which
 isn't initialized and so produces the above core dump
 - the total trade (tile trade + trade routes) is estimated too low
 because for the trade route estimation cm.c doesn't use the maximal
 estimated tile trade.

I'm pretty sure that these were also the reasons for 2731.

A patch for these two problem is attached. 

        Raimar

-- 
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Index: common/aicore/cm.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/aicore/cm.c,v
retrieving revision 1.4
diff -u -u -r1.4 cm.c
--- common/aicore/cm.c  2003/02/04 17:07:44     1.4
+++ common/aicore/cm.c  2003/02/26 18:26:53
@@ -482,11 +482,11 @@
   freelog(LOG_DEBUG, "second: trade=%d spec=%d type=%d", trade, specialists,
          specialist_type);
 
-  assert(trade <= cache2.allocated_trade);
-  assert(specialists <= cache2.allocated_size);
+  assert(trade >= 0 && trade < cache2.allocated_trade);
+  assert(specialists >= 0 && specialists < cache2.allocated_size);
 
   return &cache2.secondary_stats[NUM_SPECIALISTS_ROLES *
-                                (cache2.allocated_size * (trade) +
+                                (cache2.allocated_size * trade +
                                  specialists) + specialist_type];
 }
 
@@ -497,8 +497,8 @@
 {
   freelog(LOG_DEBUG, "status: lux=%d worker=%d", luxury, workers);
 
-  assert(luxury <= cache2.allocated_luxury);
-  assert(workers <= cache2.allocated_size);
+  assert(luxury >=0 && luxury < cache2.allocated_luxury);
+  assert(workers >= 0 && workers < cache2.allocated_size);
 
   return &cache2.city_status[cache2.allocated_size * luxury + workers];
 }
@@ -1052,13 +1052,17 @@
 static void ensure_invalid_cache2(struct city *pcity, int total_tile_trade)
 {
   bool change_size = FALSE;
-  int i, luxury, total_trade = total_tile_trade;
+  int backup,i, luxury, total_trade = total_tile_trade;
 
+  /* Hack since trade_between_cities accesses pcity->tile_trade */
+  backup = pcity->tile_trade;
+  pcity->tile_trade = total_tile_trade;
   for (i = 0; i < NUM_TRADEROUTES; i++) {
     struct city *pc2 = find_city_by_id(pcity->trade[i]);
 
     total_trade += trade_between_cities(pcity, pc2);
   }
+  pcity->tile_trade = backup;
 
   /*
    * Estimate an upper limit for the luxury. We assume that the player