diff -urNX freeciv/diff_ignore freeciv/ai/advdiplomacy.c freeciv-dipl/ai/advdiplomacy.c
--- freeciv/ai/advdiplomacy.c	1970-01-01 01:00:00.000000000 +0100
+++ freeciv-dipl/ai/advdiplomacy.c	2002-11-02 00:50:29.000000000 +0100
@@ -0,0 +1,658 @@
+/********************************************************************** 
+ Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+***********************************************************************/
+
+#include "city.h"
+#include "tech.h"
+#include "diptreaty.h"
+#include "player.h"
+#include "game.h"
+#include "support.h"
+#include "shared.h"
+#include "packets.h"
+#include "rand.h"
+#include "log.h"
+#include "events.h"
+#include "mem.h"
+
+#include "diplhand.h"
+#include "spaceship.h"
+#include "plrhand.h"
+#include "citytools.h"
+
+#include "aidata.h"
+#include "aitools.h"
+#include "advmilitary.h"
+
+#include "advdiplomacy.h"
+
+#define LOG_DIPL LOG_NORMAL
+
+/* Prototypes */
+static int ai_goldequiv_city(struct city *pcity);
+static int ai_goldequiv_tech(struct player *pplayer, Tech_Type_id tech);
+static int ai_war_desire(struct player *pplayer, struct player *aplayer,
+                         struct ai_data *ai);
+static int ai_war_fear(struct player *pplayer, struct player *aplayer,
+                         struct ai_data *ai);
+static bool ai_attitude(struct ai_data *at, enum diplomacy_type dtype);
+static int ai_goldequiv_clause(struct player *pplayer, struct player *aplayer, 
+                               struct Clause *pclause, struct ai_data *ai);
+
+/* PATCH TODO LIST:
+	-> stdinhand.c, add game.diplomacy set option
+	-> advmilitary.c, fix diplomat tech want excess
+	-> ai_suggest_clauses(...), if balance is not ok?
+	-> make embassies work if one side has it for diplomacy?
+	-> allow AIs to cheat an embassy on meet in beginning?
+*/
+
+/********************************************************************** 
+NOTES ON THIS AI DIPLOMACY FILE:
+ -> Be very careful with infinities - they can lead to overflows.
+ -> Everything is measured in gold, even treaties. However, treaties
+    are meant to be broken, if that is measured profitable.
+ -> Some players can be give attitudes (see aidata.h). These can
+    severely impair an ai's ability to pursue a diplomacy to its
+    own gain, but it is very good for modpacks and easy difficulties.
+ -> We rely on omniscience here. Really.
+***********************************************************************/
+
+/********************************************************************** 
+  Send a diplomatic message. Use this instead of notify because we
+  may want to highligh/present these messages differently in the
+  future.
+
+  TODO: Replace E_DIPLOMATIC_INCIDENT with a new type.
+  TODO: Rewrite ...
+***********************************************************************/
+#define diplo_notify(pplayer, text, ...) \
+  notify_player_ex(pplayer, -1, -1, E_DIPLOMATIC_INCIDENT, text, __VA_ARGS__);
+
+/********************************************************************** 
+  Diplomat production is in advmilitary.c, we will add Marco Polo's
+  here later.
+***********************************************************************/
+void diplomacy_advisor_choose_tech(struct player *pplayer, 
+				  struct ai_choice *choice)
+{
+  /* Nothing yet */
+  choice->choice = A_NONE;
+  choice->want   = 0;
+}
+
+/********************************************************************** 
+  Evaluate gold worth of a single clause in a treaty. Note that it
+  sometimes matter a great deal who is giving what to whom, and
+  sometimes (such as with treaties) it does not matter at all.
+***********************************************************************/
+static int ai_goldequiv_clause(struct player *pplayer, 
+                               struct player *aplayer,
+                               struct Clause *pclause,
+                               struct ai_data *ai)
+{
+  int worth[MAX_NUM_PLAYERS]; /* worth of what X gives */
+  int i;
+  bool give = (pplayer == pclause->from);
+  int receiver, giver;
+
+  for (i = 0; i < MAX_NUM_PLAYERS; i++) {
+    worth[i] = 0;
+  }
+
+  giver = pclause->from->player_no;
+  if (give) {
+    receiver = aplayer->player_no;
+  } else {
+    receiver = pplayer->player_no;
+  }
+
+  switch (pclause->type) {
+  case CLAUSE_ADVANCE: {
+    int tech_cost;
+
+    if (give) {
+      tech_cost = ai_goldequiv_tech(aplayer, pclause->value);
+    } else {
+      tech_cost = ai_goldequiv_tech(pplayer, pclause->value);
+    }
+
+    /* Share and expect being shared brotherly between allies */
+    if (pplayers_allied(pplayer, aplayer)) {
+      tech_cost /= 2;
+    }
+
+    /* Calculate in tech leak to our enemies, guess 50% chance */
+    if (give) { 
+      players_iterate(eplayer) {
+        if (pplayers_allied(aplayer, eplayer) && aplayer != eplayer
+            && get_invention(eplayer, pclause->value) != TECH_KNOWN) {
+          worth[eplayer->player_no] -= 
+              ai_goldequiv_tech(eplayer, pclause->value) / 2;
+        }
+      } players_iterate_end;
+    }
+    worth[receiver] += tech_cost;
+    /* FIXME: We should calculate use of tech for allies too, but we
+       need to look just how the tech exchange code turns out 
+       first. - Per */
+  } break;
+
+  case CLAUSE_ALLIANCE:
+  case CLAUSE_PEACE:
+  case CLAUSE_CEASEFIRE: {
+    /* TODO: Note that right now most of this code is dead code because
+     * we set war_desire to zero for everyone but our no 1 target at
+     * another place in the code. - Per */
+    int war_desire = ai->diplomacy.other[aplayer->player_no].war_desire;
+
+    /* Attitude adjustment: Don't be too eager to get into a relationship
+     * that you can't stomach getting out of. */
+    if (ai_attitude(ai, DIP_BACKSTABBER)) {
+      war_desire /= 1.5;
+    }
+    if (ai_attitude(ai, DIP_TRUSTWORTHY)) {
+      war_desire *= 1.5;
+    }
+
+    /* Breaking treaties give us penalties on future diplomacy, so
+     * avoid flip-flopping treaty/war with our enemy. */
+    if (aplayer == ai->diplomacy.target 
+        && !ai_attitude(ai, DIP_BACKSTABBER)) {
+      war_desire *= 3;
+    }
+
+    /* No peace to our chosen victim if we are militarist */
+    if (aplayer == ai->diplomacy.target 
+        && ai_attitude(ai, DIP_MILITARIST)) {
+      worth[pplayer->player_no] = -FC_INFINITY;
+    }
+
+    /* We don't want treaties that obstruct our aims, but if war_desire
+       is negative then we want 'em this much. */
+    worth[pplayer->player_no] += -(war_desire * TRADE_WEIGHTING
+                                   * city_list_size(&aplayer->cities));
+    freelog(LOG_DIPL, "(%s ai diplo) Calculating pact with %s as (%d*%d*%d=)%d",
+            pplayer->name, aplayer->name,
+            war_desire, TRADE_WEIGHTING, city_list_size(&aplayer->cities),
+            worth[pplayer->player_no]);
+
+    /* Modify for peace */
+    if (pclause->type == CLAUSE_PEACE) { 
+      if (!pplayers_non_attack(pplayer, aplayer)) {
+        diplo_notify(aplayer, "%s says: Let us first cease hostilies, %s",
+                     pplayer->name, aplayer->name);
+        return -FC_INFINITY;
+      } else {
+        worth[pplayer->player_no] *= 1.5;
+      }
+    }
+
+    /* Modify for alliance */
+    if (pclause->type == CLAUSE_ALLIANCE) {
+      if (!pplayers_in_peace(pplayer, aplayer)) {
+        diplo_notify(aplayer, "%s says: Let us first cease hostilies, %s",
+                     pplayer->name, aplayer->name);
+        return -FC_INFINITY;
+      } else {
+        worth[pplayer->player_no] *= 3;
+      }
+    }
+
+    /* Modify for reputation */
+    i = (GAME_DEFAULT_REPUTATION - aplayer->reputation) 
+        * city_list_size(&aplayer->cities);
+    if (i != 0) {
+      worth[pplayer->player_no] -= i;
+      freelog(LOG_DIPL, "(%s ai diplo) %s has reputation %d, penalised with %d", 
+              pplayer->name, aplayer->name, aplayer->reputation, i);
+    }
+  } break;
+
+  case CLAUSE_GOLD:
+    worth[receiver] += pclause->value;
+    break;
+
+  case CLAUSE_SEAMAP:
+    /* Very silly algorithm 1: Sea map more worth if enemy has more
+       cities. Reasoning is he has more use of seamap for settling
+       new areas the more cities he has already. */
+    if (!give || pplayers_allied(pplayer, aplayer)) {
+      /* Useless to us - we're omniscient! And allies get it for free! */
+      worth[receiver] = 0;
+      break;
+    }
+    worth[receiver] += 25 * city_list_size(&aplayer->cities);
+    if (give && ai_attitude(ai, DIP_XENOPHOBE)) {
+      worth[receiver] *= 3; /* "And what exactly do you want with this...?" */
+    }
+    break;
+
+  case CLAUSE_MAP:
+    /* Very silly algorithm 2: Land map more worth the more cities
+       we have, since we expose all of these to the enemy. */
+    if (!give || pplayers_allied(pplayer, aplayer)) {
+      /* Useless to us - we're omniscient! And allies get it for free! */
+      worth[receiver] = 0;
+      break;
+    }
+    worth[receiver] += 75 * city_list_size(&pplayer->cities);
+    /* Inflate numbers if not peace */
+    if (!pplayers_in_peace(pplayer, aplayer)) { 
+      if (!give && ai_attitude(ai, DIP_TRADER)) {
+        worth[receiver] *= 2;
+      } else if (give && ai_attitude(ai, DIP_MILITARIST)) {
+        worth[receiver] *= 10;
+      } else {
+        worth[receiver] *= 3;
+      }
+    }
+    if (give && ai_attitude(ai, DIP_XENOPHOBE)) { 
+      worth[giver] -= FC_INFINITY; /* NEVER!!! */
+    }
+    break;
+
+  case CLAUSE_CITY:
+    worth[receiver] += ai_goldequiv_city(
+        city_list_find_id(&(pclause->from)->cities, pclause->value));
+    if (give) {
+      /* AI must be crazy to trade away its cities, but traders do/are */
+      if (ai_attitude(ai, DIP_TRADER) 
+          && pplayers_in_peace(pplayer, aplayer)) {
+        worth[receiver] *= 2;
+      } else {
+        worth[receiver] *= 15;
+      }
+    }
+    break;
+
+  case CLAUSE_VISION:
+    if (give) {
+      if (pplayers_allied(pplayer, aplayer)) {
+        worth[receiver] = 0;
+      } else {
+        /* so out of the question */
+        worth[receiver] += FC_INFINITY;
+      }
+    } else {
+      worth[receiver] = 1; /* We are omniscient, so... */
+    }
+    break;
+  } /* end of switch */
+
+  i = 0; /* balance */
+
+  /* Check externalities */
+  players_iterate(eplayer) {
+    /* We are supposed to give away something, check how this benefits
+       our enemies */
+    if (give && eplayer != aplayer && pplayers_at_war(eplayer, pplayer)) {
+      i += worth[eplayer->player_no]; 
+    }
+    /* We receive something, check how this benefits our friends */
+    if (!give && eplayer != pplayer && eplayer != aplayer 
+        && pplayers_allied(eplayer, pplayer)) {
+      i -= worth[eplayer->player_no];
+    }
+  } players_iterate_end;
+
+  /* wrt pplayer */
+  i += worth[pplayer->player_no]; 
+  i -= worth[aplayer->player_no];
+
+  /* Returns balance of what they offer vs what we offer */
+  if (give) {
+    freelog(LOG_DIPL, "(%s ai diplo) evaluating clause from %s to %s as worth %d",
+            pplayer->name, pplayer->name, aplayer->name, i);
+  } else {
+    freelog(LOG_DIPL, "(%s ai diplo) evaluating clause from %s to %s as worth %d",
+           pplayer->name, aplayer->name, pplayer->name, i);
+  }
+  return i;
+}
+
+/********************************************************************** 
+  pplayer is AI player, aplayer is the other player involved, treaty
+  is the treaty being considered. It is all a question about money :-)
+***********************************************************************/
+void ai_evaluate_treaty(struct player *pplayer, struct player *aplayer,
+                        struct Treaty *ptreaty)
+{
+  struct packet_diplomacy_info packet;
+  int balance = 0;
+  bool has_treaty = FALSE;
+  struct ai_data *ai = ai_data_get(pplayer);
+
+  assert(!is_barbarian(pplayer));
+
+  packet.plrno0 = pplayer->player_no;
+  packet.plrno1 = aplayer->player_no;
+  packet.plrno_from = pplayer->player_no;
+
+  /* Evaluate clauses */
+  clause_list_iterate(ptreaty->clauses, pclause) {
+    balance += ai_goldequiv_clause(pplayer, aplayer, pclause, ai);
+    if (is_pact_clause(pclause->type)) {
+      has_treaty = TRUE;
+    }
+  } clause_list_iterate_end;
+
+  /* If we are at war, and no peace is offered, then no deal */
+  if (pplayers_at_war(pplayer, aplayer) && !has_treaty) {
+    return;
+  }
+
+  /* Accept if balance is good */
+  if (balance >= 0) {
+/*
+    clause_list_iterate(ptreaty->clauses, pclause) {
+      if (pclause->type == CLAUSE_ALLIANCE)
+        diplo_notify(aplayer, "%s says: Yes, may we forever stand united, %s",
+                     pplayer->name, aplayer->name);
+      if (pclause->type == CLAUSE_PEACE)
+        diplo_notify(aplayer, "%s says: Yes, peace in our time!",
+                     pplayer->name);
+      if (pclause->type == CLAUSE_CEASEFIRE)
+        diplo_notify(aplayer, "%s says: Agreed. No more hostilities, %s",
+                     pplayer->name, aplayer->name);
+    } clause_list_iterate_end;
+*/ /* <<<--- this must be after BOTH sides have agreed! */
+    handle_diplomacy_accept_treaty(pplayer, &packet);
+  }
+}
+
+/********************************************************************** 
+  Return TRUE iff given player has given attitude.
+***********************************************************************/
+static bool ai_attitude(struct ai_data *ai, enum diplomacy_type dtype)
+{
+  return BOOL_VAL(ai->diplomacy.personality & dtype);
+}
+
+/********************************************************************** 
+  Calculate our desire to go to war against aplayer (or our hatred of
+  aplayer).
+***********************************************************************/
+static int ai_war_desire(struct player *pplayer, struct player *aplayer,
+                         struct ai_data *ai)
+{
+  int kill_desire, arrival, our_arrival;
+  struct player_spaceship *ship = &aplayer->spaceship;
+  struct player_spaceship *our_ship = &pplayer->spaceship;
+
+  /* Show some weakness */
+  if (!pplayers_at_war(pplayer, aplayer)
+      && ai_attitude(ai, DIP_TRUSTWORTHY)) {
+    return 0;
+  }
+
+  /* We can aim for an allied victory */
+  if (!ai_attitude(ai, DIP_MEGALOMANIAC)
+      && pplayers_allied(pplayer, aplayer)) {
+    return 0;
+  }
+
+  /* Number of cities is a player's base potential. */
+  kill_desire = city_list_size(&aplayer->cities);
+
+  /* Count settlers in production for us, indicating our expansionism,
+   * while counting all enemy settlers as (worst case) indicators of
+   * enemy expansionism */
+  city_list_iterate(pplayer->cities, pcity) {
+    if (pcity->is_building_unit 
+        && unit_type_flag(pcity->currently_building, F_CITIES)) {
+      kill_desire -= 1;
+    }
+  } city_list_iterate_end;
+  unit_list_iterate(aplayer->units, punit) { 
+    if (unit_flag(punit, F_CITIES)) { kill_desire += 1; }
+  } unit_list_iterate_end;
+
+  /* Count big cities as twice the threat */
+  city_list_iterate(aplayer->cities, pcity) {
+    kill_desire += pcity->size > 8 ? 1 : 0;
+  } city_list_iterate_end;
+
+  /* Tech lead is worrisome */
+  kill_desire += MAX(aplayer->research.techs_researched -
+                     pplayer->research.techs_researched, 0);
+
+  /* Spacerace loss we will not allow! */
+  if (ship->state >= SSHIP_STARTED) {
+    /* add potential */
+    kill_desire += city_list_size(&aplayer->cities);
+  }
+  if (our_ship->state >= SSHIP_LAUNCHED) { 
+    our_arrival = MAX((int) our_ship->travel_time - 
+        (game.year - our_ship->launch_year), 1);
+  } else { our_arrival = FC_INFINITY; }
+  if (ship->state >= SSHIP_LAUNCHED) { 
+    arrival = MAX((int) ship->travel_time - 
+        (game.year - ship->launch_year), 1);
+    if (arrival < our_arrival) {
+      /* The first division is for the unlikely case of several 
+         simultaneous ship launches, the second to avoid overflows */
+      kill_desire = FC_INFINITY / arrival / 2;
+      ai->diplomacy.timer = FC_INFINITY;
+      ai->diplomacy.strategy = WIN_CAPITAL;
+    }
+  }
+
+  /* Jealousy */
+  /* FIME: add score comparisons here, but add code for cacheing
+     score results first, or we will spam the CPU - Per */
+
+  return kill_desire;
+}
+
+/********************************************************************** 
+  Calculate relative military strength of us vs him
+  TODO: special checks for nukes (they inflate our numbers), and 
+  add in allies
+***********************************************************************/
+static int ai_war_fear(struct player *pplayer, struct player *aplayer,
+                       struct ai_data *ai)
+{
+  int them = 1;
+
+  /* relative military strength */
+  unit_list_iterate(aplayer->units, punit) {
+    them += ai_unit_attack_desirability(punit->type);
+  } unit_list_iterate_end;
+
+  return (them / ai->diplomacy.mil_strength) 
+         - (ai->diplomacy.mil_strength / them);
+}
+
+/********************************************************************** 
+  How much is tech worth to player measured in gold
+***********************************************************************/
+static int ai_goldequiv_tech(struct player *pplayer, Tech_Type_id tech)
+{
+  int worth;
+
+  if (get_invention(pplayer, tech) == TECH_KNOWN) {
+    return 0;
+  }
+  worth = total_bulbs_required_for_goal(pplayer, tech) * TRADE_WEIGHTING;
+  worth += pplayer->ai.tech_want[tech] / 2; /* often way too much */
+  if (get_invention(pplayer, tech) == TECH_REACHABLE) {
+    worth /= 2;
+  }
+  freelog(LOG_DIPL, "(%s ai diplo) %s goldequiv'ed to %d (had want %d)",
+          pplayer->name, get_tech_name(pplayer, tech), worth, 
+          pplayer->ai.tech_want[tech]);
+
+  return worth;
+}
+
+/********************************************************************** 
+  How much is city worth measured in gold
+***********************************************************************/
+static int ai_goldequiv_city(struct city *pcity)
+{
+  int worth;
+  struct player *pplayer = city_owner(pcity);
+
+  worth = pcity->size * 125; /* reasonable base cost */
+  built_impr_iterate(pcity, impr) {
+    if (improvement_types[impr].is_wonder && !wonder_obsolete(impr)) {
+      worth += improvement_types[impr].build_cost;
+    } else {
+      worth += (improvement_types[impr].build_cost / 4);
+    }
+  } built_impr_iterate_end;
+  if (city_unhappy(pcity)) {
+    worth *= 0.75;
+  }
+  freelog(LOG_DIPL, "(%s ai diplo) city %s goldequiv'ed to %d", 
+          pplayer->name, pcity->name, worth);
+
+  return worth;
+}
+
+/********************************************************************** 
+  Only ever called for AI players and never for barbarians.
+***********************************************************************/
+void ai_diplomacy_calculate(struct player *pplayer, struct ai_data *ai)
+{
+  int war_desire = 0;
+  int war_fear = 0;
+  struct player *target = NULL;
+
+  /* Stop war against a dead player */
+  if (ai->diplomacy.target && !ai->diplomacy.target->is_alive) {
+    freelog(LOG_DIPL, "(%s ai diplo) Target player %s is dead. Victory!",
+            pplayer->name, ai->diplomacy.target->name);
+    ai->diplomacy.timer = 0;
+    ai->diplomacy.target = NULL;
+    if (ai->diplomacy.strategy == WIN_CAPITAL) {
+      ai->diplomacy.strategy = WIN_OPEN;
+    }
+  }
+
+  /* Calculate our military strength */
+  ai->diplomacy.mil_strength = 1;
+  unit_list_iterate(pplayer->units, punit) {
+     ai->diplomacy.mil_strength += ai_unit_attack_desirability(punit->type);
+  } unit_list_iterate_end;
+
+  /* Ensure that we don't prematurely end an ongoing war */
+  if (ai->diplomacy.timer-- > 0) {
+    return;
+  }
+
+  /* Calculate our fears and desires, and find desired war target */
+  players_iterate(aplayer) {
+    enum diplstate_type ds = pplayer_get_diplstate(pplayer, aplayer)->type;
+
+    /* We don't fear/hate ourselves, those we don't know and those we're
+     * allied to (unless we're the backstabbing type) */
+    if (aplayer == pplayer
+        || ds == DS_NO_CONTACT
+        || (ds == DS_ALLIANCE && !ai_attitude(ai, DIP_BACKSTABBER))) {
+      continue;
+    }
+    ai->diplomacy.other[aplayer->player_no].war_desire =
+      ai_war_desire(pplayer, aplayer, ai);
+    ai->diplomacy.other[aplayer->player_no].war_fear =
+      ai_war_fear(pplayer, aplayer, ai);
+
+    /* Loyalty: hate our allies' enemies */
+    players_iterate(eplayer) {
+      if (pplayers_allied(pplayer, eplayer)
+          && !ai_attitude(ai, DIP_BACKSTABBER)
+          && pplayers_at_war(aplayer, eplayer)) {
+        ai->diplomacy.other[aplayer->player_no].war_desire *= 2;
+      }
+    } players_iterate_end;
+
+    /* Strongly prefer players we are at war with already */
+    if (pplayers_non_attack(pplayer, aplayer)) {
+      ai->diplomacy.other[aplayer->player_no].war_desire /= 2;
+    }
+    freelog(LOG_DIPL, "(%s ai diplo) Against %s we have war desire %d and fear %d",
+            pplayer->name, aplayer->name,
+            ai->diplomacy.other[aplayer->player_no].war_desire,
+            ai->diplomacy.other[aplayer->player_no].war_fear);
+
+    /* Find best target */
+    if (ai->diplomacy.other[aplayer->player_no].war_desire > war_desire) {
+      target = aplayer;
+      war_desire = ai->diplomacy.other[aplayer->player_no].war_desire;
+      war_fear = ai->diplomacy.other[aplayer->player_no].war_fear;
+    }
+  } players_iterate_end;
+
+  if (!target) {
+    freelog(LOG_DIPL, "(%s ai diplo) Found no target.", pplayer->name);
+    return;
+  }
+
+  if (target != ai->diplomacy.target) {
+    if (ai->diplomacy.target) {
+      freelog(LOG_DIPL, "(%s ai diplo) Changing target from %s to %s",
+              pplayer->name, ai->diplomacy.target->name, target->name);
+    } else {
+      freelog(LOG_DIPL, "(%s ai diplo) Setting target to %s",
+              pplayer->name, target->name);
+    }
+    ai->diplomacy.target = target;
+  }
+  if (!pplayers_at_war(pplayer, target)) {
+    diplo_notify(target, "%s says: Peace in ... some other time", pplayer->name);
+    handle_player_cancel_pact(pplayer, target->player_no);
+    /* continue war at least in this arbitrary number of turns to show some spine */
+    ai->diplomacy.timer = 6;
+  }
+
+  /* Opportunism, Inc */
+  players_iterate(aplayer) {
+    if (ai->diplomacy.other[aplayer->player_no].spam > 0) {
+      ai->diplomacy.other[aplayer->player_no].spam--;
+    }
+    if (is_barbarian(aplayer)    /* no diplomacy */
+        || aplayer == pplayer    /* no self-indulgence */
+        || aplayer == target) {  /* and no mercy */
+      continue;
+    }
+    /* Talk is cheap, and so is peace */
+    ai->diplomacy.other[aplayer->player_no].war_desire = 0;
+    /* TODO: actually add code to do peace treaty here */
+    if (ai->diplomacy.other[aplayer->player_no].spam > 0) {
+      /* Don't spam */
+      continue;
+    }
+    /* Canvass support from existing friends for our war, and try to
+     * make friends with enemies. Then we wait some turns until next time
+     * we spam them with our gibbering chatter. */
+    ai->diplomacy.other[aplayer->player_no].spam = myrand(4)+3;
+    if (pplayers_allied(pplayer, aplayer)) {
+      diplo_notify(aplayer, "%s says: Greetings our most trustworthy ally, "
+                   "we call upon you to destroy our enemy, %s", pplayer->name,
+                   target->name);
+      freelog(LOG_DIPL, "(%s ai diplo) demanding support from %s to crush %s",
+              pplayer->name, aplayer->name, target->name);
+    } else if (pplayers_non_attack(pplayer, aplayer)) {
+      diplo_notify(aplayer, "%s says: Greetings friend, may we suggest "
+                   "a joint campaign against %s?", pplayer->name, target->name);
+      freelog(LOG_DIPL, "(%s ai diplo) requesting support from %s to crush %s",
+              pplayer->name, aplayer->name, target->name);
+      /* add check if we want to get allied here, if reputation good */
+    } else if (pplayers_at_war(pplayer, aplayer)) {
+      diplo_notify(aplayer, "%s says: %s is threatening us both, may we suggest"
+                   " a cessation of hostilities?", pplayer->name, target->name);
+      freelog(LOG_DIPL, "(%s ai diplo) requesting peace from %s to crush %s",
+              pplayer->name, aplayer->name, target->name);
+    }
+  } players_iterate_end;
+}
diff -urNX freeciv/diff_ignore freeciv/ai/advdiplomacy.h freeciv-dipl/ai/advdiplomacy.h
--- freeciv/ai/advdiplomacy.h	1970-01-01 01:00:00.000000000 +0100
+++ freeciv-dipl/ai/advdiplomacy.h	2002-11-01 23:34:46.000000000 +0100
@@ -0,0 +1,30 @@
+/********************************************************************** 
+ Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+***********************************************************************/
+#ifndef FC__ADVATTITUDE_H
+#define FC__ADVATTITUDE_H
+
+struct player;
+struct ai_choice;
+struct Treaty;
+struct Clause;
+struct ai_data;
+
+void diplomacy_advisor_choose_tech(struct player *pplayer, 
+                                   struct ai_choice *choice);
+
+void ai_evaluate_treaty(struct player *pplayer, struct player *aplayer,
+                        struct Treaty *ptreaty);
+
+void ai_diplomacy_calculate(struct player *pplayer, struct ai_data *ai);
+
+#endif  /* FC__ADVATTITUDE_H */
diff -urNX freeciv/diff_ignore freeciv/ai/aidata.c freeciv-dipl/ai/aidata.c
--- freeciv/ai/aidata.c	2002-09-27 14:18:56.000000000 +0200
+++ freeciv-dipl/ai/aidata.c	2002-11-02 00:09:35.000000000 +0100
@@ -25,6 +25,7 @@
 #include "unittools.h"
 #include "maphand.h"
 
+#include "advdiplomacy.h"
 #include "advmilitary.h"
 #include "aicity.h"
 #include "aitools.h"
@@ -183,6 +184,12 @@
       ai->stats.workers[ptile->continent]++;
     }
   } unit_list_iterate_end;
+
+  /* Diplomacy */
+
+  if (pplayer->ai.control && game.diplomacy && !is_barbarian(pplayer)) {
+    ai_diplomacy_calculate(pplayer, ai);
+  }
 }
 
 /**************************************************************************
@@ -197,6 +204,26 @@
 }
 
 /**************************************************************************
+  Initialize with sane values
+**************************************************************************/
+void ai_data_init(struct player *pplayer) {
+  struct ai_data *ai = &aidata[pplayer->player_no];
+  int i;
+
+  ai->diplomacy.target = NULL;
+  ai->diplomacy.strategy = WIN_OPEN;
+  ai->diplomacy.timer = 0;
+  ai->diplomacy.personality = 0;
+  ai->diplomacy.mil_strength = 0;
+
+  for (i = 0; i < MAX_NUM_PLAYERS; i++) {
+    ai->diplomacy.other[i].war_desire = 0;
+    ai->diplomacy.other[i].war_fear = 0;
+    ai->diplomacy.other[i].spam = 0;
+  }
+}
+
+/**************************************************************************
   Do some sanity checks then return a pointer to our data
 **************************************************************************/
 struct ai_data *ai_data_get(struct player *pplayer) {
diff -urNX freeciv/diff_ignore freeciv/ai/aidata.h freeciv-dipl/ai/aidata.h
--- freeciv/ai/aidata.h	2002-08-31 02:55:28.000000000 +0200
+++ freeciv-dipl/ai/aidata.h	2002-11-02 00:09:12.000000000 +0100
@@ -19,7 +19,42 @@
  * start of every turn. 
  */
 
+enum winning_strategy {
+  WIN_OPEN,     /* still undetermined */
+  WIN_WAR,      /* we have no other choice than to crush all opposition */
+  WIN_SPACE,    /* we will race for space, peace very important */
+  WIN_HUNT,     /* enemy has F_GAMELOSS unit which we will hunt down */
+  WIN_CAPITAL   /* we cannot win unless we take war_target's capital */
+};
+
+/* FIXME: these should be set by difficulty and civworld */
+enum diplomacy_type {
+  DIP_NONE=0,           /* No attitude */
+  DIP_PACIFIST=1,       /* War desire -50% if positive */
+  DIP_MILITARIST=2,     /* War desire +50% if positive */
+  DIP_TRADER=4,         /* Worth of our offer -25%, trade cities */
+  DIP_GREEDY=8,         /* Worth of our offer +50% */
+  DIP_XENOPHOBE=16,     /* Only ever agrees to ceasefire and tech */
+  DIP_TRUSTWORTHY=32,   /* Does not break treaties unless violated */
+  DIP_BACKSTABBER=64,   /* Happily agrees to anything and then... */
+  DIP_MEGALOMANIAC=128, /* Does not share victory */
+};
+
 struct ai_data {
+  /* AI diplomacy */
+  struct {
+    enum winning_strategy strategy;
+    int timer; /* pursue our goals with some stubbornness */
+    struct {
+      int war_desire; /* desire for war or peace */
+      int war_fear;   /* fear of this player's military might */
+      int spam;       /* timer to avoid spamming a player with chat */
+    } other[MAX_NUM_PLAYERS];
+    struct player *target;    /* concentrate on this player */
+    int mil_strength;         /* Estimate of our military strength */
+    int personality;          /* Personality traits */
+  } diplomacy;
+
   /* Long-term threats, not to be confused with short-term danger */
   struct {
     bool invasions;   /* check if we need to consider invasions */
@@ -47,6 +82,8 @@
   int num_continents; /* last time we updated our continent data */
 };
 
+void ai_data_init(struct player *pplayer);
+
 void ai_data_turn_init(struct player *pplayer);
 void ai_data_turn_done(struct player *pplayer);
 
diff -urNX freeciv/diff_ignore freeciv/ai/Makefile.am freeciv-dipl/ai/Makefile.am
--- freeciv/ai/Makefile.am	2002-11-01 17:21:28.000000000 +0100
+++ freeciv-dipl/ai/Makefile.am	2002-11-01 21:16:16.000000000 +0100
@@ -21,6 +21,8 @@
 		advmilitary.h	\
 		advscience.c	\
 		advscience.h	\
+		advdiplomacy.c	\
+		advdiplomacy.h	\
 		advspace.c	\
 		advspace.h	\
 		advtrade.c	\
diff -urNX freeciv/diff_ignore freeciv/client/gui-gtk/plrdlg.c freeciv-dipl/client/gui-gtk/plrdlg.c
--- freeciv/client/gui-gtk/plrdlg.c	2002-08-19 23:28:01.000000000 +0200
+++ freeciv-dipl/client/gui-gtk/plrdlg.c	2002-11-02 00:16:18.000000000 +0100
@@ -479,10 +479,11 @@
   if (pplayer->is_alive 
       && pplayer != game.player_ptr
       && player_has_embassy(game.player_ptr, pplayer)) {
-    if (pplayer->is_connected)
+    if (pplayer->is_connected || pplayer->ai.control) {
       gtk_widget_set_sensitive(players_meet_command, TRUE);
-    else
+    } else {
       gtk_widget_set_sensitive(players_meet_command, FALSE);
+    }
     gtk_widget_set_sensitive(players_int_command, TRUE);
     return;
   }
diff -urNX freeciv/diff_ignore freeciv/client/gui-gtk-2.0/plrdlg.c freeciv-dipl/client/gui-gtk-2.0/plrdlg.c
--- freeciv/client/gui-gtk-2.0/plrdlg.c	2002-08-13 01:06:07.000000000 +0200
+++ freeciv-dipl/client/gui-gtk-2.0/plrdlg.c	2002-11-02 00:16:36.000000000 +0100
@@ -479,10 +479,11 @@
   if (pplayer->is_alive 
       && pplayer != game.player_ptr
       && player_has_embassy(game.player_ptr, pplayer)) {
-    if (pplayer->is_connected)
+    if (pplayer->is_connected || pplayer->ai.control) {
       gtk_widget_set_sensitive(players_meet_command, TRUE);
-    else
+    } else {
       gtk_widget_set_sensitive(players_meet_command, FALSE);
+    }
     gtk_widget_set_sensitive(players_int_command, TRUE);
     return;
   }
diff -urNX freeciv/diff_ignore freeciv/client/gui-win32/plrdlg.c freeciv-dipl/client/gui-win32/plrdlg.c
--- freeciv/client/gui-win32/plrdlg.c	2002-08-09 00:07:44.000000000 +0200
+++ freeciv-dipl/client/gui-win32/plrdlg.c	2002-11-02 00:18:00.000000000 +0100
@@ -239,10 +239,11 @@
   if (pplayer->is_alive 
       && pplayer != game.player_ptr
       && player_has_embassy(game.player_ptr, pplayer)) {
-    if (pplayer->is_connected)
+    if (pplayer->is_connected || pplayer->ai.control) {
       EnableWindow(GetDlgItem(players_dialog,ID_PLAYERS_MEET), TRUE);
-    else
+    } else {
       EnableWindow(GetDlgItem(players_dialog,ID_PLAYERS_MEET), FALSE);
+    }
     EnableWindow(GetDlgItem(players_dialog,ID_PLAYERS_INT), TRUE);
     return;
   }
diff -urNX freeciv/diff_ignore freeciv/client/gui-xaw/plrdlg.c freeciv-dipl/client/gui-xaw/plrdlg.c
--- freeciv/client/gui-xaw/plrdlg.c	2002-08-09 00:07:44.000000000 +0200
+++ freeciv-dipl/client/gui-xaw/plrdlg.c	2002-11-02 00:17:05.000000000 +0100
@@ -302,10 +302,11 @@
     if (pplayer->is_alive
         && pplayer != game.player_ptr
         && player_has_embassy(game.player_ptr, pplayer)) {
-      if(pplayer->is_connected)
+      if (pplayer->is_connected || pplayer->ai.control) {
 	XtSetSensitive(players_meet_command, TRUE);
-      else
+      } else {
 	XtSetSensitive(players_meet_command, FALSE);
+      }
       XtSetSensitive(players_int_command, TRUE);
       return;
     }
diff -urNX freeciv/diff_ignore freeciv/common/game.c freeciv-dipl/common/game.c
--- freeciv/common/game.c	2002-10-24 16:47:55.000000000 +0200
+++ freeciv-dipl/common/game.c	2002-11-01 21:43:30.000000000 +0100
@@ -665,6 +665,7 @@
   game.researchcost = GAME_DEFAULT_RESEARCHCOST;
   game.diplcost    = GAME_DEFAULT_DIPLCOST;
   game.diplchance  = GAME_DEFAULT_DIPLCHANCE;
+  game.diplomacy   = GAME_DEFAULT_DIPLOMACY;
   game.freecost    = GAME_DEFAULT_FREECOST;
   game.conquercost = GAME_DEFAULT_CONQUERCOST;
   game.settlers    = GAME_DEFAULT_SETTLERS;
diff -urNX freeciv/diff_ignore freeciv/common/game.h freeciv-dipl/common/game.h
--- freeciv/common/game.h	2002-09-29 21:59:54.000000000 +0200
+++ freeciv-dipl/common/game.h	2002-11-01 21:43:46.000000000 +0100
@@ -77,6 +77,7 @@
   int researchcost; /* Multiplier on cost of new research */
   int diplcost, freecost, conquercost;
   int diplchance;
+  bool diplomacy;
   int cityfactor;
   int citymindist;
   int civilwarsize;
@@ -311,6 +312,7 @@
 #define GAME_DEFAULT_DIPLCOST        0
 #define GAME_MIN_DIPLCOST            0
 #define GAME_MAX_DIPLCOST            100
+#define GAME_DEFAULT_DIPLOMACY       TRUE
 
 #define GAME_DEFAULT_FOGOFWAR        TRUE
 
diff -urNX freeciv/diff_ignore freeciv/common/player.c freeciv-dipl/common/player.c
--- freeciv/common/player.c	2002-09-29 21:59:54.000000000 +0200
+++ freeciv-dipl/common/player.c	2002-11-01 21:16:16.000000000 +0100
@@ -573,6 +573,20 @@
 }
 
 /***************************************************************
+returns true iff players are allied or at peace
+***************************************************************/
+bool pplayers_in_peace(const struct player *pplayer,
+		    const struct player *pplayer2)
+{
+  enum diplstate_type ds = pplayer_get_diplstate(pplayer, pplayer2)->type;
+  if (pplayer == pplayer2)
+    return TRUE;
+  if (is_barbarian(pplayer) || is_barbarian(pplayer2))
+    return FALSE;
+  return (ds == DS_ALLIANCE || ds == DS_PEACE);
+}
+
+/***************************************************************
 returns true iff players have peace or cease-fire
 ***************************************************************/
 bool pplayers_non_attack(const struct player *pplayer,
diff -urNX freeciv/diff_ignore freeciv/common/player.h freeciv-dipl/common/player.h
--- freeciv/common/player.h	2002-11-01 17:21:28.000000000 +0100
+++ freeciv-dipl/common/player.h	2002-11-01 21:16:16.000000000 +0100
@@ -253,6 +253,8 @@
 		    const struct player *pplayer2);
 bool pplayers_allied(const struct player *pplayer,
 		    const struct player *pplayer2);
+bool pplayers_in_peace(const struct player *pplayer,
+                    const struct player *pplayer2);
 bool pplayers_non_attack(const struct player *pplayer,
 			const struct player *pplayer2);
 
diff -urNX freeciv/diff_ignore freeciv/server/diplhand.c freeciv-dipl/server/diplhand.c
--- freeciv/server/diplhand.c	2002-09-29 21:59:54.000000000 +0200
+++ freeciv-dipl/server/diplhand.c	2002-11-01 21:32:22.000000000 +0100
@@ -36,6 +36,8 @@
 #include "settlers.h"
 #include "unittools.h"
 
+#include "advdiplomacy.h"
+
 #include "diplhand.h"
 
 static struct genlist treaties;
@@ -416,6 +418,12 @@
 				 PACKET_DIPLOMACY_REMOVE_CLAUSE, packet);
       lsend_packet_diplomacy_info(&plr1->connections, 
 				 PACKET_DIPLOMACY_REMOVE_CLAUSE, packet);
+      if (plr0->ai.control) {
+        ai_evaluate_treaty(plr0, plr1, ptreaty);
+      }
+      if (plr1->ai.control) {
+        ai_evaluate_treaty(plr1, plr0, ptreaty);
+      }
     }
   }
 
@@ -459,6 +467,12 @@
       lsend_packet_diplomacy_info(&plr1->connections, 
 				 PACKET_DIPLOMACY_CREATE_CLAUSE, 
 				 packet);
+      if (plr0->ai.control) {
+        ai_evaluate_treaty(plr0, plr1, ptreaty);
+      }
+      if (plr1->ai.control) {
+        ai_evaluate_treaty(plr1, plr0, ptreaty);
+      }
     }
   }
 }
@@ -524,18 +538,26 @@
   if (!check_packet(packet, FALSE))
     return;
 
+  assert(plr0 != plr1);
+
   plr0=&game.players[packet->plrno0];
   plr1=&game.players[packet->plrno1];
 
   if (!find_treaty(plr0, plr1)) {
-    if (plr0->ai.control || plr1->ai.control) {
-      notify_player(plr0, _("AI controlled players cannot participate in "
-			    "diplomatic meetings."));
+    if (is_barbarian(plr0) || is_barbarian(plr1)) {
+      notify_player(plr0, _("Your diplomatic envoy was decapitated!"));
       return;
     }
-
-    if (player_has_embassy(plr0, plr1) && plr0->is_connected && 
-	plr0->is_alive && plr1->is_connected && plr1->is_alive) {
+    if (!game.diplomacy && (plr0->ai.control || plr1->ai.control)) {
+      notify_player(plr0, _("AI controlled players cannot participate in " 
+                            "diplomatic meetings."));
+      return;
+    }
+    if (player_has_embassy(plr0, plr1) 
+        && (plr0->is_connected || plr0->ai.control)
+	&& plr0->is_alive 
+        && (plr1->is_connected || plr1->ai.control) 
+	&& plr1->is_alive) {
       struct Treaty *ptreaty;
 
       ptreaty=fc_malloc(sizeof(struct Treaty));
@@ -573,6 +595,7 @@
     return;
   }
   players_iterate(other_player) {
+
     if ( (ptreaty=find_treaty(pplayer, other_player))) {
       struct packet_diplomacy_info packet;
       
diff -urNX freeciv/diff_ignore freeciv/server/plrhand.c freeciv-dipl/server/plrhand.c
--- freeciv/server/plrhand.c	2002-11-01 19:00:26.000000000 +0100
+++ freeciv-dipl/server/plrhand.c	2002-11-01 21:16:16.000000000 +0100
@@ -1562,10 +1562,10 @@
    * but for now AI players are always at war.
    */
   players_iterate(other_player) {
-    cplayer->diplstates[other_player->player_no].type = DS_WAR;
+    cplayer->diplstates[other_player->player_no].type = DS_NEUTRAL;
     cplayer->diplstates[other_player->player_no].has_reason_to_cancel = 0;
     cplayer->diplstates[other_player->player_no].turns_left = 0;
-    other_player->diplstates[cplayer->player_no].type = DS_WAR;
+    other_player->diplstates[cplayer->player_no].type = DS_NEUTRAL;
     other_player->diplstates[cplayer->player_no].has_reason_to_cancel = 0;
     other_player->diplstates[cplayer->player_no].turns_left = 0;
     
@@ -1591,7 +1591,7 @@
   for(i = 0; i<game.num_tech_types ; i++)
     cplayer->research.inventions[i] = pplayer->research.inventions[i];
   cplayer->turn_done = TRUE; /* Have other things to think about - paralysis*/
-  cplayer->embassy = 0;   /* all embassys destroyed */
+  cplayer->embassy = 0;   /* all embassies destroyed */
 
   /* Do the ai */
 
diff -urNX freeciv/diff_ignore freeciv/server/srv_main.c freeciv-dipl/server/srv_main.c
--- freeciv/server/srv_main.c	2002-10-24 16:48:00.000000000 +0200
+++ freeciv-dipl/server/srv_main.c	2002-11-01 23:30:02.000000000 +0100
@@ -89,6 +89,7 @@
 #include "unithand.h"
 #include "unittools.h"
 
+#include "advdiplomacy.h"
 #include "advmilitary.h"
 #include "aidata.h"
 #include "aihand.h"
@@ -1859,6 +1860,11 @@
 
   (void) send_server_info_to_metaserver(TRUE, FALSE);
 
+  /* Initialize AI data structures */
+  players_iterate(pplayer) {
+    ai_data_init(pplayer);
+  } players_iterate_end;
+
   if(game.is_new_game) {
     load_rulesets();
     /* otherwise rulesets were loaded when savegame was loaded */