citytools.c

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/***********************************************************************
 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.
***********************************************************************/
 
#ifdef HAVE_CONFIG_H
#include <fc_config.h>
#endif
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
/* utility */
#include "bitvector.h"
#include "fcintl.h"
#include "log.h"
#include "mem.h"
#include "rand.h"
#include "shared.h"
#include "support.h"
 
/* common */
#include "ai.h"
#include "base.h"
#include "citizens.h"
#include "city.h"
#include "counters.h"
#include "culture.h"
#include "events.h"
#include "game.h"
#include "government.h"
#include "improvement.h"
#include "idex.h"
#include "map.h"
#include "movement.h"
#include "packets.h"
#include "player.h"
#include "requirements.h"
#include "research.h"
#include "road.h"
#include "specialist.h"
#include "tech.h"
#include "traderoutes.h"
#include "unit.h"
#include "unitlist.h"
#include "vision.h"
 
/* common/aicore */
#include "cm.h"
 
/* common/scriptcore */
#include "luascript_types.h"
 
/* server */
#include "actiontools.h"
#include "barbarian.h"
#include "citizenshand.h"
#include "cityturn.h"
#include "gamehand.h"           /* send_game_info() */
#include "maphand.h"
#include "notify.h"
#include "plrhand.h"
#include "sanitycheck.h"
#include "sernet.h"
#include "spacerace.h"
#include "srv_main.h"
#include "techtools.h"
#include "unithand.h"
#include "unittools.h"
 
/* server/advisors */
#include "advbuilding.h"
#include "advgoto.h"
#include "infracache.h"
 
/* server/scripting */
#include "script_server.h"
 
/* ai */
#include "handicaps.h"
 
/* ai */
#include "handicaps.h"
 
#include "citytools.h"
 
 
/* Queue for pending auto_arrange_workers() */
static struct city_list *arrange_workers_queue = nullptr;
 
/* Suppress sending cities during game_load() and end_phase() */
static bool send_city_suppressed = FALSE;
 
static bool city_workers_queue_remove(struct city *pcity);
 
static void announce_trade_route_removal(struct city *pc1, struct city *pc2,
                                         bool source_gone)
  fc__attribute((nonnull (1, 2)));
 
/************************************************************************/
void city_freeze_workers(struct city *pcity)
{
  pcity->server.workers_frozen++;
}
 
/************************************************************************/
void city_thaw_workers(struct city *pcity)
{
  pcity->server.workers_frozen--;
  fc_assert(pcity->server.workers_frozen >= 0);
  if (pcity->server.workers_frozen == 0
      && pcity->server.needs_arrange != CNA_NOT) {
    city_refresh(pcity); /* Citizen count sanity */
    auto_arrange_workers(pcity);
  }
}
 
/************************************************************************/
void city_freeze_workers_queue(struct city *pcity)
{
  if (arrange_workers_queue == nullptr) {
    arrange_workers_queue = city_list_new();
  } else if (city_list_find_number(arrange_workers_queue, pcity->id)) {
    /* City might have been arranged since it was originally put to the queue.
     * Make sure needs_arrange is set again. */
    if (pcity->server.needs_arrange == CNA_NOT) {
      pcity->server.needs_arrange = CNA_NORMAL;
    }
    return;
  }
 
  city_list_prepend(arrange_workers_queue, pcity);
  city_freeze_workers(pcity);
  if (pcity->server.needs_arrange == CNA_NOT) {
    pcity->server.needs_arrange = CNA_NORMAL;
  }
}
 
/************************************************************************/
static bool city_workers_queue_remove(struct city *pcity)
{
  if (arrange_workers_queue == nullptr) {
    return FALSE;
  }
 
  return city_list_remove(arrange_workers_queue, pcity);
}
 
/************************************************************************/
void city_thaw_workers_queue(void)
{
  if (arrange_workers_queue == nullptr) {
    return;
  }
 
  city_list_iterate(arrange_workers_queue, pcity) {
    city_thaw_workers(pcity);
  } city_list_iterate_end;
 
  city_list_destroy(arrange_workers_queue);
  arrange_workers_queue = nullptr;
}
 
/************************************************************************/
static int evaluate_city_name_priority(struct tile *ptile,
                                       const struct nation_city *pncity,
                                       int default_priority)
{
  /* Lower values mean higher priority. */
  float priority = (float)default_priority;
  enum nation_city_preference goodness;
 
  /* Increasing this value will increase the difference caused by
     (non-)matching terrain. A matching terrain is mult_factor
     "better" than an unlisted terrain, which is mult_factor
     "better" than a non-matching terrain. */
  const float mult_factor = 1.4;
  bool river = FALSE;
 
  /*
   * If natural city names aren't being used, we just return
   * the base value. This will have the effect of the first-listed
   * city being used. We do this here rather than special-casing
   * it elsewhere because this localizes everything to this
   * function, even though it's a bit inefficient.
   */
  if (!game.server.natural_city_names) {
    return default_priority;
  }
 
  /*
   * Assuming we're using the natural city naming system, we use
   * an internal alorithm to calculate the priority of each name.
   * It's a pretty fuzzy algorithm; we basically do the following:
   *   - Change the priority scale from 0..n to 10..n+10. This means
   *     each successive city is 10% lower priority than the first.
   *   - Multiply by a semi-random number. This has the effect of
   *     decreasing rounding errors in the successive calculations,
   *     as well as introducing a smallish random effect.
   *   - Check over all the applicable terrains, and
   *     multiply or divide the priority based on whether or not
   *     the terrain matches. See comment below.
   */
 
  priority += 10.0;
  priority *= 10.0 + fc_rand(5);
 
  /*
   * The terrain priority in the struct nation_city will be either
   * -1, 0, or 1. We therefore take this as-is if the terrain is
   * present, or negate it if not.
   *
   * The reason we multiply as well as divide the value is so
   * that cities that don't care what terrain they are on (which
   * is the default) will be left in the middle of the pack.
   * If we _only_ multiplied (or divided), then cities that had more
   * terrain labels would have their priorities hurt (or helped).
   */
  goodness = nation_city_river_preference(pncity);
  extra_type_by_cause_iterate(EC_ROAD, priver) {
    if (tile_has_extra(ptile, priver)
        && road_has_flag(extra_road_get(priver), RF_RIVER)) {
      river = TRUE;
      break;
    }
  } extra_type_by_cause_iterate_end;
  if (!river) {
    goodness = nation_city_preference_revert(goodness);
  }
 
  switch (goodness) {
  case NCP_DISLIKE:
    priority *= mult_factor;
    break;
  case NCP_NONE:
    break;
  case NCP_LIKE:
    priority /= mult_factor;
    break;
  }
 
  terrain_type_iterate(pterrain) {
    /* Now we do the same for every available terrain. */
    goodness = nation_city_terrain_preference(pncity, pterrain);
    if (!is_terrain_near_tile(&(wld.map), ptile, pterrain, TRUE)) {
      goodness = nation_city_preference_revert(goodness);
    }
    switch (goodness) {
    case NCP_DISLIKE:
      priority *= mult_factor;
      break;
    case NCP_NONE:
      break;
    case NCP_LIKE:
      priority /= mult_factor;
    }
  } terrain_type_iterate_end;
 
  return (int) priority;
}
 
/************************************************************************/
static bool is_default_city_name(const char *name, struct player *pplayer)
{
  nation_city_list_iterate(nation_cities(nation_of_player(pplayer)),
                           pncity) {
    if (0 == fc_strcasecmp(name, nation_city_name(pncity))) {
      return TRUE;
    }
  } nation_city_list_iterate_end;
  return FALSE;
}
 
/************************************************************************/
static const char *search_for_city_name(struct tile *ptile,
                                        const struct nation_city_list *
                                        default_cities,
                                        struct player *pplayer)
{
  int choice = 0, priority, best_priority = -1;
  const char *name;
  const char *best_name = nullptr;
 
  nation_city_list_iterate(default_cities, pncity) {
    name = nation_city_name(pncity);
    if (game_city_by_name(name) == nullptr
        && is_allowed_city_name(pplayer, name, nullptr, 0)) {
      priority = evaluate_city_name_priority(ptile, pncity, choice++);
      if (-1 == best_priority || priority < best_priority) {
        best_priority = priority;
        best_name = name;
      }
    }
  } nation_city_list_iterate_end;
 
  return best_name;
}
 
/************************************************************************/
bool is_allowed_city_name(struct player *pplayer, const char *cityname,
                          char *error_buf, size_t bufsz)
{
  struct connection *pconn = conn_by_user(pplayer->username);
 
  /* Mode 1: A city name has to be unique for each player. */
  if (CNM_PLAYER_UNIQUE == game.server.allowed_city_names
      && city_list_find_name(pplayer->cities, cityname)) {
    if (error_buf) {
      fc_snprintf(error_buf, bufsz, _("You already have a city called %s."),
                  cityname);
    }
    return FALSE;
  }
 
  /* Modes 2,3: A city name has to be globally unique. */
  if ((CNM_GLOBAL_UNIQUE == game.server.allowed_city_names
       || CNM_NO_STEALING == game.server.allowed_city_names)
      && game_city_by_name(cityname)) {
    if (error_buf) {
      fc_snprintf(error_buf, bufsz,
                  _("A city called %s already exists."), cityname);
    }
    return FALSE;
  }
 
  /* General rule: any name in our ruleset is allowed. */
  if (is_default_city_name(cityname, pplayer)) {
    return TRUE;
  }
 
  /*
   * Mode 3: Check that the proposed city name is not in another
   * player's default city names. Note the name will already have been
   * allowed if it is in this player's default city names list.
   */
  if (CNM_NO_STEALING == game.server.allowed_city_names) {
    struct player *pother = nullptr;
 
    players_iterate(player2) {
      if (player2 != pplayer && is_default_city_name(cityname, player2)) {
        pother = player2;
        break;
      }
    } players_iterate_end;
 
    if (pother != nullptr) {
      if (error_buf) {
        fc_snprintf(error_buf, bufsz,
                    _("Can't use %s as a city name. It is reserved for %s."),
                    cityname, nation_plural_for_player(pother));
      }
      return FALSE;
    }
  }
 
  /* To prevent abuse, only players with HACK access (usually local
   * connections) can use non-ascii names. Otherwise players could use
   * confusing garbage names in multi-player games.
   *
   * We can even reach here for an AI player, if all the cities of
   * the original nation are exhausted and the backup nations have
   * non-ascii names in them. */
  if (!is_ascii_name(cityname)
      && (!pconn || pconn->access_level != ALLOW_HACK)) {
    if (error_buf) {
      fc_snprintf(error_buf, bufsz,
                  _("%s is not a valid name. Only ASCII or "
                    "ruleset names are allowed for cities."),
                  cityname);
    }
    return FALSE;
  }
 
 
  return TRUE;
}
 
/************************************************************************/
const char *city_name_suggestion(struct player *pplayer, struct tile *ptile)
{
  struct nation_type *pnation = nation_of_player(pplayer);
  const char *name;
 
  log_verbose("Suggesting city name for %s at (%d,%d)",
              player_name(pplayer), TILE_XY(ptile));
 
  /* First try default city names. */
  name = search_for_city_name(ptile, nation_cities(pnation), pplayer);
  if (name != nullptr) {
    log_debug("Default city name found: %s.", name);
    return name;
  }
 
  /* Not found... Let's try a straightforward algorithm to look through
   * nations to find a city name.
   *
   * We start by adding the player's nation to the queue. Then we proceed:
   * - Pick a random nation from the queue.
   * - If it has a valid city name, use that.
   * - Otherwise, add all parent and child nations to the queue.
   * - If the queue is empty, add all remaining nations to it and continue.
   *
   * Variables used:
   * - nation_list is a queue of nations to look through.
   * - nations_selected tells whether each nation is in the queue already
   * - queue_size gives the size of the queue (number of nations in it).
   * - i is the current position in the queue.
   * Note that nations aren't removed from the queue after they're processed.
   * New nations are just added onto the end. */
  {
    struct nation_type *nation_list[nation_count()];
    bool nations_selected[nation_count()];
    int queue_size = 1, i = 0, idx;
 
    memset(nations_selected, 0, sizeof(nations_selected));
    nation_list[0] = pnation;
    nations_selected[nation_index(pnation)] = TRUE;
 
    while (i < nation_count()) {
      for (; i < queue_size; i++) {
 
        if (0 < i) {
          /* Pick a random nation from the queue. */
          const int which = i + fc_rand(queue_size - i);
          struct nation_type *tmp = nation_list[i];
 
          nation_list[i] = nation_list[which];
          nation_list[which] = tmp;
 
          pnation = nation_list[i];
          log_debug("Looking through %s.", nation_rule_name(pnation));
          name = search_for_city_name(ptile, nation_cities(pnation), pplayer);
 
          if (name != nullptr) {
            return name;
          }
        }
 
        /* Append the nation's civil war nations into the search tree. */
        nation_list_iterate(pnation->server.civilwar_nations, n) {
          idx = nation_index(n);
          if (!nations_selected[idx]) {
            nation_list[queue_size] = n;
            nations_selected[idx] = TRUE;
            queue_size++;
            log_debug("Child %s.", nation_rule_name(n));
          }
        } nation_list_iterate_end;
 
        /* Append the nation's parent nations into the search tree. */
        nation_list_iterate(pnation->server.parent_nations, n) {
          idx = nation_index(n);
          if (!nations_selected[idx]) {
            nation_list[queue_size] = n;
            nations_selected[idx] = TRUE;
            queue_size++;
            log_debug("Parent %s.", nation_rule_name(n));
          }
        } nation_list_iterate_end;
      }
 
      /* Still not found; append all remaining nations. */
      allowed_nations_iterate(n) {
        idx = nation_index(n);
        if (!nations_selected[idx]) {
          nation_list[queue_size] = n;
          nations_selected[nation_index(n)] = TRUE;
          queue_size++;
          log_debug("Misc nation %s.", nation_rule_name(n));
        }
      } allowed_nations_iterate_end;
    }
  }
 
  /* Not found in rulesets, make a default name. */
  {
    static char tempname[MAX_LEN_CITYNAME];
    int i;
 
    log_debug("City name not found in rulesets.");
    for (i = 1; i <= map_num_tiles(); i++ ) {
      fc_snprintf(tempname, MAX_LEN_CITYNAME, _("City no. %d"), i);
      if (game_city_by_name(tempname) == nullptr) {
        return tempname;
      }
    }
 
    fc_assert_msg(FALSE, "Failed to generate a city name.");
    sz_strlcpy(tempname, _("A poorly-named city"));
    return tempname;
  }
}
 
/************************************************************************/
int build_points_left(struct city *pcity)
{
  int cost = city_production_build_shield_cost(pcity);
 
  return cost - pcity->shield_stock;
}
 
/************************************************************************/
static void transfer_unit(struct unit *punit, struct city *tocity,
                          bool rehome, bool verbose)
{
  struct player *from_player = unit_owner(punit);
  struct player *to_player = city_owner(tocity);
 
  /* Transferring a dying GameLoss unit as part of the loot for
   * killing it caused gna bug #23676. */
  fc_assert_ret_msg(!punit->server.dying,
                    "Tried to transfer the dying unit %d.",
                    punit->id);
 
  if (from_player == to_player) {
    fc_assert_ret(rehome);
    log_verbose("Changed homecity of %s %s to %s",
                nation_rule_name(nation_of_player(from_player)),
                unit_rule_name(punit),
                city_name_get(tocity));
    if (verbose) {
      notify_player(from_player, unit_tile(punit),
                    E_UNIT_RELOCATED, ftc_server,
                    _("Changed homecity of %s to %s."),
                    unit_link(punit),
                    city_link(tocity));
    }
  } else {
    struct tile *utile = unit_tile(punit);
    struct city *in_city = tile_city(utile);
 
    if (utype_player_already_has_this_unique(to_player,
                                             unit_type_get(punit))) {
      /* This is a unique unit that to_player already has. A transfer would
       * break the rule that a player only may have one unit of each unique
       * unit type. */
 
      log_debug("%s already have a %s. Can't transfer from %s",
                nation_rule_name(nation_of_player(to_player)),
                unit_rule_name(punit),
                nation_rule_name(nation_of_player(from_player)));
 
      if (utype_has_flag(unit_type_get(punit), UTYF_GAMELOSS)) {
        /* Try to save game loss units. */
        bounce_unit(punit, verbose);
      } else {
        /* Kill the unique unit. */
 
        if (verbose) {
          notify_player(from_player, unit_tile(punit),
                        E_UNIT_LOST_MISC, ftc_server,
                        /* TRANS: Americans ... Leader */
                        _("The %s already have a %s. Can't transfer yours."),
                        nation_plural_for_player(to_player),
                        unit_tile_link(punit));
        }
 
        wipe_unit(punit, ULR_CITY_LOST, nullptr);
      }
 
      return;
    }
 
    if (in_city) {
      log_verbose("Transferred %s in %s from %s to %s",
                  unit_rule_name(punit), city_name_get(in_city),
                  nation_rule_name(nation_of_player(from_player)),
                  nation_rule_name(nation_of_player(to_player)));
      if (verbose) {
        notify_player(from_player, unit_tile(punit),
                      E_UNIT_RELOCATED, ftc_server,
                      _("Transferred %s in %s from %s to %s."),
                      unit_link(punit),
                      city_link(in_city),
                      nation_plural_for_player(from_player),
                      nation_plural_for_player(to_player));
      }
    } else if (can_unit_exist_at_tile(&(wld.map), punit, tocity->tile)) {
      log_verbose("Transferred %s from %s to %s",
                  unit_rule_name(punit),
                  nation_rule_name(nation_of_player(from_player)),
                  nation_rule_name(nation_of_player(to_player)));
      if (verbose) {
        notify_player(from_player, unit_tile(punit),
                      E_UNIT_RELOCATED, ftc_server,
                      _("Transferred %s from %s to %s."),
                      unit_link(punit),
                      nation_plural_for_player(from_player),
                      nation_plural_for_player(to_player));
      }
    } else {
      log_verbose("Could not transfer %s from %s to %s",
                  unit_rule_name(punit),
                  nation_rule_name(nation_of_player(from_player)),
                  nation_rule_name(nation_of_player(to_player)));
      if (verbose) {
        notify_player(from_player, unit_tile(punit),
                      E_UNIT_LOST_MISC, ftc_server,
                      /* TRANS: Polish Destroyer ... German <city> */
                      _("%s %s lost in transfer to %s %s"),
                      nation_adjective_for_player(from_player),
                      unit_tile_link(punit),
                      nation_adjective_for_player(to_player),
                      city_link(tocity));
      }
      wipe_unit(punit, ULR_CITY_LOST, nullptr);
      return;
    }
 
    unit_make_contact(punit, utile, to_player);
  }
  unit_change_homecity_handling(punit, tocity, rehome);
}
 
/************************************************************************/
void transfer_city_units(struct player *pplayer, struct player *pvictim,
                         struct unit_list *units, struct city *pcity,
                         struct city *exclude_city,
                         int kill_outside, bool verbose)
{
  struct tile *ptile = pcity->tile;
  int saved_id = pcity->id;
  const char *name = city_name_get(pcity);
 
  /* Transfer enemy units in the city to the new owner.
   * Only relevant if we are transferring to another player. */
  if (pplayer != pvictim) {
    unit_list_iterate_safe((ptile)->units, vunit)  {
      if (vunit->server.dying) {
        /* Don't transfer or bounce a dying unit. It will soon be gone
         * anyway.
         *
         * Bouncing a dying unit isn't a good idea.
         * Remaining death handling may do things meant for its current
         * location to the new location. (Example: Stack death)
         * bounce_unit() will wipe the unit if it can't be bounced. Wiping
         * the dying unit isn't a good idea. The remaining death handling
         * code will try to read from it.
         *
         * Transferring a dying GameLoss unit as part of the loot for
         * killing it caused gna bug #23676. */
        continue;
      }
 
      /* Don't transfer units already owned by new city-owner --wegge */
      if (unit_owner(vunit) == pvictim) {
        /* Determine whether unit was homeless. If it was, we don't give
         * it a homecity, only change ownership.
         * We have to search the transferred city's former units because
         * the unit may have been made only temporarily homeless during
         * city transfer. */
        bool homeless = (vunit->homecity == 0)
          && !unit_list_search(units, vunit);
 
        /* vunit may die during transfer_unit().
         * unit_list_remove() is still safe using vunit pointer, as
         * pointer is not used for dereferencing, only as value.
         * Not sure if it would be safe to unlink first and transfer only
         * after that. Not sure if it is correct to unlink at all in
         * some cases, depending which list 'units' points to. */
        transfer_unit(vunit, pcity, !homeless, verbose);
        unit_list_remove(units, vunit);
      } else if (!pplayers_allied(pplayer, unit_owner(vunit))) {
        /* The owner of vunit is allied to pvictim but not to pplayer */
        bounce_unit(vunit, verbose);
      }
    } unit_list_iterate_safe_end;
  }
 
  if (!city_exist(saved_id)) {
    saved_id = 0;
  }
 
  /* Any remaining units supported by the city are either given new home
   * cities or maybe destroyed */
  unit_list_iterate_safe(units, vunit) {
    struct city *new_home_city = tile_city(unit_tile(vunit));
 
    if (vunit->server.dying) {
      /* Don't transfer or destroy a dying unit. It will soon be gone
       * anyway.
       *
       * Transferring a dying GameLoss unit as part of the loot for
       * killing it caused gna bug #23676. */
      continue;
    }
 
    if (new_home_city && new_home_city != exclude_city
        && city_owner(new_home_city) == unit_owner(vunit)) {
      /* Unit is in another city: make that the new homecity,
       * unless that city is actually the same city (happens if disbanding)
       * Unit had a homecity since it was supported, so rehome. */
      transfer_unit(vunit, new_home_city, TRUE, verbose);
    } else if ((kill_outside == -1
                || real_map_distance(unit_tile(vunit), ptile) <= kill_outside)
               && saved_id) {
      /* Else transfer to specified city. */
      transfer_unit(vunit, pcity, TRUE, verbose);
      if (unit_tile(vunit) == ptile && !pplayers_allied(pplayer, pvictim)) {
        /* Unit is inside city being transferred, bounce it. */
        bounce_unit(vunit, TRUE);
      }
    } else {
      /* The unit is lost.  Call notify_player (in all other cases it is
       * called automatically). */
      log_verbose("Lost %s %s at (%d,%d) when %s was lost.",
                  nation_rule_name(nation_of_unit(vunit)),
                  unit_rule_name(vunit), TILE_XY(unit_tile(vunit)), name);
      if (verbose) {
        notify_player(unit_owner(vunit), unit_tile(vunit),
                      E_UNIT_LOST_MISC, ftc_server,
                      _("%s lost along with control of %s."),
                      unit_tile_link(vunit), name);
      }
      wipe_unit(vunit, ULR_CITY_LOST, nullptr);
    }
  } unit_list_iterate_safe_end;
 
#ifdef FREECIV_DEBUG
  unit_list_iterate(pcity->units_supported, punit) {
    if (punit->server.dying) {
      /* Leave the dying alone. */
      continue;
    }
 
    fc_assert(punit->homecity == pcity->id);
    fc_assert(unit_owner(punit) == pplayer);
  } unit_list_iterate_end;
#endif /* FREECIV_DEBUG */
}
 
/************************************************************************/
struct city *find_closest_city(const struct tile *ptile,
                               const struct city *pexclcity,
                               const struct player *pplayer,
                               bool only_ocean, bool only_continent,
                               bool only_known, bool only_player,
                               bool only_enemy, const struct unit_class *pclass)
{
  Continent_id con;
  struct city *best_city = nullptr;
  int best_dist = -1;
 
  fc_assert_ret_val(ptile != nullptr, nullptr);
 
  if (pplayer != nullptr && only_player && only_enemy) {
    log_error("Non of my own cities will be at war with me!");
    return nullptr;
  }
 
  con = tile_continent(ptile);
 
  players_iterate(aplayer) {
    if (pplayer != nullptr && only_player && pplayer != aplayer) {
      /* Only cities of player 'pplayer' */
      continue;
    }
 
    if (pplayer != nullptr && only_enemy
        && !pplayers_at_war(pplayer, aplayer)) {
      /* Only cities of players at war with player 'pplayer' */
      continue;
    }
 
    city_list_iterate(aplayer->cities, pcity) {
      int city_dist;
 
      if (pexclcity && pexclcity == pcity) {
        /* not this city */
        continue;
      }
 
      city_dist = real_map_distance(ptile, city_tile(pcity));
 
      /* Find the closest city matching the requirements.
       * - closer than the current best city
       * - (if required) on the same continent
       * - (if required) adjacent to ocean
       * - (if required) only cities known by the player
       * - (if required) only cities native to the class */
      if ((best_dist == -1 || city_dist < best_dist)
          && (!only_continent || con == tile_continent(pcity->tile))
          && (!only_ocean || is_terrain_class_near_tile(&(wld.map),
                                                        city_tile(pcity), TC_OCEAN))
          && (!only_known
              || (map_is_known(city_tile(pcity), pplayer)
                  && map_get_player_site(city_tile(pcity), pplayer)->identity
                     > IDENTITY_NUMBER_ZERO))
          && (pclass == nullptr
              || is_native_near_tile(&(wld.map), pclass, city_tile(pcity)))) {
        best_dist = city_dist;
        best_city = pcity;
      }
    } city_list_iterate_end;
  } players_iterate_end;
 
  return best_city;
}
 
/************************************************************************/
static void raze_city(struct city *pcity)
{
  int razechance = game.server.razechance;
  bool city_remains = TRUE;
 
  /* Land barbarians are more likely to destroy city improvements */
  if (is_land_barbarian(city_owner(pcity))) {
    razechance += 30;
  }
 
  city_built_iterate(pcity, pimprove) {
    /* Small wonders should have already been removed by
     * transfer_city() (with 100% probability). */
    fc_assert(!is_small_wonder(pimprove));
    if (is_improvement(pimprove) && (fc_rand(100) < razechance)) {
      /* FIXME: Should maybe have conquering unit instead
       *        of nullptr as destroyer */
      city_remains = building_removed(pcity, pimprove, "razed", nullptr);
      if (!city_remains) {
        break;
      }
    }
  } city_built_iterate_end;
 
  if (city_remains) {
    nullify_prechange_production(pcity);
    pcity->shield_stock = 0;
  }
}
 
/************************************************************************/
static void reestablish_city_trade_routes(struct city *pcity)
{
  trade_routes_iterate_safe(pcity, proute) {
    bool keep_route;
    struct trade_route *back;
    struct city *partner = game_city_by_number(proute->partner);
 
    /* Remove the city's trade routes (old owner).
     * Do not announce removal as we might restore the route immediately below */
    back = remove_trade_route(pcity, proute, FALSE, FALSE);
 
    keep_route = can_cities_trade(pcity, partner)
      && can_establish_trade_route(pcity, partner, proute->goods->replace_priority);
 
    if (!keep_route) {
      enum trade_route_type type = cities_trade_route_type(pcity, partner);
      struct trade_route_settings *settings = trade_route_settings_by_type(type);
 
      if (settings->cancelling != TRI_CANCEL) {
        keep_route = TRUE;
      }
    }
 
    /* Readd the city's trade route (new owner) */
    if (keep_route) {
      trade_route_list_append(pcity->routes, proute);
      trade_route_list_append(partner->routes, back);
    } else {
      free(proute);
      free(back);
 
      /* Now announce the trade route removal */
      announce_trade_route_removal(pcity, partner, FALSE);
    }
 
    /* Refresh regardless; either it lost a trade route or the trade
     * route revenue changed. */
    city_refresh(partner);
    send_city_info(city_owner(partner), partner);
 
    /* Give the new owner infos about the city which has a trade route
     * with the transferred city. */
    if (game.info.reveal_trade_partner) {
      struct player *owner = city_owner(pcity);
 
      map_show_tile(owner, partner->tile);
      update_dumb_city(owner, partner);
      send_city_info(owner, partner);
    }
  } trade_routes_iterate_safe_end;
}
 
/************************************************************************/
static void build_free_small_wonders(struct player *pplayer,
                                     bv_imprs *had_small_wonders)
{
  int size = city_list_size(pplayer->cities);
 
  if (!game.server.savepalace) {
    /* Nothing to do */
    return;
  }
 
  if (size == 0) {
    /* The last city was removed or transferred to the enemy.
     * If the victim survives to found or acquire another city, they'll
     * get any savepalace initial buildings then. */
    return;
  }
 
  improvement_iterate(pimprove) {
    if (improvement_has_flag(pimprove, IF_SAVE_SMALL_WONDER)
        && BV_ISSET(*had_small_wonders, improvement_index(pimprove))) {
      /* FIXME: instead, find central city */
      struct city *pnew_city = city_list_get(pplayer->cities, fc_rand(size));
 
      fc_assert_action(city_from_small_wonder(pplayer, pimprove) == nullptr,
                       continue);
 
      city_add_improvement(pnew_city, pimprove);
 
      /*
       * send_player_cities() will recalculate all cities and send them to
       * the client.
       */
      send_player_cities(pplayer);
 
      notify_player(pplayer, city_tile(pnew_city), E_IMP_BUILD, ftc_server,
                    /* FIXME: should already be notified about city loss? */
                    /* TRANS: <building> ... <city> */
                    _("A replacement %s was built in %s."),
                    improvement_name_translation(pimprove),
                    city_link(pnew_city));
      /*
       * The enemies want to see the new capital in their intelligence
       * report.
       */
      send_city_info(nullptr, pnew_city);
    }
  } improvement_iterate_end;
}
 
/************************************************************************/
bool transfer_city(struct player *ptaker, struct city *pcity,
                   int kill_outside, bool transfer_unit_verbose,
                   bool resolve_stack, bool raze, bool build_free)
{
  bv_imprs had_small_wonders;
  struct vision *old_vision, *new_vision;
  struct unit_list *old_city_units = unit_list_new();
  struct player *pgiver = city_owner(pcity);
  struct tile *pcenter = city_tile(pcity);
  int saved_id = pcity->id;
  bool city_remains = TRUE;
  bool had_great_wonders = FALSE;
  const citizens old_taker_content_citizens = player_content_citizens(ptaker);
  const citizens old_giver_content_citizens = player_content_citizens(pgiver);
  const citizens old_taker_angry_citizens = player_angry_citizens(ptaker);
  const citizens old_giver_angry_citizens = player_angry_citizens(pgiver);
  bool taker_had_no_cities = (city_list_size(ptaker->cities) == 0);
  bool new_extras;
  int units_num = 0;
  const int ul_size = unit_list_size(pcenter->units);
  int central_units[ul_size + 1];
  bv_player *could_see_unit = nullptr;
  int i;
  const struct civ_map *nmap = &(wld.map);
 
  fc_assert_ret_val(pgiver != ptaker, TRUE);
 
  unit_list_iterate(pcenter->units, punit) {
    central_units[units_num++] = punit->id;
  } unit_list_iterate_end;
 
  if (units_num > 0) {
    could_see_unit = fc_calloc(sizeof(*could_see_unit), units_num);
 
    /* Remember what player see what unit. */
    for (i = 0; i < units_num; i++) {
      struct unit *aunit = game_unit_by_number(central_units[i]);
 
      BV_CLR_ALL(could_see_unit[i]);
      players_iterate(aplayer) {
        if (can_player_see_unit(aplayer, aunit)) {
          BV_SET(could_see_unit[i], player_index(aplayer));
        }
      } players_iterate_end;
    }
 
    fc_assert(i == units_num);
  }
 
  /* Remove AI control of the old owner. */
  CALL_PLR_AI_FUNC(city_lost, pcity->owner, pcity->owner, pcity);
 
  /* Forget old tasks */
  clear_worker_tasks(pcity);
 
  /* Forget old rally point */
  city_rally_point_clear(pcity);
 
  /* Clear pointer to old owner's access areas */
  if (pcity->aarea != nullptr) {
    city_list_remove(pcity->aarea->cities, pcity);
    pcity->aarea = nullptr;
  }
 
  /* Activate AI control of the new owner. */
  CALL_PLR_AI_FUNC(city_got, ptaker, ptaker, pcity);
 
  city_freeze_workers(pcity);
 
  unit_list_iterate(pcity->units_supported, punit) {
    unit_list_prepend(old_city_units, punit);
    /* Mark unit to have no homecity at all.
     * 1. We remove unit from units_supported list here,
     *    real_change_unit_homecity() should not attempt it.
     * 2. Otherwise we might delete the homecity from under the unit
     *    in the client */
    punit->homecity = 0;
    send_unit_info(nullptr, punit);
  } unit_list_iterate_end;
  unit_list_clear(pcity->units_supported);
 
  /* Remove all global improvement effects that this city confers (but
     then restore the local improvement list - we need this to restore
     the global effects for the new city owner) */
  BV_CLR_ALL(had_small_wonders);
  city_built_iterate(pcity, pimprove) {
    if (is_small_wonder(pimprove)) {
      /* Small wonders are really removed (not restored later). */
      building_removed(pcity, pimprove, "conquered", nullptr);
      BV_SET(had_small_wonders, improvement_index(pimprove));
    } else {
      city_remove_improvement(pcity, pimprove);
      if (is_great_wonder(pimprove)) {
        had_great_wonders = TRUE;
      }
      /* Note: internal turn here, next city_built_iterate(). */
      pcity->built[improvement_index(pimprove)].turn = game.info.turn; /*I_ACTIVE*/
    }
  } city_built_iterate_end;
 
  give_citymap_from_player_to_player(pcity, pgiver, ptaker);
  old_vision = pcity->server.vision;
  new_vision = vision_new(ptaker, pcenter);
  pcity->server.vision = new_vision;
  vision_reveal_tiles(new_vision, game.server.vision_reveal_tiles);
  vision_change_sight(new_vision, old_vision->radius_sq);
 
  ASSERT_VISION(new_vision);
 
  if (CNM_PLAYER_UNIQUE == game.server.allowed_city_names
      && city_list_find_name(ptaker->cities, city_name_get(pcity))) {
    char *old_city_name = fc_strdup(city_name_get(pcity));
 
    city_name_set(pcity, city_name_suggestion(ptaker, pcenter));
    notify_player(ptaker, pcenter, E_BAD_COMMAND, ftc_server,
                  _("You already had a city called %s."
                    " The city was renamed to %s."),
                  old_city_name,
                  city_link(pcity));
 
    free(old_city_name);
  }
 
  /* Has to follow the unfog call above. */
  city_list_remove(pgiver->cities, pcity);
  map_clear_border(pcenter);
  /* city_thaw_workers_queue() later */
 
  pcity->owner = ptaker;
  pcity->capital = CAPITAL_NOT;
  pcity->acquire_t = CACQ_CONQUEST;
  map_claim_ownership(pcenter, ptaker, pcenter, TRUE);
  city_list_prepend(ptaker->cities, pcity);
 
  if (could_see_unit != nullptr) {
    /* Hide/reveal units. Do it after vision have been given to taker, city
     * owner has been changed, and before any script could be spawned. */
    for (i = 0; i < units_num; i++) {
      struct unit *aunit = game_unit_by_number(central_units[i]);
 
      players_iterate(aplayer) {
        if (can_player_see_unit(aplayer, aunit)) {
          if (!BV_ISSET(could_see_unit[i], player_index(aplayer))
              && !aunit->server.dying) {
            /* Reveal 'aunit'. */
            send_unit_info(aplayer->connections, aunit);
          }
        } else {
          if (BV_ISSET(could_see_unit[i], player_index(aplayer))) {
            /* Hide 'aunit'. */
            unit_goes_out_of_sight(aplayer, aunit);
          }
        }
      } players_iterate_end;
    }
 
    fc_assert(i == units_num);
 
    free(could_see_unit);
    could_see_unit = nullptr;
  }
 
  transfer_city_units(ptaker, pgiver, old_city_units,
                      pcity, nullptr,
                      kill_outside, transfer_unit_verbose);
  /* The units themselves are already freed by transfer_city_units(). */
  unit_list_destroy(old_city_units);
 
  if (resolve_stack) {
    resolve_unit_stacks(pgiver, ptaker, transfer_unit_verbose);
  }
 
  if (!city_exist(saved_id)) {
    city_remains = FALSE;
  }
 
  /* Reset turns owner counters */
  if (city_remains) {
    city_counters_iterate(pcount) {
      if (pcount->type == CB_CITY_OWNED_TURNS) {
        pcity->counter_values[pcount->index] = 0;
      }
    } city_counters_iterate_end;
  }
 
  if (city_remains) {
    /* Update the city's trade routes. */
    reestablish_city_trade_routes(pcity);
 
    /* Clear CMA. */
    if (pcity->cm_parameter) {
      free(pcity->cm_parameter);
      pcity->cm_parameter = nullptr;
    }
 
    city_refresh(pcity);
  }
 
  /*
   * maybe_make_contact() MUST be called before city_map_update_all(),
   * since the diplomacy status can influence whether a tile is available.
   */
  maybe_make_contact(pcenter, ptaker);
 
  if (city_remains) {
    struct extra_type *upgradet;
 
    if (raze) {
      raze_city(pcity);
    }
 
    if (taker_had_no_cities) {
      /* If conqueror previously had no cities, we might need to give
       * them a palace etc */
      if (build_free) {
        city_build_free_buildings(pcity);
      } /* Else caller should probably ensure palace is built */
 
      BV_SET(ptaker->flags, PLRF_FIRST_CITY);
    }
 
    citizens_convert_conquest(pcity);
 
    /* Restore any global improvement effects that this city confers */
    city_built_iterate(pcity, pimprove) {
      city_add_improvement_with_gov_notice(pcity, pimprove,
                                           _("Transfer of %s"));
    } city_built_iterate_end;
 
    /* Set production to something valid for pplayer, if not.
     * (previously allowed building obsolete units.) */
    if (!can_city_build_now(nmap, pcity, &pcity->production, RPT_CERTAIN)) {
      advisor_choose_build(ptaker, pcity);
    }
 
    /* What wasn't obsolete for the old owner may be so now. */
    remove_obsolete_buildings_city(pcity, TRUE);
 
    new_extras = upgrade_city_extras(pcity, &upgradet);
 
    if (new_extras) {
      const char *clink = city_link(pcity);
 
      notify_player(ptaker, pcenter, E_CITY_TRANSFER, ftc_server,
                    _("The people in %s are stunned by your "
                      "technological insight!"),
                    clink);
 
      if (upgradet != nullptr) {
        notify_player(ptaker, pcenter, E_CITY_TRANSFER, ftc_server,
                      _("Workers spontaneously gather and upgrade "
                        "%s with %s."),
                      clink, extra_name_translation(upgradet));
      } else {
        notify_player(ptaker, pcenter, E_CITY_TRANSFER, ftc_server,
                      _("Workers spontaneously gather and upgrade "
                        "%s infrastructure."),
                      clink);
      }
      update_tile_knowledge(pcenter);
    }
 
    /* Build a new palace for free if the player lost their capital and
       savepalace is on. */
    build_free_small_wonders(pgiver, &had_small_wonders);
 
    /* Refresh the city's vision range, since it might be different
     * under the new owner. */
    city_refresh_vision(pcity);
 
    /* Update the national borders, within the current vision and culture.
     * This could leave a border ring around the city, updated later by
     * map_calculate_borders() at the next turn.
     */
    map_claim_border(pcenter, ptaker, -1);
    /* city_thaw_workers_queue() later */
 
    auto_arrange_workers(pcity); /* Does city_map_update_all() */
    city_thaw_workers(pcity);
    city_thaw_workers_queue();   /* After old city has a chance to work! */
    city_refresh_queue_add(pcity);
    /* No sanity check here as the city is not refreshed! */
  }
 
  if (city_remains) {
    /* Send city with updated owner information to giver and to everyone
     * having shared vision pact with them before they may
     * lose vision to it. When we later send info to everybody seeing the city,
     * they may not be included. */
    send_city_info(nullptr, pcity);
  }
 
  /* Remove the sight points from the giver. */
  vision_clear_sight(old_vision);
  vision_free(old_vision);
 
  /* Send wonder infos. */
  if (had_great_wonders) {
    send_game_info(nullptr);
    if (city_remains) {
      send_player_info_c(ptaker, nullptr);
 
      /* Refresh all cities of the taker to account for possible changes due
       * to player wide effects. */
      city_list_iterate(ptaker->cities, acity) {
        city_refresh_queue_add(acity);
      } city_list_iterate_end;
    } else {
      /* Refresh all cities to account for possible global effects. */
      cities_iterate(acity) {
        city_refresh_queue_add(acity);
      } cities_iterate_end;
    }
  }
  if (BV_ISSET_ANY(had_small_wonders) || had_great_wonders) {
    /* No need to send to detached connections. */
    send_player_info_c(pgiver, nullptr);
 
    /* Refresh all cities of the giver to account for possible changes due
     * to player wide effects. */
    city_list_iterate(pgiver->cities, acity) {
      city_refresh_queue_add(acity);
    } city_list_iterate_end;
  }
 
  /* Refresh all cities in the queue. */
  city_refresh_queue_processing();
  /* After the refresh the sanity check can be done. */
  sanity_check_city(pcity);
 
  if (city_remains) {
    /* Send information about conquered city to all players. */
    send_city_info(nullptr, pcity);
  }
 
  /* We may cross the EFT_EMPIRE_SIZE_* effects, then we will have to
   * refresh all cities for the player. */
  if (old_taker_content_citizens != player_content_citizens(ptaker)
      || old_taker_angry_citizens != player_angry_citizens(ptaker)) {
    city_refresh_for_player(ptaker);
  }
  if (old_giver_content_citizens != player_content_citizens(pgiver)
      || old_giver_angry_citizens != player_angry_citizens(pgiver)) {
    city_refresh_for_player(pgiver);
  }
 
  if (pgiver->primary_capital_id == saved_id) {
    update_capital(pgiver);
  }
 
  sync_cities();
 
  CALL_FUNC_EACH_AI(city_info, pcity);
 
  return city_remains;
}
 
/************************************************************************/
void city_build_free_buildings(struct city *pcity)
{
  struct player *pplayer;
  struct nation_type *nation;
  int i;
  bool has_small_wonders, has_great_wonders;
  bool first_city;
 
  fc_assert_ret(pcity != nullptr);
  pplayer = city_owner(pcity);
  fc_assert_ret(pplayer != nullptr);
  nation = nation_of_player(pplayer);
  fc_assert_ret(nation != nullptr);
 
  /* If this isn't the first city a player has ever had, they only get
   * any initial buildings with the SaveSmallWonder flag, and then only
   * if savepalace is enabled. */
  first_city = !player_has_flag(pplayer, PLRF_FIRST_CITY);
 
  has_small_wonders = FALSE;
  has_great_wonders = FALSE;
 
  /* Global free buildings. */
  for (i = 0; i < MAX_NUM_BUILDING_LIST; i++) {
    Impr_type_id n = game.rgame.global_init_buildings[i];
    struct impr_type *pimprove;
 
    if (n == B_LAST) {
      break;
    }
 
    pimprove = improvement_by_number(n);
    fc_assert_action(!is_great_wonder(pimprove), continue);
    if (first_city
        || (game.server.savepalace
            && improvement_has_flag(pimprove, IF_SAVE_SMALL_WONDER))) {
      city_add_improvement_with_gov_notice(pcity, pimprove,
         /* TRANS: Reason that a building was added to the city.
          *        Building is given for free to player's first city. */
                                           Q_("?initbldg:Free %s"));
      if (is_small_wonder(pimprove)) {
        has_small_wonders = TRUE;
      }
    }
  }
 
  /* Nation specific free buildings. */
  for (i = 0; i < MAX_NUM_BUILDING_LIST; i++) {
    Impr_type_id n = nation->init_buildings[i];
    struct impr_type *pimprove;
 
    if (n == B_LAST) {
      break;
    }
 
    pimprove = improvement_by_number(n);
    if (first_city
        || (game.server.savepalace
            && improvement_has_flag(pimprove, IF_SAVE_SMALL_WONDER))) {
      city_add_improvement_with_gov_notice(pcity, pimprove,
         /* TRANS: Reason that a building was added to the city.
          *        Building is given for free to player's first city. */
                                           Q_("?initbldg:Free %s"));
      if (is_small_wonder(pimprove)) {
        has_small_wonders = TRUE;
      } else if (is_great_wonder(pimprove)) {
        has_great_wonders = TRUE;
      }
    }
  }
 
  /* Update wonder infos. */
  if (has_great_wonders) {
    send_game_info(nullptr);
    /* No need to send to detached connections. */
    send_player_info_c(pplayer, nullptr);
  } else if (has_small_wonders) {
    /* No need to send to detached connections. */
    send_player_info_c(pplayer, nullptr);
  }
}
 
/************************************************************************/
void create_city(struct player *pplayer, struct tile *ptile,
                 const char *name, struct player *nationality)
{
  struct player *saved_owner = tile_owner(ptile);
  struct tile *saved_claimer = tile_claimer(ptile);
  struct city *pwork = tile_worked(ptile);
  struct city *pcity;
  const citizens old_content_citizens = player_content_citizens(pplayer);
  const citizens old_angry_citizens = player_angry_citizens(pplayer);
  const struct civ_map *nmap = &(wld.map);
 
  log_debug("create_city() %s", name);
 
  pcity = create_city_virtual(pplayer, ptile, name);
 
  /* Remove units no more seen. Do it before city is really put into
   * the game. */
  players_iterate(other_player) {
    if (can_player_see_units_in_city(other_player, pcity)
        || !map_is_known_and_seen(ptile, other_player, V_MAIN)) {
      continue;
    }
    unit_list_iterate(ptile->units, punit) {
      if (can_player_see_unit(other_player, punit)) {
        unit_goes_out_of_sight(other_player, punit);
      }
    } unit_list_iterate_end;
  } players_iterate_end;
 
  adv_city_alloc(pcity);
 
  tile_set_owner(ptile, pplayer, ptile); /* Temporarily */
  city_choose_build_default(nmap, pcity);
  pcity->id = identity_number();
 
  fc_mutex_allocate(&game.server.mutexes.city_list);
  idex_register_city(&wld, pcity);
  fc_mutex_release(&game.server.mutexes.city_list);
 
  if (city_list_size(pplayer->cities) == 0) {
    /* Free initial buildings, or at least a palace if they were
     * previously careless enough to lose all their cities */
    city_build_free_buildings(pcity);
    BV_SET(pplayer->flags, PLRF_FIRST_CITY);
  }
 
  /* Set up citizens nationality. */
  citizens_init(pcity);
 
  /* Place a worker at the is_city_center() is_free_worked().
   * It is possible to build a city on a tile that is already worked;
   * this will displace the worker on the newly-built city's tile -- Syela */
  tile_set_worked(ptile, pcity); /* Instead of city_map_update_worker() */
 
  if (pwork != nullptr) {
    /* Was previously worked by another city */
    /* Turn citizen into specialist. */
    pwork->specialists[DEFAULT_SPECIALIST]++;
    /* One less citizen. Citizen sanity will be handled later in
     * city_thaw_workers_queue() */
    pwork->server.synced = FALSE;
    city_freeze_workers_queue(pwork);
  }
 
  /* Update citizens. */
  citizens_update(pcity, nationality);
 
  /* Restore the old-owner information so removal
   * of territory claiming bases can work relative to it. */
  tile_set_owner(ptile, saved_owner, saved_claimer);
 
  /* Destroy any extras that don't belong in the city. */
  extra_type_iterate(pextra) {
    if (tile_has_extra(ptile, pextra)
        && !is_native_tile_to_extra(pextra, ptile)) {
      destroy_extra(ptile, pextra);
    }
  } extra_type_iterate_end;
 
  /* Build any extras that the city should have. */
  upgrade_city_extras(pcity, nullptr);
 
  /* Claim the ground we stand on */
  map_claim_ownership(ptile, pplayer, ptile, TRUE);
 
  /* Before arranging workers to show unknown land */
  pcity->server.vision = vision_new(pplayer, ptile);
  vision_reveal_tiles(pcity->server.vision, game.server.vision_reveal_tiles);
  city_refresh_vision(pcity);
  city_list_prepend(pplayer->cities, pcity);
 
  /* This is dependent on the current vision, so must be done after
   * vision is prepared and before arranging workers. */
  map_claim_border(ptile, pplayer, -1);
  /* city_thaw_workers_queue() later */
 
  /* Refresh the city. First a city refresh is done (this shouldn't
   * send any packets to the client because the city has no supported units)
   * then rearrange the workers. Note that auto_arrange_workers() does its
   * own refresh call; it is safest to do our own controlled city_refresh()
   * first. */
  city_refresh(pcity);
  auto_arrange_workers(pcity);
  city_thaw_workers_queue(); /* After new city has a chance to work! */
  city_refresh_queue_processing();
 
  /* Bases destroyed earlier may have had watchtower effect. Refresh
   * unit vision. */
  unit_list_refresh_vision(ptile->units);
 
  update_tile_knowledge(ptile);
 
  if (old_content_citizens != player_content_citizens(pplayer)
      || old_angry_citizens != player_angry_citizens(pplayer)) {
    /* We crossed the EFT_EMPIRE_SIZE_* effects, we have to refresh all
     * cities for the player. */
    city_refresh_for_player(pplayer);
  }
 
  pcity->server.synced = FALSE;
  send_city_info(nullptr, pcity);
  sync_cities(); /* Will also send pwork. */
 
  notify_player(pplayer, ptile, E_CITY_BUILD, ftc_server,
                _("You have founded %s."),
                city_link(pcity));
  maybe_make_contact(ptile, city_owner(pcity));
 
  unit_list_iterate((ptile)->units, punit) {
    struct city *home = game_city_by_number(punit->homecity);
 
    /* Catch fortress building, transforming into ocean, etc. */
    if (!can_unit_continue_current_activity(&(wld.map), punit)) {
      unit_activities_cancel(punit);
    }
 
    /* Update happiness (the unit may no longer cause unrest). */
    if (home) {
      if (city_refresh(home)) {
        /* Shouldn't happen, but better be safe than sorry. */
        auto_arrange_workers(home);
      }
      sanity_check_city(home);
      send_city_info(city_owner(home), home);
    }
  } unit_list_iterate_end;
 
  sanity_check_city(pcity);
 
  script_server_signal_emit("city_built", pcity);
 
  CALL_FUNC_EACH_AI(city_created, pcity);
  CALL_PLR_AI_FUNC(city_got, pplayer, pplayer, pcity);
}
 
/************************************************************************/
bool create_city_for_player(struct player *pplayer, struct tile *ptile,
                            const char *name, struct player *nationality)
{
  const struct civ_map *nmap = &(wld.map);
 
  if (is_enemy_unit_tile(ptile, pplayer)
      || !city_can_be_built_here(nmap, ptile, nullptr, FALSE)) {
    return FALSE;
  }
 
  if (!pplayer->is_alive) {
    pplayer->is_alive = TRUE;
    send_player_info_c(pplayer, nullptr);
  }
 
  if (name == nullptr || name[0] == '\0') {
    name = city_name_suggestion(pplayer, ptile);
  }
 
  if (nationality == nullptr) {
    nationality = pplayer;
  }
 
  map_show_tile(pplayer, ptile);
  create_city(pplayer, ptile, name, nationality);
 
  return TRUE;
}
 
/************************************************************************/
void remove_city(struct city *pcity)
{
  struct player *powner = city_owner(pcity);
  struct tile *pcenter = city_tile(pcity);
  bv_imprs had_small_wonders;
  struct vision *old_vision;
  int id = pcity->id; /* We need this even after memory has been freed */
  bool had_great_wonders = FALSE;
  const citizens old_content_citizens = player_content_citizens(powner);
  const citizens old_angry_citizens = player_angry_citizens(powner);
  struct dbv tile_processed;
  struct tile_list *process_queue;
  const char *ctl = city_tile_link(pcity);
  const struct civ_map *nmap = &(wld.map);
 
  CALL_PLR_AI_FUNC(city_lost, powner, powner, pcity);
  CALL_FUNC_EACH_AI(city_destroyed, pcity);
 
  BV_CLR_ALL(had_small_wonders);
  city_built_iterate(pcity, pimprove) {
    building_removed(pcity, pimprove, "city_destroyed", nullptr);
 
    if (is_small_wonder(pimprove)) {
      BV_SET(had_small_wonders, improvement_index(pimprove));
    } else if (is_great_wonder(pimprove)) {
      had_great_wonders = TRUE;
    }
  } city_built_iterate_end;
 
  /* Rehome units in other cities */
  unit_list_iterate_safe(pcity->units_supported, punit) {
    struct city *new_home_city = tile_city(unit_tile(punit));
 
    if (new_home_city
        && new_home_city != pcity
        && city_owner(new_home_city) == powner
        && !punit->server.dying) {
      transfer_unit(punit, new_home_city, TRUE, TRUE);
    }
  } unit_list_iterate_safe_end;
 
  /* Make sure ships are not left on land when city is removed. */
  unit_list_iterate_safe(pcenter->units, punit) {
    bool moved;
    const struct unit_type *punittype = unit_type_get(punit);
 
    /* can_exist_at_tile() would give wrong results, as
     * the city is still on map. */
    if (is_native_tile(punittype, pcenter)
        && (!utype_has_flag(punittype, UTYF_COAST_STRICT)
            || is_safe_ocean(nmap, pcenter))) {
      continue;
    }
 
    unit_activity_handling(punit, ACTIVITY_IDLE, ACTION_NONE);
    moved = FALSE;
    adjc_iterate(nmap, pcenter, tile1) {
      struct unit *ptrans;
 
      if (!moved && can_exist_at_tile(nmap, punittype, tile1)) {
        if (adv_could_unit_move_to_tile(punit, tile1) == 1) {
          /* Move */
          if (!can_unit_survive_at_tile(nmap, punit, tile1)) {
            /* It may be impossible to survive at the tile even if it is
             * native. See UTYF_COAST_STRICT */
            ptrans = transporter_for_unit_at(punit, tile1);
          } else {
            ptrans = nullptr;
          }
          if (action_auto_perf_unit_do(AAPC_CITY_GONE, punit,
                                       tile_owner(tile1),
                                       nullptr, nullptr,
                                       tile1, tile_city(tile1), ptrans,
                                       nullptr) != nullptr) {
            moved = TRUE;
          }
          if (moved) {
            notify_player(unit_owner(punit), tile1,
                          E_UNIT_RELOCATED, ftc_server,
                          _("Moved %s out of disbanded city %s "
                            "since it cannot stay on %s."),
                          unit_link(punit), ctl,
                          terrain_name_translation(tile_terrain(pcenter)));
            break;
          }
        }
      }
    } adjc_iterate_end;
    if (!moved) {
      notify_player(unit_owner(punit), unit_tile(punit),
                    E_UNIT_LOST_MISC, ftc_server,
                    _("When %s was disbanded your %s could not "
                      "get out, and it was therefore lost."),
                    ctl,
                    unit_tile_link(punit));
      wipe_unit(punit, ULR_CITY_LOST, nullptr);
    }
  } unit_list_iterate_safe_end;
 
  process_queue = tile_list_new();
  dbv_init(&tile_processed, map_num_tiles());
  for (tile_list_append(process_queue, pcenter); tile_list_size(process_queue) > 0;) {
    struct tile *ptile = tile_list_front(process_queue);
 
    tile_list_pop_front(process_queue);
    dbv_set(&tile_processed, tile_index(ptile));
    adjc_iterate(nmap, ptile, piter) {
      struct city *other_city;
 
      if (dbv_isset(&tile_processed, tile_index(piter))) {
        continue;
      }
      other_city = tile_city(piter);
      if (other_city != nullptr) {
        /* Adjacent tile has a city that may have been part of same channel */
        dbv_set(&tile_processed, tile_index(piter));
        tile_list_append(process_queue, piter);
        unit_list_iterate_safe(piter->units, punit) {
          struct unit_class *pclass = utype_class(punit->utype);
 
          if (!uclass_has_flag(pclass, UCF_BUILD_ANYWHERE)
              && !is_native_tile(punit->utype, piter)
              && !is_city_channel_tile(nmap, pclass, piter, pcenter)) {
            notify_player(unit_owner(punit), unit_tile(punit),
                          E_UNIT_LOST_MISC, ftc_server,
                          _("When %s was disbanded your %s in %s was trapped, "
                            "and it was therefore lost."),
                          ctl,
                          unit_tile_link(punit),
                          city_link(other_city));
            wipe_unit(punit, ULR_CITY_LOST, nullptr);
          }
        } unit_list_iterate_safe_end;
      } else {
        dbv_set(&tile_processed, tile_index(piter));
      }
    } adjc_iterate_end;
  }
 
  dbv_free(&tile_processed);
  tile_list_destroy(process_queue);
 
  if (!city_exist(id)) {
    /* Wiping trapped units caused city to disappear. */
    return;
  }
 
  /* Any remaining supported units are destroyed */
  unit_list_iterate_safe(pcity->units_supported, punit) {
    wipe_unit(punit, ULR_CITY_LOST, nullptr);
  } unit_list_iterate_safe_end;
 
  if (!city_exist(id)) {
    /* Wiping supported units caused city to disappear. */
    return;
  }
 
  trade_routes_iterate_safe(pcity, proute) {
    struct  trade_route *pback = remove_trade_route(pcity, proute,
                                                    TRUE, TRUE);
 
    FC_FREE(proute);
    FC_FREE(pback);
  } trade_routes_iterate_safe_end;
 
  map_clear_border(pcenter);
  city_workers_queue_remove(pcity);
  city_thaw_workers_queue();
  city_refresh_queue_processing();
 
  /* idex_unregister_city() is called in game_remove_city() below */
 
  /* identity_number_release(pcity->id) is *NOT* done! The cities may
   * still be alive in the client, or in the player map. The number of
   * removed cities is small, so the loss is acceptable. */
 
  old_vision = pcity->server.vision;
  pcity->server.vision = nullptr;
  script_server_remove_exported_object(pcity);
  adv_city_free(pcity);
 
  /* Remove city from the map. */
  tile_set_worked(pcenter, nullptr);
 
  /* Reveal units. */
  players_iterate(other_player) {
    if (can_player_see_units_in_city(other_player, pcity)
        || !map_is_known_and_seen(pcenter, other_player, V_MAIN)) {
      continue;
    }
    unit_list_iterate(pcenter->units, punit) {
      if (can_player_see_unit(other_player, punit)) {
        send_unit_info(other_player->connections, punit);
      }
    } unit_list_iterate_end;
  } players_iterate_end;
 
  fc_mutex_allocate(&game.server.mutexes.city_list);
  game_remove_city(&wld, pcity);
  fc_mutex_release(&game.server.mutexes.city_list);
 
  /* Remove any extras that were only there because the city was there. */
  extra_type_iterate(pextra) {
    if (tile_has_extra(pcenter, pextra)
        && !is_native_tile_to_extra(pextra, pcenter)) {
      tile_extra_rm_apply(pcenter, pextra);
    }
  } extra_type_iterate_end;
 
  players_iterate(other_player) {
    if (map_is_known_and_seen(pcenter, other_player, V_MAIN)) {
      reality_check_city(other_player, pcenter);
    } else if (get_player_bonus(other_player, EFT_REVEAL_CITIES) > 0) {
      map_show_tile(other_player, pcenter);
    }
  } players_iterate_end;
 
  conn_list_iterate(game.est_connections, pconn) {
    if (pconn->playing == nullptr && pconn->observer) {
      /* For detached observers we have to send a specific packet. This is
       * a hack necessitated by the private map that exists for players but
       * not observers. */
      dsend_packet_city_remove(pconn, id);
    }
  } conn_list_iterate_end;
 
  if (old_vision != NULL) {
    vision_clear_sight(old_vision);
    vision_free(old_vision);
  }
 
  /* Infrastructures may have changed. */
  send_tile_info(nullptr, pcenter, FALSE);
 
  /* Build a new palace for free if the player lost their capital and
   * savepalace is on. */
  build_free_small_wonders(powner, &had_small_wonders);
 
  /* Update wonder infos. */
  if (had_great_wonders) {
    send_game_info(nullptr);
    /* No need to send to detached connections. */
    send_player_info_c(powner, nullptr);
  } else if (BV_ISSET_ANY(had_small_wonders)) {
    /* No need to send to detached connections. */
    send_player_info_c(powner, nullptr);
  }
 
  if (old_content_citizens != player_content_citizens(powner)
      || old_angry_citizens != player_angry_citizens(powner)) {
    /* We crossed the EFT_EMPIRE_SIZE_* effects, we have to refresh all
     * cities for the player. */
    city_refresh_for_player(powner);
  }
 
  sync_cities();
 
  /* At least sentried helicopters need to go idle, maybe others.
   * In alien ruleset, city center might have provided water source
   * for adjacent tile. */
  tile_change_side_effects(pcenter, FALSE);
}
 
/************************************************************************/
bool unit_conquer_city(struct unit *punit, struct city *pcity)
{
  bool try_civil_war = FALSE;
  bool city_remains;
  int coins;
  struct player *pplayer = unit_owner(punit);
  struct player *cplayer = city_owner(pcity);
#ifndef FREECIV_NDEBUG
  const struct unit_type *utype = unit_type_get(punit);
#endif
 
  /* If not at war, may peacefully enter city. */
  fc_assert_ret_val_msg(pplayers_at_war(pplayer, cplayer), FALSE,
                        "Can't conquer city during peace.");
 
  /* If we cannot occupy the city, this unit entering will not trigger
   * effects below. */
  fc_assert_ret_val_msg(unit_can_take_over(punit)
                        || utype_can_do_action_result(utype, ACTRES_PARADROP_CONQUER)
                        || utype_can_do_action_result(utype, ACTRES_TELEPORT_CONQUER),
                        FALSE, "Bad unit for city occupation.");
 
  /* A transported unit trying to conquer a city should already have been
   * unloaded. */
  fc_assert_ret_val_msg(punit->transporter == nullptr, FALSE,
                        "Can't conquer city while transported.");
 
  /* Okay, we're at war - invader captures/destroys city... */
 
  /* If a capital is captured, then spark off a civil war
   *  - Kris Bubendorfer
   *  Also check spaceships --dwp */
 
  if (is_capital(pcity)
      && (cplayer->spaceship.state == SSHIP_STARTED
          || cplayer->spaceship.state == SSHIP_LAUNCHED)) {
    spaceship_lost(cplayer);
  }
 
  if (is_capital(pcity)
      && civil_war_possible(cplayer, TRUE, TRUE)
      && normal_player_count() < MAX_NUM_PLAYERS
      && civil_war_triggered(cplayer)) {
    try_civil_war = TRUE;
  }
 
  /*
   * We later remove a citizen. Lets check if we can save this since
   * the city will be destroyed.
   */
  if (city_size_get(pcity) <= 1) {
    int saved_id = pcity->id;
 
    notify_player(pplayer, city_tile(pcity), E_CITY_CONQUERED, ftc_server,
                  _("You destroy %s completely."),
                  city_tile_link(pcity));
    notify_player(cplayer, city_tile(pcity), E_CITY_LOST, ftc_server,
                  _("%s has been destroyed by %s."),
                  city_tile_link(pcity), player_name(pplayer));
    script_server_signal_emit("city_destroyed", pcity, cplayer, pplayer);
 
    /* We can't be sure of city existence after running some script */
    if (city_exist(saved_id)) {
      remove_city(pcity);
    }
 
    if (try_civil_war) {
      (void) civil_war(cplayer);
    }
    return TRUE;
  }
 
  coins = cplayer->economic.gold;
  coins = MIN(coins,
              fc_rand((coins / 20) + 1)
              + (coins * (city_size_get(pcity))) / 200);
  pplayer->economic.gold += coins;
  cplayer->economic.gold -= coins;
  send_player_info_c(pplayer, pplayer->connections);
  send_player_info_c(cplayer, cplayer->connections);
  if (pcity->original != pplayer) {
    if (coins > 0) {
      notify_player(pplayer, city_tile(pcity), E_CITY_CONQUERED, ftc_server,
                    PL_("You conquer %s; your lootings accumulate"
                        " to %d gold!",
                        "You conquer %s; your lootings accumulate"
                        " to %d gold!", coins),
                    city_link(pcity),
                    coins);
      notify_player(cplayer, city_tile(pcity), E_CITY_LOST, ftc_server,
                    PL_("%s conquered %s and looted %d gold"
                        " from the city.",
                        "%s conquered %s and looted %d gold"
                        " from the city.", coins),
                    player_name(pplayer),
                    city_link(pcity),
                    coins);
    } else {
      notify_player(pplayer, city_tile(pcity), E_CITY_CONQUERED, ftc_server,
                    _("You conquer %s."),
                    city_link(pcity));
      notify_player(cplayer, city_tile(pcity), E_CITY_LOST, ftc_server,
                    _("%s conquered %s."),
                    player_name(pplayer),
                    city_link(pcity));
    }
  } else {
    if (coins > 0) {
      notify_player(pplayer, city_tile(pcity), E_CITY_CONQUERED, ftc_server,
                    PL_("You have liberated %s!"
                        " Lootings accumulate to %d gold.",
                        "You have liberated %s!"
                        " Lootings accumulate to %d gold.", coins),
                    city_link(pcity),
                    coins);
      notify_player(cplayer, city_tile(pcity), E_CITY_LOST, ftc_server,
                    PL_("%s liberated %s and looted %d gold"
                        " from the city.",
                        "%s liberated %s and looted %d gold"
                        " from the city.", coins),
                    player_name(pplayer),
                    city_link(pcity),
                    coins);
    } else {
      notify_player(pplayer, city_tile(pcity), E_CITY_CONQUERED, ftc_server,
                    _("You have liberated %s!"),
                    city_link(pcity));
      notify_player(cplayer, city_tile(pcity), E_CITY_LOST, ftc_server,
                    _("%s liberated %s."),
                    player_name(pplayer),
                    city_link(pcity));
    }
  }
 
  if (fc_rand(100) <  get_unit_bonus(punit, EFT_CONQUEST_TECH_PCT)) {
    /* Just try to steal. Ignore failures to get tech */
    steal_a_tech(pplayer, cplayer, A_UNSET);
  }
 
  /* We transfer the city first so that it is in a consistent state when
   * the size is reduced. */
  /* FIXME: maybe it should be a ruleset option whether barbarians get
   * free buildings such as palaces? */
  city_remains = transfer_city(pplayer, pcity, 0, TRUE, TRUE, TRUE,
                               !is_barbarian(pplayer));
 
  if (city_remains) {
    /* Reduce size should not destroy this city */
    fc_assert(city_size_get(pcity) > 1);
    city_reduce_size(pcity, 1, pplayer, "conquest");
  }
 
  if (try_civil_war) {
    (void) civil_war(cplayer);
  }
 
  if (city_remains) {
    script_server_signal_emit("city_transferred", pcity, cplayer, pplayer,
                              "conquest");
    script_server_signal_emit("city_lost", pcity, cplayer, pplayer);
  }
 
  return TRUE;
}
 
/************************************************************************/
static int city_citywalls_gfx(const struct city *pcity)
{
  int walls = get_city_bonus(pcity, EFT_VISIBLE_WALLS);
 
  return walls > 0 ? walls : 0;
}
 
/************************************************************************/
bool send_city_suppression(bool now)
{
  bool formerly = send_city_suppressed;
 
  send_city_suppressed = now;
  return formerly;
}
 
/************************************************************************/
static void package_dumb_city(struct player *pplayer, struct tile *ptile,
                              struct packet_city_short_info *packet)
{
  struct vision_site *pdcity = map_get_player_city(ptile, pplayer);
 
  packet->id = pdcity->identity;
  packet->owner = player_number(vision_site_owner(pdcity));
 
  if (pdcity->original != NULL) {
    packet->original = player_number(pdcity->original);
  } else {
    packet->original = MAX_NUM_PLAYER_SLOTS;
  }
 
  packet->tile = tile_index(ptile);
  if (pdcity->name == nullptr) {
    packet->name[0] = '\0';
  } else {
    sz_strlcpy(packet->name, pdcity->name);
  }
 
  packet->size = vision_site_size_get(pdcity);
 
  packet->occupied = pdcity->occupied;
  packet->walls = pdcity->walls;
  packet->style = pdcity->style;
  packet->city_image = pdcity->city_image;
  packet->capital = pdcity->capital;
 
  packet->happy = pdcity->happy;
  packet->unhappy = pdcity->unhappy;
 
  packet->improvements = pdcity->improvements;
}
 
/************************************************************************/
void refresh_dumb_city(struct city *pcity)
{
  players_iterate(pplayer) {
    if (player_can_see_city_externals(pplayer, pcity)) {
      if (update_dumb_city(pplayer, pcity)) {
        struct packet_city_short_info packet;
 
        if (city_owner(pcity) != pplayer) {
          /* Don't send the short_city information to someone who can see
           * city's internals. Doing so would really confuse the client. */
          package_dumb_city(pplayer, pcity->tile, &packet);
          lsend_packet_city_short_info(pplayer->connections, &packet);
        }
      }
    }
  } players_iterate_end;
 
  /* Don't send to non-player observers since they don't have 'dumb city'
   * information. */
}
 
/************************************************************************/
void broadcast_city_info(struct city *pcity)
{
  struct packet_city_info packet;
  struct packet_city_nationalities nat_packet;
  struct packet_city_rally_point rally_packet;
  struct packet_web_city_info_addition web_packet;
  struct packet_city_short_info sc_pack;
  struct player *powner = city_owner(pcity);
  struct trade_route_packet_list *routes;
  struct packet_web_city_info_addition *webp_ptr;
 
  /* Send to everyone who can see the city. */
 
  if (pcity->server.needs_arrange != CNA_NOT) {
    /* Send city only when it's in sane state.
     * If it's not, it will be sent to everyone once
     * rearrangement has been finished. */
    pcity->server.needs_arrange = CNA_BROADCAST_PENDING;
 
    return;
  }
 
  if (any_web_conns()) {
    webp_ptr = &web_packet;
  } else {
    webp_ptr = nullptr;
  }
 
  routes = trade_route_packet_list_new();
  package_city(pcity, &packet, &nat_packet, &rally_packet,
               webp_ptr, routes, FALSE);
 
  players_iterate(pplayer) {
    if (!send_city_suppressed || pplayer != powner) {
      if (can_player_see_city_internals(pplayer, pcity)) {
        update_dumb_city(pplayer, pcity);
        packet.original = city_original_owner(pcity, pplayer);
        lsend_packet_city_info(pplayer->connections, &packet, FALSE);
        lsend_packet_city_nationalities(pplayer->connections, &nat_packet, FALSE);
        lsend_packet_city_rally_point(pplayer->connections, &rally_packet, FALSE);
        web_lsend_packet(city_info_addition, pplayer->connections,
                         webp_ptr, FALSE);
        trade_route_packet_list_iterate(routes, route_packet) {
          lsend_packet_trade_route_info(pplayer->connections, route_packet);
        } trade_route_packet_list_iterate_end;
      } else if (player_can_see_city_externals(pplayer, pcity)) {
        reality_check_city(pplayer, pcity->tile);
        update_dumb_city(pplayer, pcity);
        package_dumb_city(pplayer, pcity->tile, &sc_pack);
        lsend_packet_city_short_info(pplayer->connections, &sc_pack);
      }
    }
  } players_iterate_end;
 
  /* Send to global observers. */
  packet.original = city_original_owner(pcity, nullptr);
  conn_list_iterate(game.est_connections, pconn) {
    if (conn_is_global_observer(pconn)) {
      send_packet_city_info(pconn, &packet, FALSE);
      send_packet_city_nationalities(pconn, &nat_packet, FALSE);
      send_packet_city_rally_point(pconn, &rally_packet, FALSE);
      web_send_packet(city_info_addition, pconn, webp_ptr, FALSE);
    }
  } conn_list_iterate_end;
 
  trade_route_packet_list_iterate(routes, route_packet) {
    FC_FREE(route_packet);
  } trade_route_packet_list_iterate_end;
  trade_route_packet_list_destroy(routes);
}
 
/************************************************************************/
void send_all_known_cities(struct conn_list *dest)
{
  conn_list_do_buffer(dest);
  conn_list_iterate(dest, pconn) {
    struct player *pplayer = pconn->playing;
 
    if (!pplayer && !pconn->observer) {
      continue;
    }
    whole_map_iterate(&(wld.map), ptile) {
      if (pplayer == nullptr
          || map_get_player_site(ptile, pplayer) != nullptr) {
        send_city_info_at_tile(pplayer, pconn->self, nullptr, ptile);
      }
    } whole_map_iterate_end;
  }
  conn_list_iterate_end;
  conn_list_do_unbuffer(dest);
  flush_packets();
}
 
/************************************************************************/
void send_player_cities(struct player *pplayer)
{
  city_list_iterate(pplayer->cities, pcity) {
    if (city_refresh(pcity)) {
      log_error("%s radius changed while sending to player.",
                city_name_get(pcity));
 
      /* Make sure that no workers in illegal position outside radius. */
      auto_arrange_workers(pcity);
    }
    send_city_info(pplayer, pcity);
  }
  city_list_iterate_end;
}
 
/************************************************************************/
void send_city_info(struct player *dest, struct city *pcity)
{
  struct player *powner = city_owner(pcity);
 
  if (S_S_RUNNING != server_state() && S_S_OVER != server_state()) {
    return;
  }
 
  if (dest == powner && send_city_suppressed) {
    return;
  }
 
  if (!dest || dest == powner) {
    pcity->server.synced = TRUE;
  }
 
  if (!dest) {
    broadcast_city_info(pcity);
  } else {
    send_city_info_at_tile(dest, dest->connections, pcity, pcity->tile);
  }
 
  /* Sending counters */
  city_counters_refresh(pcity);
 
  if (game.info.team_pooled_research
      && player_list_size(team_members(powner->team)) > 1) {
    /* We want to send the new total bulbs production of the team. */
    send_research_info(research_get(powner), nullptr);
  }
}
 
/************************************************************************/
void send_city_info_at_tile(struct player *pviewer, struct conn_list *dest,
                            struct city *pcity, struct tile *ptile)
{
  struct packet_city_info packet;
  struct packet_city_nationalities nat_packet;
  struct packet_city_rally_point rally_packet;
  struct packet_web_city_info_addition web_packet;
  struct packet_city_short_info sc_pack;
  struct player *powner = nullptr;
  struct trade_route_packet_list *routes = nullptr;
  struct packet_web_city_info_addition *webp_ptr;
 
  if (!pcity) {
    pcity = tile_city(ptile);
  }
  if (pcity != nullptr && pcity->server.needs_arrange != CNA_NOT) {
    pcity->server.needs_arrange = CNA_BROADCAST_PENDING;
 
    return;
  }
  if (pcity) {
    powner = city_owner(pcity);
  }
 
  if (any_web_conns()) {
    webp_ptr = &web_packet;
  } else {
    webp_ptr = nullptr;
  }
 
  if (powner != nullptr && powner == pviewer) {
    /* Send info to owner */
    /* This case implies powner non-nullptr which means pcity non-nullptr */
    if (!send_city_suppressed) {
      /* Wait that city has been rearranged, if it's currently
       * not in a sane state. */
 
      routes = trade_route_packet_list_new();
 
      /* Send all info to the owner */
      update_dumb_city(powner, pcity);
      package_city(pcity, &packet, &nat_packet, &rally_packet,
                   webp_ptr, routes, FALSE);
      packet.original = city_original_owner(pcity, pviewer);
      lsend_packet_city_info(dest, &packet, FALSE);
      lsend_packet_city_nationalities(dest, &nat_packet, FALSE);
      lsend_packet_city_rally_point(dest, &rally_packet, FALSE);
      web_lsend_packet(city_info_addition, dest, webp_ptr, FALSE);
      trade_route_packet_list_iterate(routes, route_packet) {
        lsend_packet_trade_route_info(dest, route_packet);
      } trade_route_packet_list_iterate_end;
      if (dest == powner->connections) {
        /* HACK: send also a copy to global observers. */
        packet.original = city_original_owner(pcity, nullptr);
        conn_list_iterate(game.est_connections, pconn) {
          if (conn_is_global_observer(pconn)) {
            send_packet_city_info(pconn, &packet, FALSE);
            trade_route_packet_list_iterate(routes, route_packet) {
              send_packet_trade_route_info(pconn, route_packet);
            } trade_route_packet_list_iterate_end;
          }
        } conn_list_iterate_end;
      }
    }
  } else {
    /* Send info to non-owner */
    if (!pviewer) {  /* Observer */
      if (pcity) {
        routes = trade_route_packet_list_new();
 
        /* Should be dumb_city info? */
        package_city(pcity, &packet, &nat_packet, &rally_packet,
                     webp_ptr, routes, FALSE);
        lsend_packet_city_info(dest, &packet, FALSE);
        lsend_packet_city_nationalities(dest, &nat_packet, FALSE);
        lsend_packet_city_rally_point(dest, &rally_packet, FALSE);
        web_lsend_packet(city_info_addition, dest, webp_ptr, FALSE);
        trade_route_packet_list_iterate(routes, route_packet) {
          lsend_packet_trade_route_info(dest, route_packet);
        } trade_route_packet_list_iterate_end;
      }
    } else {
      if (map_is_known_and_seen(ptile, pviewer, V_MAIN)) {
        if (pcity) {  /* It's there and we see it; update and send */
          update_dumb_city(pviewer, pcity);
          package_dumb_city(pviewer, ptile, &sc_pack);
          lsend_packet_city_short_info(dest, &sc_pack);
        }
      } else {        /* Not seen; send old info */
        if (map_is_known(ptile, pviewer)
            && map_get_player_site(ptile, pviewer) != nullptr) {
          package_dumb_city(pviewer, ptile, &sc_pack);
          lsend_packet_city_short_info(dest, &sc_pack);
        }
      }
    }
  }
 
  if (routes != nullptr) {
    trade_route_packet_list_iterate(routes, route_packet) {
      FC_FREE(route_packet);
    } trade_route_packet_list_iterate_end;
    trade_route_packet_list_destroy(routes);
  }
}
 
/************************************************************************/
void package_city(struct city *pcity, struct packet_city_info *packet,
                  struct packet_city_nationalities *nat_packet,
                  struct packet_city_rally_point *rally_packet,
                  struct packet_web_city_info_addition *web_packet,
                  struct trade_route_packet_list *routes,
                  bool dipl_invest)
{
  int i;
  int ppl = 0; /* Counter of citizens for sanity check */
 
  fc_assert(!pcity->server.needs_arrange);
 
  packet->id = pcity->id;
  packet->owner = player_number(city_owner(pcity));
 
  packet->tile = tile_index(city_tile(pcity));
  sz_strlcpy(packet->name, city_name_get(pcity));
 
  packet->size = city_size_get(pcity);
  for (i = 0; i < FEELING_LAST; i++) {
    packet->ppl_happy[i] = pcity->feel[CITIZEN_HAPPY][i];
    packet->ppl_content[i] = pcity->feel[CITIZEN_CONTENT][i];
    packet->ppl_unhappy[i] = pcity->feel[CITIZEN_UNHAPPY][i];
    packet->ppl_angry[i] = pcity->feel[CITIZEN_ANGRY][i];
    if (i == 0) {
      ppl += packet->ppl_happy[i];
      ppl += packet->ppl_content[i];
      ppl += packet->ppl_unhappy[i];
      ppl += packet->ppl_angry[i];
    }
  }
  /* The number of data in specialists[] array */
  packet->specialists_size = specialist_count();
  specialist_type_iterate(sp) {
    packet->specialists[sp] = pcity->specialists[sp];
    if (is_normal_specialist_id(sp)) {
      ppl += packet->specialists[sp];
    }
  } specialist_type_iterate_end;
 
  /* The nationality of the citizens. */
  nat_packet->id = pcity->id;
  nat_packet->nationalities_count = 0;
  if (game.info.citizen_nationality) {
    int cit = 0;
 
    player_slots_iterate(pslot) {
      citizens nationality = citizens_nation_get(pcity, pslot);
 
      if (nationality != 0) {
        /* This player should exist! */
        fc_assert(player_slot_get_player(pslot) != nullptr);
 
        nat_packet->nation_id[nat_packet->nationalities_count]
          = player_slot_index(pslot);
        nat_packet->nation_citizens[nat_packet->nationalities_count]
          = nationality;
        nat_packet->nationalities_count++;
 
        cit += nationality;
      }
    } player_slots_iterate_end;
 
    fc_assert(cit == packet->size);
  }
 
  packet->history = pcity->history;
  packet->culture = city_culture(pcity);
  packet->buy_cost = city_production_buy_gold_cost(pcity);
 
  if (packet->size != ppl) {
    static bool recursion = FALSE;
 
    if (recursion) {
      /* Recursion didn't help. Do not enter infinite recursive loop.
       * Package city as it is. */
      log_error("Failed to fix inconsistent city size.");
      recursion = FALSE;
    } else {
      /* Note: If you get this error and try to debug the cause, you may find
       *       using check_city_feelings() in some key points useful. */
      /* Have this as an fc_assert() first, so one can use '-F' to caught
       * these in debugger. */
      fc_assert(packet->size == ppl);
 
      /* In all builds have an error message shown. */
      log_error("City size %d, citizen count %d for %s",
                packet->size, ppl, city_name_get(pcity));
 
      /* Try to fix */
      city_refresh(pcity);
      auto_arrange_workers(pcity);
 
      /* And repackage */
      recursion = TRUE;
      package_city(pcity, packet, nat_packet, rally_packet,
                   web_packet, routes, dipl_invest);
      recursion = FALSE;
 
      return;
    }
  }
 
  packet->city_radius_sq = pcity->city_radius_sq;
 
  i = 0;
  trade_routes_iterate(pcity, proute) {
    struct packet_trade_route_info *tri_packet
      = fc_malloc(sizeof(struct packet_trade_route_info));
 
    tri_packet->city = pcity->id;
    tri_packet->index = i;
    tri_packet->partner = proute->partner;
    tri_packet->value = proute->value;
    tri_packet->direction = proute->dir;
    tri_packet->goods = goods_number(proute->goods);
 
    trade_route_packet_list_append(routes, tri_packet);
 
    i++;
  } trade_routes_iterate_end;
 
  packet->trade_route_count = i;
 
  output_type_iterate(o) {
    packet->surplus[o] = pcity->surplus[o];
    packet->waste[o] = pcity->waste[o];
    packet->unhappy_penalty[o] = pcity->unhappy_penalty[o];
    packet->prod[o] = pcity->prod[o];
    packet->citizen_base[o] = pcity->citizen_base[o];
    packet->usage[o] = pcity->usage[o];
  } output_type_iterate_end;
 
  packet->food_stock = pcity->food_stock;
  packet->shield_stock = pcity->shield_stock;
  packet->pollution = pcity->pollution;
  packet->illness_trade = pcity->illness_trade;
  packet->city_options = pcity->city_options;
  packet->wl_cb = pcity->wlcb;
 
  if (!dipl_invest) {
    packet->acquire_type = pcity->acquire_t;
  } else {
    /* Dummy value */
    packet->acquire_type = CACQ_CONQUEST;
  }
 
  packet->production_kind = pcity->production.kind;
  packet->production_value = universal_number(&pcity->production);
 
  packet->turn_last_built = pcity->turn_last_built;
  packet->turn_founded = pcity->turn_founded;
 
  packet->changed_from_kind = pcity->changed_from.kind;
  packet->changed_from_value = universal_number(&pcity->changed_from);
 
  packet->before_change_shields = pcity->before_change_shields;
  packet->disbanded_shields = pcity->disbanded_shields;
  packet->caravan_shields = pcity->caravan_shields;
  packet->last_turns_shield_surplus = pcity->last_turns_shield_surplus;
 
  worklist_copy(&packet->worklist, &pcity->worklist);
  packet->diplomat_investigate = dipl_invest;
 
  packet->airlift = pcity->airlift;
  packet->did_buy = pcity->did_buy;
  packet->did_sell = pcity->did_sell;
  packet->was_happy = pcity->was_happy;
  packet->had_famine = pcity->had_famine;
 
  packet->anarchy = pcity->anarchy;
  packet->rapture = pcity->rapture;
 
  packet->walls = city_citywalls_gfx(pcity);
  packet->style = pcity->style;
  packet->city_image = get_city_bonus(pcity, EFT_CITY_IMAGE);
  packet->capital = pcity->capital;
  packet->steal = pcity->steal;
 
  rally_packet->id = pcity->id;
  rally_packet->length = pcity->rally_point.length;
  rally_packet->persistent = pcity->rally_point.persistent;
  rally_packet->vigilant = pcity->rally_point.vigilant;
  if (pcity->rally_point.length) {
    memcpy(rally_packet->orders, pcity->rally_point.orders,
           pcity->rally_point.length * sizeof(struct unit_order));
  }
 
  BV_CLR_ALL(packet->improvements);
  improvement_iterate(pimprove) {
    if (city_has_building(pcity, pimprove)) {
      BV_SET(packet->improvements, improvement_index(pimprove));
    }
  } improvement_iterate_end;
 
#ifdef FREECIV_WEB
  if (web_packet != nullptr) {
    struct tile *pcenter = city_tile(pcity);
    const struct civ_map *nmap = &(wld.map);
 
    BV_CLR_ALL(web_packet->can_build_unit);
    BV_CLR_ALL(web_packet->can_build_improvement);
 
    web_packet->id = pcity->id;
 
    if (pcity->cm_parameter != nullptr) {
      web_packet->cma_enabled = TRUE;
      cm_copy_parameter(&web_packet->cm_parameter, pcity->cm_parameter);
    } else {
      web_packet->cma_enabled = FALSE;
      memset(&web_packet->cm_parameter, 0, sizeof(web_packet->cm_parameter));
    }
 
    web_packet->granary_size = city_granary_size(city_size_get(pcity));
    web_packet->granary_turns = city_turns_to_grow(pcity);
 
    improvement_iterate(pimprove) {
      if (can_city_build_improvement_now(pcity, pimprove, RPT_CERTAIN)) {
        BV_SET(web_packet->can_build_improvement, improvement_index(pimprove));
      }
    } improvement_iterate_end;
 
    unit_type_iterate(punittype) {
      if (can_city_build_unit_now(nmap, pcity, punittype, RPT_CERTAIN)) {
        BV_SET(web_packet->can_build_unit, utype_index(punittype));
      }
    } unit_type_iterate_end;
 
    i = 0;
    city_tile_iterate(nmap, city_map_radius_sq_get(pcity), pcenter, ptile) {
      web_packet->output_food[i] = city_tile_output_now(pcity, ptile, O_FOOD);
      web_packet->output_shield[i] = city_tile_output_now(pcity, ptile, O_SHIELD);
      web_packet->output_trade[i] = city_tile_output_now(pcity, ptile, O_TRADE);
 
      i++;
    } city_tile_iterate_end;
  }
#endif /* FREECIV_WEB */
}
 
/************************************************************************/
bool update_dumb_city(struct player *pplayer, struct city *pcity)
{
  bv_imprs improvements;
  struct tile *pcenter = city_tile(pcity);
  struct vision_site *pdcity = map_get_player_city(pcenter, pplayer);
  /* pcity->client.occupied isn't used at the server, so we go straight to
   * the unit list to check the occupied status. */
  bool occupied = (unit_list_size(pcenter->units) > 0);
  int walls = city_citywalls_gfx(pcity);
  bool happy = city_happy(pcity);
  bool unhappy = city_unhappy(pcity);
  int style = pcity->style;
  int city_image = get_city_bonus(pcity, EFT_CITY_IMAGE);
  enum capital_type capital = pcity->capital;
 
  /* Only someone knowing the tile should ever know a city on it. */
  fc_assert(map_is_known(pcenter, pplayer));
 
  BV_CLR_ALL(improvements);
  improvement_iterate(pimprove) {
    if (is_improvement_visible(pimprove)
     && city_has_building(pcity, pimprove)) {
      BV_SET(improvements, improvement_index(pimprove));
    }
  } improvement_iterate_end;
 
  if (pdcity == nullptr) {
    pdcity = vision_site_new_from_city(pcity, pplayer);
    change_playertile_site(map_get_player_tile(pcenter, pplayer), pdcity);
  } else if (pdcity->location != pcenter) {
    log_error("Trying to update bad city (wrong location) "
              "at %i,%i for player %s",
              TILE_XY(pcity->tile), player_name(pplayer));
    fc_assert(pdcity->location == pcenter);
    pdcity->location = pcenter;   /* ?? */
  } else if (pdcity->identity != pcity->id) {
    log_error("Trying to update old city (wrong identity) "
              "at %i,%i for player %s",
              TILE_XY(city_tile(pcity)), player_name(pplayer));
    fc_assert(pdcity->identity == pcity->id);
    pdcity->identity = pcity->id;   /* ?? */
  } else if (pdcity->occupied == occupied
             && pdcity->walls == walls
             && pdcity->happy == happy
             && pdcity->unhappy == unhappy
             && pdcity->style == style
             && pdcity->city_image == city_image
             && pdcity->capital == capital
             && BV_ARE_EQUAL(pdcity->improvements, improvements)
             && vision_site_size_get(pdcity) == city_size_get(pcity)
             && vision_site_owner(pdcity) == city_owner(pcity)
             && (pdcity->name && !strcmp(pdcity->name, city_name_get(pcity)))) {
    return FALSE;
  }
 
  vision_site_update_from_city(pdcity, pcity, pplayer);
  pdcity->occupied = occupied;
  pdcity->walls = walls;
  pdcity->style = style;
  pdcity->city_image = city_image;
  pdcity->capital = capital;
  pdcity->happy = happy;
  pdcity->unhappy = unhappy;
  pdcity->improvements = improvements;
 
  return TRUE;
}
 
/************************************************************************/
void reality_check_city(struct player *pplayer, struct tile *ptile)
{
  struct vision_site *pdcity = map_get_player_city(ptile, pplayer);
 
  if (pdcity) {
    struct city *pcity = tile_city(ptile);
 
    if (!pcity || pcity->id != pdcity->identity) {
      struct player_tile *playtile = map_get_player_tile(ptile, pplayer);
 
      dlsend_packet_city_remove(pplayer->connections, pdcity->identity);
      fc_assert_ret(playtile->site == pdcity);
      playtile->site = nullptr;
      vision_site_destroy(pdcity);
    }
  }
}
 
/************************************************************************/
void remove_dumb_city(struct player *pplayer, struct tile *ptile)
{
  struct vision_site *pdcity = map_get_player_city(ptile, pplayer);
 
  if (pdcity) {
    struct player_tile *playtile = map_get_player_tile(ptile, pplayer);
 
    dlsend_packet_city_remove(pplayer->connections, pdcity->identity);
    fc_assert_ret(playtile->site == pdcity);
    playtile->site = nullptr;
    vision_site_destroy(pdcity);
  }
}
 
/************************************************************************/
static void announce_trade_route_removal(struct city *pc1, struct city *pc2,
                                         bool source_gone)
{
  struct player *plr1 = city_owner(pc1);
  struct player *plr2 = city_owner(pc2);
  char city1_link[MAX_LEN_LINK];
  char city2_link[MAX_LEN_LINK];
 
  sz_strlcpy(city1_link, city_link(pc1));
  sz_strlcpy(city2_link, city_link(pc2));
 
  if (plr1 == plr2) {
    if (source_gone) {
      notify_player(plr2, city_tile(pc2),
                    E_CARAVAN_ACTION, ftc_server,
                    _("Trade between %s and %s lost along with city."),
                    city1_link, city2_link);
    } else {
      notify_player(plr1, city_tile(pc1),
                    E_CARAVAN_ACTION, ftc_server,
                    _("Trade route between %s and %s canceled."),
                    city1_link, city2_link);
    }
  } else {
    if (source_gone) {
      notify_player(plr2, city_tile(pc2),
                    E_CARAVAN_ACTION, ftc_server,
                    /* TRANS: "...between Spanish city Madrid and Paris..." */
                    _("Trade between %s city %s and %s lost along with "
                      "their city."),
                    nation_adjective_for_player(plr1), city1_link, city2_link);
      /* It's implicit to removed city's owner that that city no longer
       * has trade routes, so say nothing in that case */
    } else {
      notify_player(plr2, city_tile(pc2),
                    E_CARAVAN_ACTION, ftc_server,
                    _("Sorry, the %s canceled the trade route "
                      "from %s to your city %s."),
                    nation_plural_for_player(plr1), city1_link, city2_link);
      notify_player(plr1, city_tile(pc1),
                    E_CARAVAN_ACTION, ftc_server,
                    /* TRANS: "...from Paris to Spanish city Madrid." */
                    _("We canceled the trade route "
                      "from %s to %s city %s."),
                    city1_link, nation_adjective_for_player(plr2), city2_link);
    }
  }
}
 
/************************************************************************/
struct trade_route *remove_trade_route(struct city *pc1,
                                       struct trade_route *proute,
                                       bool announce, bool source_gone)
{
  struct city *pc2 = game_city_by_number(proute->partner);
  struct trade_route *back_route = nullptr;
 
  fc_assert_ret_val(pc1 && proute, nullptr);
 
  trade_route_list_remove(pc1->routes, proute);
 
  if (pc2 != nullptr) {
    trade_routes_iterate(pc2, pback) {
      if (pc1->id == pback->partner) {
        back_route = pback;
      }
    } trade_routes_iterate_end;
 
    if (back_route != nullptr) {
      trade_route_list_remove(pc2->routes, back_route);
    }
 
    if (announce) {
      announce_trade_route_removal(pc1, pc2, source_gone);
 
      city_refresh(pc2);
      send_city_info(city_owner(pc2), pc2);
    }
  }
 
  return back_route;
}
 
/**********************************************************************/
bool city_illness_strike(struct city *pcity)
{
  notify_player(city_owner(pcity), city_tile(pcity), E_CITY_PLAGUE,
                ftc_server,
                _("%s has been struck by a plague! Population lost!"),
                city_link(pcity));
  if (city_reduce_size(pcity, 1, nullptr, "plague")) {
    pcity->turn_plague = game.info.turn;
 
    /* Recalculate illness */
    pcity->server.illness = city_illness_calc(pcity, nullptr, nullptr,
                                              &(pcity->illness_trade),
                                              nullptr);
 
    return TRUE;
  }
 
  return FALSE;
}
 
/************************************************************************/
void do_sell_building(struct player *pplayer, struct city *pcity,
                      struct impr_type *pimprove, const char *reason)
{
  if (can_city_sell_building(pcity, pimprove)) {
    pplayer->economic.gold += impr_sell_gold(pimprove);
    building_lost(pcity, pimprove, reason, nullptr);
  }
}
 
/************************************************************************/
struct city
*build_or_move_building(struct city *pcity, struct impr_type *pimprove,
                        struct player **oldcity_owner)
{
  struct city *oldcity = nullptr;
 
  fc_assert_ret_val(!city_has_building(pcity, pimprove), nullptr);
 
  if (is_great_wonder(pimprove)) {
    if (!(oldcity = city_from_great_wonder(pimprove))) {
      oldcity = pcity;
    }
    *oldcity_owner = city_owner(oldcity);
  } else if (is_small_wonder(pimprove)) {
    if (!(oldcity
          = city_from_small_wonder(city_owner(pcity), pimprove))) {
      oldcity = pcity;
    }
  }
  if (oldcity && oldcity != pcity) {
    city_remove_improvement(oldcity, pimprove);
    city_add_improvement_with_gov_notice(pcity, pimprove,
                                         _("Moving %s"));
  } else {
    city_add_improvement_with_gov_notice(pcity, pimprove,
                                         _("Acquiring %s"));
  }
 
  return oldcity;
}
 
/************************************************************************/
bool building_removed(struct city *pcity, const struct impr_type *pimprove,
                      const char *reason, struct unit *destroyer)
{
  int backup = pcity->id;
 
  city_remove_improvement(pcity, pimprove);
 
  script_server_signal_emit("building_lost", pcity, pimprove, reason,
                            destroyer);
 
  return city_exist(backup);
}
 
/************************************************************************/
void building_lost(struct city *pcity, const struct impr_type *pimprove,
                   const char *reason, struct unit *destroyer)
{
  struct player *owner = city_owner(pcity);
  bool was_capital = is_capital(pcity);
  bool city_remains;
 
  city_remains = building_removed(pcity, pimprove, reason, destroyer);
 
  if ((was_capital && (!city_remains || !is_capital(pcity)))
      && (owner->spaceship.state == SSHIP_STARTED
          || owner->spaceship.state == SSHIP_LAUNCHED)) {
    /* If the capital was lost (by destruction of the palace) production on
     * the spaceship is lost. */
    spaceship_lost(owner);
  }
 
  if (city_remains) {
    /* Update city; influence of effects (buildings, ...) on unit upkeep */
    if (city_refresh(pcity)) {
      auto_arrange_workers(pcity);
    }
 
    /* Re-update the city's visible area. This updates fog if the vision
     * range increases or decreases. */
    city_refresh_vision(pcity);
  }
}
 
/************************************************************************/
void update_unit_upkeep(struct unit *punit, int free_uk[O_LAST])
{
  bool update = FALSE;
  int cost;
 
  output_type_iterate(o) {
    cost = unit_upkeep_cost(punit, o);
    if (cost > 0) {
      if (free_uk[o] > cost) {
        free_uk[o] -= cost;
        cost = 0;
      } else {
        cost -= free_uk[o];
        free_uk[o] = 0;
      }
    }
 
    if (cost != punit->upkeep[o]) {
      update = TRUE;
      punit->upkeep[o] = cost;
    }
  } output_type_iterate_end;
 
  if (update) {
    /* Update unit information to the player and global observers. */
    send_unit_info(nullptr, punit);
  }
}
 
/************************************************************************/
void city_units_upkeep(const struct city *pcity)
{
  int free_uk[O_LAST];
 
  if (!pcity || !pcity->units_supported
      || unit_list_size(pcity->units_supported) < 1) {
    return;
  }
 
  output_type_iterate(o) {
    free_uk[o] = get_city_output_bonus(pcity, get_output_type(o),
                                       EFT_UNIT_UPKEEP_FREE_PER_CITY);
  } output_type_iterate_end;
 
  /* Save the upkeep for all units in the corresponding punit struct */
  unit_list_iterate(pcity->units_supported, punit) {
    update_unit_upkeep(punit, free_uk);
  } unit_list_iterate_end;
}
 
/************************************************************************/
void change_build_target(struct player *pplayer, struct city *pcity,
                         struct universal *target,
                         enum event_type event)
{
  const char *name;
  const char *source;
 
  /* If the city is already building this thing, don't do anything */
  if (are_universals_equal(&pcity->production, target)) {
    return;
  }
 
  /* Is the city no longer building a wonder? */
  if (VUT_IMPROVEMENT == pcity->production.kind
      && is_great_wonder(pcity->production.value.building)
      && event != E_IMP_AUTO
      && event != E_WORKLIST) {
    /* If the build target is changed because of an advisor's suggestion or
     * because the worklist advances, then the wonder was completed --
     * don't announce that the player has *stopped* building that wonder.
    */
    notify_player(nullptr, city_tile(pcity), E_WONDER_STOPPED, ftc_server,
                  _("The %s have stopped building The %s in %s."),
                  nation_plural_for_player(pplayer),
                  city_production_name_translation(pcity),
                  city_link(pcity));
  }
 
  /* Manage the city change-production penalty.
     (May penalize, restore or do nothing to the shield_stock.) */
  if (!is_ai(pplayer) || has_handicap(pplayer, H_PRODCHGPEN)) {
    pcity->shield_stock = city_change_production_penalty(pcity, target);
  }
 
  /* Change build target. */
  pcity->production = *target;
 
  /* What's the name of the target? */
  name = city_production_name_translation(pcity);
 
  switch (event) {
    case E_WORKLIST:
      /* TRANS: Possible 'source' of the production change
       * (in "<city> is building ..." sentence). Preserve leading space. */
      source = _(" from the worklist");
      break;
    case E_IMP_AUTO:
      /* TRANS: Possible 'source' of the production change
       * (in "<city> is building ..." sentence). Preserve leading space. */
      source = _(" as suggested by the advisor");
      break;
    default:
      source = "";
      break;
  }
 
  log_base(LOG_BUILD_TARGET, "%s started building %s%s.",
           city_name_get(pcity), name, source);
 
  /* Tell the player what's up. */
  /* FIXME: this may give bad grammar when translated if the 'source'
   * string can have multiple values. */
  notify_player(pplayer, city_tile(pcity), event, ftc_server,
                /* TRANS: "<city> is building <production><source>."
                 * 'source' might be an empty string, or a clause like
                 * " from the worklist". */
                _("%s is building %s%s."),
                city_link(pcity),
                name, source);
 
  /* If the city is building a wonder, tell the rest of the world
     about it. */
  if (VUT_IMPROVEMENT == pcity->production.kind
      && is_great_wonder(pcity->production.value.building)) {
    notify_player(nullptr, city_tile(pcity), E_WONDER_STARTED, ftc_server,
                  _("The %s have started building The %s in %s."),
                  nation_plural_for_player(pplayer),
                  name,
                  city_link(pcity));
  }
}
 
/************************************************************************/
void city_map_update_empty(struct city *pcity, struct tile *ptile)
{
  tile_set_worked(ptile, nullptr);
  send_tile_info(nullptr, ptile, FALSE);
  pcity->server.synced = FALSE;
}
 
/************************************************************************/
void city_map_update_worker(struct city *pcity, struct tile *ptile)
{
  tile_set_worked(ptile, pcity);
  send_tile_info(nullptr, ptile, FALSE);
  pcity->server.synced = FALSE;
}
 
/************************************************************************/
static bool city_map_update_tile_direct(struct tile *ptile, bool queued)
{
  struct city *pwork = tile_worked(ptile);
 
  if (pwork != nullptr
      && !is_free_worked(pwork, ptile)
      && !city_can_work_tile(pwork, ptile)) {
    tile_set_worked(ptile, nullptr);
    send_tile_info(nullptr, ptile, FALSE);
 
    pwork->specialists[DEFAULT_SPECIALIST]++; /* Keep city sanity */
    pwork->server.synced = FALSE;
 
    if (queued) {
      city_freeze_workers_queue(pwork); /* Place the displaced later */
    } else {
      city_refresh(pwork); /* Specialist added, keep citizen count sanity */
      auto_arrange_workers(pwork);
      send_city_info(nullptr, pwork);
    }
    return TRUE;
  }
 
  return FALSE;
}
 
/************************************************************************/
bool city_map_update_tile_frozen(struct tile *ptile)
{
  return city_map_update_tile_direct(ptile, TRUE);
}
 
/************************************************************************/
bool city_map_update_tile_now(struct tile *ptile)
{
  return city_map_update_tile_direct(ptile, FALSE);
}
 
/************************************************************************/
void sync_cities(void)
{
  if (send_city_suppressed) {
    return;
  }
 
  players_iterate(pplayer) {
    city_list_iterate(pplayer->cities, pcity) {
      if (!pcity->server.synced) {
        /* Sending will set to TRUE. */
        send_city_info(pplayer, pcity);
      }
    } city_list_iterate_end;
  } players_iterate_end;
}
 
/************************************************************************/
void city_map_update_all(struct city *pcity)
{
  struct tile *pcenter = city_tile(pcity);
  const struct civ_map *nmap = &(wld.map);
 
  city_tile_iterate_skip_free_worked(nmap, city_map_radius_sq_get(pcity), pcenter,
                                     ptile, _index, _x, _y) {
    /* Bypass city_map_update_tile_now() for efficiency */
    city_map_update_tile_direct(ptile, FALSE);
  } city_tile_iterate_skip_free_worked_end;
}
 
/************************************************************************/
void city_map_update_all_cities_for_player(struct player *pplayer)
{
  city_list_iterate(pplayer->cities, pcity) {
    city_freeze_workers(pcity);
    city_map_update_all(pcity);
    city_thaw_workers(pcity);
  } city_list_iterate_end;
}
 
/************************************************************************/
void city_landlocked_sell_coastal_improvements(struct tile *ptile)
{
  adjc_iterate(&(wld.map), ptile, tile1) {
    struct city *pcity = tile_city(tile1);
 
    if (pcity) {
      struct player *pplayer = city_owner(pcity);
      const struct req_context city_ctxt = {
        .player = pplayer,
        .city = pcity,
        .tile = pcity->tile,
      };
 
      /* Sell all buildings (but not Wonders) that must be next to the ocean */
      city_built_iterate(pcity, pimprove) {
        if (!can_city_sell_building(pcity, pimprove)) {
          continue;
        }
 
        requirement_vector_iterate(&pimprove->reqs, preq) {
          if ((VUT_TERRAIN == preq->source.kind
               || VUT_TERRAINCLASS == preq->source.kind
               || VUT_TERRFLAG == preq->source.kind)
              && !is_req_active(&city_ctxt, nullptr, preq, RPT_CERTAIN)) {
            int price = impr_sell_gold(pimprove);
 
            do_sell_building(pplayer, pcity, pimprove, "landlocked");
            notify_player(pplayer, tile1, E_IMP_SOLD, ftc_server,
                          PL_("You sell %s in %s (now landlocked)"
                              " for %d gold.",
                              "You sell %s in %s (now landlocked)"
                              " for %d gold.", price),
                          improvement_name_translation(pimprove),
                          city_link(pcity), price);
          }
        } requirement_vector_iterate_end;
      } city_built_iterate_end;
    }
  } adjc_iterate_end;
}
 
/************************************************************************/
void city_refresh_vision(struct city *pcity)
{
  if (pcity->server.vision != nullptr) {
    v_radius_t vision_radius_sq
      = V_RADIUS(get_city_bonus(pcity, EFT_CITY_VISION_RADIUS_SQ), 2, 2);
 
    vision_change_sight(pcity->server.vision, vision_radius_sq);
    ASSERT_VISION(pcity->server.vision);
  }
}
 
/************************************************************************/
void refresh_player_cities_vision(struct player *pplayer)
{
  city_list_iterate(pplayer->cities, pcity) {
    city_refresh_vision(pcity);
  } city_list_iterate_end;
}
 
/************************************************************************/
bool city_map_update_radius_sq(struct city *pcity)
{
  fc_assert_ret_val(pcity != nullptr, FALSE);
 
  int city_tiles_old, city_tiles_new;
  int city_radius_sq_old = city_map_radius_sq_get(pcity);
  int city_radius_sq_new = game.info.init_city_radius_sq
                           + get_city_bonus(pcity, EFT_CITY_RADIUS_SQ);
  const struct civ_map *nmap = &(wld.map);
 
  /* Check minimum / maximum allowed city radii */
  city_radius_sq_new = CLIP(CITY_MAP_MIN_RADIUS_SQ, city_radius_sq_new,
                            CITY_MAP_MAX_RADIUS_SQ);
 
  if (city_radius_sq_new == city_radius_sq_old) {
    /* No change */
    return FALSE;
  }
 
  /* Get number of city tiles for each radii */
  city_tiles_old = city_map_tiles(city_radius_sq_old);
  city_tiles_new = city_map_tiles(city_radius_sq_new);
 
  if (city_tiles_old == city_tiles_new) {
    /* A change of the squared city radius but no change of the number of
     * city tiles */
    return FALSE;
  }
 
  log_debug("[%s (%d)] city_map_radius_sq: %d => %d", city_name_get(pcity),
            pcity->id, city_radius_sq_old, city_radius_sq_new);
 
  /* Workers map before */
  log_debug("[%s (%d)] city size: %d; specialists: %d (before change)",
            city_name_get(pcity), pcity->id, city_size_get(pcity),
            city_specialists(pcity));
  citylog_map_workers(LOG_DEBUG, pcity);
 
  city_map_radius_sq_set(pcity, city_radius_sq_new);
 
  if (city_tiles_old < city_tiles_new) {
    /* Increased number of city tiles */
    city_refresh_vision(pcity);
  } else {
    /* Reduced number of city tiles */
    int workers = 0;
 
    /* Remove workers from the tiles removed rom the city map */
    city_map_iterate_radius_sq(city_radius_sq_new, city_radius_sq_old,
                               city_x, city_y) {
      struct tile *ptile = city_map_to_tile(nmap, city_tile(pcity),
                                            city_radius_sq_old, city_x,
                                            city_y);
 
      if (ptile && pcity == tile_worked(ptile)) {
        city_map_update_empty(pcity, ptile);
        workers++;
      }
    } city_map_iterate_radius_sq_end;
 
    /* Add workers to free city tiles */
    if (workers > 0) {
      int radius_sq = city_map_radius_sq_get(pcity);
 
      city_map_iterate_without_index(radius_sq, city_x, city_y) {
        struct tile *ptile = city_map_to_tile(nmap, city_tile(pcity), radius_sq,
                                              city_x, city_y);
 
        if (ptile && !is_free_worked(pcity, ptile)
            && tile_worked(ptile) != pcity
            && city_can_work_tile(pcity, ptile)) {
          city_map_update_worker(pcity, ptile);
          workers--;
        }
 
        if (workers <= 0) {
          break;
        }
      } city_map_iterate_without_index_end;
    }
 
    /* If there still are workers they will be updated to specialists */
    if (workers > 0) {
      pcity->specialists[DEFAULT_SPECIALIST] += workers;
    }
 
    city_refresh_vision(pcity);
  }
 
  /* City removal might be ongoing, and advisor data already deleted */
  if (pcity->server.adv != nullptr) {
    /* If city is under AI control, update it */
    adv_city_update(pcity);
  }
 
  notify_player(city_owner(pcity), city_tile(pcity), E_CITY_RADIUS_SQ,
                ftc_server, _("The size of the city map of %s is %s."),
                city_name_get(pcity),
                city_tiles_old < city_tiles_new ? _("increased")
                                                : _("reduced"));
 
  /* Workers map after */
  log_debug("[%s (%d)] city size: %d; specialists: %d (after change)",
            city_name_get(pcity), pcity->id, city_size_get(pcity),
            city_specialists(pcity));
  citylog_map_workers(LOG_DEBUG, pcity);
 
  return TRUE;
}
 
/************************************************************************/
void clear_worker_task(struct city *pcity, struct worker_task *ptask)
{
  struct packet_worker_task packet;
 
  if (ptask == nullptr) {
    return;
  }
 
  worker_task_list_remove(pcity->task_reqs, ptask);
 
  packet.city_id = pcity->id;
  packet.tile_id = tile_index(ptask->ptile);
  packet.activity = ACTIVITY_LAST;
  packet.tgt = 0;
  packet.want = 0;
 
  free(ptask);
 
  lsend_packet_worker_task(city_owner(pcity)->connections, &packet);
  lsend_packet_worker_task(game.glob_observers, &packet);
}
 
/************************************************************************/
void clear_worker_tasks(struct city *pcity)
{
  while (worker_task_list_size(pcity->task_reqs) > 0) {
    clear_worker_task(pcity, worker_task_list_get(pcity->task_reqs, 0));
  }
}
 
/************************************************************************/
void package_and_send_worker_tasks(struct city *pcity)
{
  struct packet_worker_task packet;
 
  packet.city_id = pcity->id;
 
  worker_task_list_iterate(pcity->task_reqs, ptask) {
    packet.tile_id = tile_index(ptask->ptile);
    packet.activity = ptask->act;
    if (ptask->tgt == nullptr) {
      packet.tgt = -1;
    } else {
      packet.tgt = extra_number(ptask->tgt);
    }
    packet.want = ptask->want;
 
    lsend_packet_worker_task(city_owner(pcity)->connections, &packet);
    lsend_packet_worker_task(game.glob_observers, &packet);
  } worker_task_list_iterate_end;
}
 
/************************************************************************/
int city_production_buy_gold_cost(const struct city *pcity)
{
  int build = pcity->shield_stock;
 
  switch (pcity->production.kind) {
  case VUT_IMPROVEMENT:
    return impr_buy_gold_cost(pcity, pcity->production.value.building,
                              build);
  case VUT_UTYPE:
    return utype_buy_gold_cost(pcity, pcity->production.value.utype,
                               build);
  default:
    break;
  };
 
  return FC_INFINITY;
}
 
/************************************************************************/
void city_add_improvement_with_gov_notice(struct city *pcity,
                                          const struct impr_type *pimprove,
                                          const char *format)
{
  if (is_wonder(pimprove)) {
    /* Only wonders may grant governments */
    struct cur_govs_data *govs_data;
    char buf[250];
 
    govs_data = create_current_governments_data_all();
    city_add_improvement(pcity, pimprove);
 
    fc_snprintf(buf, sizeof(buf), format,
                improvement_name_translation(pimprove));
 
    players_iterate_alive(pplayer) {
      notify_new_government_options(pplayer, govs_data, buf);
    } players_iterate_alive_end;
 
    free_current_governments_data(govs_data);
  } else {
    city_add_improvement(pcity, pimprove);
  }
}
 
/************************************************************************/
int city_original_owner(const struct city *pcity,
                        const struct player *known_for)
{
  if (pcity->original == nullptr) {
    /* Nobody knows */
    return MAX_NUM_PLAYER_SLOTS;
  }
 
  if (pcity->original != known_for
      || known_for == nullptr) {
    /* Players know what they have built themselves,
     * global observer knows everything. */
    return player_number(pcity->original);
  }
 
  return MAX_NUM_PLAYER_SLOTS;
}