From 991f5bbd036b39aef6b45ef938c4923aea1bbf56 Mon Sep 17 00:00:00 2001
From: Marko Lindqvist <cazfi74@gmail.com>
Date: Thu, 12 Oct 2023 22:12:10 +0300
Subject: [PATCH 8/8] Player removal: Clear city border claims

See osdn #48837

Signed-off-by: Marko Lindqvist <cazfi74@gmail.com>
---
 client/client_main.c              | 1 +
 common/fc_interface.h             | 1 +
 common/player.c                   | 6 +++++-
 server/citytools.c                | 9 ++++++---
 server/srv_main.c                 | 1 +
 server/unittools.c                | 8 +++++---
 tools/shared/tools_fc_interface.c | 2 ++
 7 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/client/client_main.c b/client/client_main.c
index a6e49549db..db6d6fd389 100644
--- a/client/client_main.c
+++ b/client/client_main.c
@@ -1526,6 +1526,7 @@ static void fc_interface_init_client(void)
   funcs->server_setting_val_bitwise_get = client_ss_val_bitwise_get;
   funcs->create_extra = NULL;
   funcs->destroy_extra = NULL;
+  funcs->destroy_city = NULL;
   funcs->player_tile_vision_get = client_map_is_known_and_seen;
   funcs->player_tile_city_id_get = client_plr_tile_city_id_get;
   funcs->gui_color_free = color_free;
diff --git a/common/fc_interface.h b/common/fc_interface.h
index bf13601545..be510c9fac 100644
--- a/common/fc_interface.h
+++ b/common/fc_interface.h
@@ -40,6 +40,7 @@ struct functions {
   void (*create_extra)(struct tile *ptile, struct extra_type *pextra,
                        struct player *pplayer);
   void (*destroy_extra)(struct tile *ptile, struct extra_type *pextra);
+  void (*destroy_city)(struct city *pcity);
   /* Returns iff the player 'pplayer' has the vision in the layer
      'vision' at tile given by 'ptile'. */
   bool (*player_tile_vision_get)(const struct tile *ptile,
diff --git a/common/player.c b/common/player.c
index 1e05c2f3d3..87f3b3e972 100644
--- a/common/player.c
+++ b/common/player.c
@@ -698,7 +698,11 @@ void player_clear(struct player *pplayer, bool full)
   } unit_list_iterate_end;
 
   city_list_iterate(pplayer->cities, pcity) {
-    game_remove_city(pcity);
+    if (fc_funcs->destroy_city != NULL) {
+      fc_funcs->destroy_city(pcity);
+    } else {
+      game_remove_city(pcity);
+    }
   } city_list_iterate_end;
 
   if (full) {
diff --git a/server/citytools.c b/server/citytools.c
index c01356f8f2..9676140528 100644
--- a/server/citytools.c
+++ b/server/citytools.c
@@ -1689,7 +1689,7 @@ void remove_city(struct city *pcity)
     }
   } unit_list_iterate_safe_end;
 
-  /* make sure ships are not left on land when city is removed. */
+  /* Make sure ships are not left on land when city is removed. */
   unit_list_iterate_safe(pcenter->units, punit) {
     bool moved;
     struct unit_type *punittype = unit_type_get(punit);
@@ -1732,6 +1732,7 @@ void remove_city(struct city *pcity)
   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(ptile, piter) {
@@ -1855,8 +1856,10 @@ void remove_city(struct city *pcity)
     }
   } conn_list_iterate_end;
 
-  vision_clear_sight(old_vision);
-  vision_free(old_vision);
+  if (old_vision != NULL) {
+    vision_clear_sight(old_vision);
+    vision_free(old_vision);
+  }
 
   /* Infrastructures may have changed. */
   send_tile_info(NULL, pcenter, FALSE);
diff --git a/server/srv_main.c b/server/srv_main.c
index 474b00febf..d4f203cdf6 100644
--- a/server/srv_main.c
+++ b/server/srv_main.c
@@ -3554,6 +3554,7 @@ static void fc_interface_init_server(void)
   funcs->server_setting_val_bitwise_get = server_ss_val_bitwise_get;
   funcs->create_extra = create_extra;
   funcs->destroy_extra = destroy_extra;
+  funcs->destroy_city = remove_city;
   funcs->player_tile_vision_get = map_is_known_and_seen;
   funcs->player_tile_city_id_get = server_plr_tile_city_id_get;
   funcs->gui_color_free = server_gui_color_free;
diff --git a/server/unittools.c b/server/unittools.c
index e1fd63fb9f..2c2f79b7e1 100644
--- a/server/unittools.c
+++ b/server/unittools.c
@@ -3895,9 +3895,11 @@ bool unit_move(struct unit *punit, struct tile *pdesttile, int move_cost,
 
   /* Clear old vision. */
   unit_move_data_list_iterate(plist, pmove_data) {
-    vision_clear_sight(pmove_data->old_vision);
-    vision_free(pmove_data->old_vision);
-    pmove_data->old_vision = NULL;
+    if (pmove_data->old_vision != NULL) {
+      vision_clear_sight(pmove_data->old_vision);
+      vision_free(pmove_data->old_vision);
+      pmove_data->old_vision = NULL;
+    }
   } unit_move_data_list_iterate_end;
 
   /* Move consequences. */
diff --git a/tools/shared/tools_fc_interface.c b/tools/shared/tools_fc_interface.c
index f99acbc038..d0f73ec878 100644
--- a/tools/shared/tools_fc_interface.c
+++ b/tools/shared/tools_fc_interface.c
@@ -61,6 +61,8 @@ void fc_interface_init_tool(void)
 {
   struct functions *funcs = fc_interface_funcs();
 
+  memset(funcs, 0, sizeof(*funcs));
+
   /* May be used when generating help texts */
   funcs->server_setting_by_name = server_ss_by_name;
   funcs->server_setting_name_get = server_ss_name_get;
-- 
2.42.0