From 8e9f39887f8db1e005897af0f5119b2c5ae51a20 Mon Sep 17 00:00:00 2001
From: Marko Lindqvist <cazfi74@gmail.com>
Date: Sat, 30 Sep 2023 22:29:34 +0300
Subject: [PATCH 31/31] Check "Tile_Workable" effect value at turn change

Make cities to stop working tiles they no longer can.

Reported by ihnatus

See osdn #46423

Signed-off-by: Marko Lindqvist <cazfi74@gmail.com>
---
 server/cityturn.c | 24 ++++++++++++++++++++++++
 server/cityturn.h |  2 ++
 server/srv_main.c |  1 +
 3 files changed, 27 insertions(+)

diff --git a/server/cityturn.c b/server/cityturn.c
index 68fac21309..313f64d062 100644
--- a/server/cityturn.c
+++ b/server/cityturn.c
@@ -4368,3 +4368,27 @@ void city_style_refresh(struct city *pcity)
 {
   pcity->style = city_style(pcity);
 }
+
+/**********************************************************************//**
+  Recalculate some city related effects on turn change
+**************************************************************************/
+void city_tc_effect_refresh(struct player *pplayer)
+{
+  city_list_iterate(pplayer->cities, pcity) {
+    bool changed = FALSE;
+
+    city_tile_iterate_skip_free_worked(city_map_radius_sq_get(pcity),
+                                       city_tile(pcity), ptile, idx, x, y) {
+      if (get_city_tile_output_bonus(pcity, ptile, NULL, EFT_TILE_WORKABLE) <= 0) {
+        city_map_update_empty(pcity, ptile);
+        pcity->specialists[DEFAULT_SPECIALIST]++;
+        changed = TRUE;
+      }
+    } city_tile_iterate_skip_free_worked_end;
+
+    if (changed) {
+      auto_arrange_workers(pcity);
+      send_city_info(NULL, pcity);
+    }
+  } city_list_iterate_end;
+}
diff --git a/server/cityturn.h b/server/cityturn.h
index 9b833c9d19..e4cc0d7a9d 100644
--- a/server/cityturn.h
+++ b/server/cityturn.h
@@ -53,6 +53,8 @@ bool check_city_migrations(void);
 
 void check_disasters(void);
 
+void city_tc_effect_refresh(struct player *pplayer);
+
 void city_style_refresh(struct city *pcity);
 
 #endif  /* FC__CITYTURN_H */
diff --git a/server/srv_main.c b/server/srv_main.c
index 08bc89456d..c341c8a7b0 100644
--- a/server/srv_main.c
+++ b/server/srv_main.c
@@ -1282,6 +1282,7 @@ static void begin_phase(bool is_new_phase)
     } phase_players_iterate_end;
 
     phase_players_iterate(pplayer) {
+      city_tc_effect_refresh(pplayer);
       unit_tc_effect_refresh(pplayer);
     } phase_players_iterate_end;
 
-- 
2.40.1