diff -ruN -Xdiff_ignore freeciv_cvs/server/cityturn.c freeciv/server/cityturn.c
--- freeciv_cvs/server/cityturn.c	Wed Jan 24 16:39:15 2001
+++ freeciv/server/cityturn.c	Wed Jan 24 17:27:26 2001
@@ -1276,7 +1276,8 @@
   struct government *g = get_gov_pplayer(pplayer);
   int space_part;
   int city_built_city_builder;
-
+  int production_overflow;
+  
   while (pcity->shield_surplus<0) {
     unit_list_iterate(pcity->units_supported, punit) {
       if (utype_shield_cost(get_unit_type(punit->type), g)) {
@@ -1290,7 +1291,18 @@
     unit_list_iterate_end;
   }
 
-  pcity->shield_stock+=pcity->shield_surplus;
+  if (!pcity->is_building_unit &&
+      pcity->shield_stock > improvement_value (pcity->currently_building))
+    production_overflow = pcity->shield_stock -
+      improvement_value (pcity->currently_building);
+  else if (pcity->is_building_unit &&
+  	 pcity->shield_stock > unit_value (pcity->currently_building))
+    production_overflow = pcity->shield_stock -
+      unit_value (pcity->currently_building);
+  else
+    production_overflow = 0;
+	
+  pcity->shield_stock+=pcity->shield_surplus;
   if (!pcity->is_building_unit) {
     if (pcity->currently_building==B_CAPITAL) {
       pplayer->economic.gold+=pcity->shield_surplus;
@@ -1441,7 +1453,11 @@
 
     }
   }
-return 1;
+
+  if (pcity->turn_last_built == game.year && production_overflow)
+    pcity->shield_stock -= (production_overflow + 1) / 2;
+
+  return 1;
 }
 
 /**************************************************************************