Index: client/citydlg_common.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/citydlg_common.c,v
retrieving revision 1.6
diff -u -r1.6 citydlg_common.c
--- client/citydlg_common.c	2002/03/14 20:41:10	1.6
+++ client/citydlg_common.c	2002/06/30 16:04:33
@@ -121,7 +121,7 @@
 
   if (!pcity->is_building_unit && pcity->currently_building == B_CAPITAL) {
     my_snprintf(buffer, buffer_len, _("%3d gold per turn"),
-		pcity->shield_surplus);
+		MAX(0, pcity->shield_surplus));
   } else {
     char time[50];
 
@@ -161,9 +161,8 @@
 				     struct city *pcity)
 {
   if (!is_unit && id == B_CAPITAL) {
-    my_snprintf(buffer, buffer_len,
-		"%s (XX) %d/turn",
-		get_impr_name_ex(pcity, id), pcity->shield_surplus);
+    my_snprintf(buffer, buffer_len, "%s (XX) %d/turn",
+		get_impr_name_ex(pcity, id), MAX(0, pcity->shield_surplus));
   } else {
     int turns = city_turns_to_build(pcity, id, is_unit, TRUE);
     char *name;
@@ -246,7 +245,8 @@
   /* Add the turns-to-build entry in the 4th position */
   if (pcity) {
     if (!is_unit && id == B_CAPITAL) {
-      my_snprintf(buf[3], column_size, "%d/turn", pcity->shield_surplus);
+      my_snprintf(buf[3], column_size, "%d/turn",
+		  MAX(0, pcity->shield_surplus));
     } else {
       int turns = city_turns_to_build(pcity, id, is_unit, FALSE);
       if (turns < 999) {
Index: client/cityrepdata.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/cityrepdata.c,v
retrieving revision 1.18
diff -u -r1.18 cityrepdata.c
--- client/cityrepdata.c	2002/03/17 10:48:49	1.18
+++ client/cityrepdata.c	2002/06/30 16:04:33
@@ -148,7 +148,7 @@
   if (!pcity->is_building_unit && pcity->currently_building == B_CAPITAL) {
     my_snprintf(buf, sizeof(buf), "%s (%d/X/X/X)%s",
 		get_impr_name_ex(pcity, pcity->currently_building),
-		pcity->shield_stock, from_worklist);
+		MAX(0, pcity->shield_surplus), from_worklist);
   } else {
     int turns = city_turns_to_build(pcity, pcity->currently_building,
 				    pcity->is_building_unit, TRUE);
Index: client/repodlgs_common.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/repodlgs_common.c,v
retrieving revision 1.2
diff -u -r1.2 repodlgs_common.c
--- client/repodlgs_common.c	2002/06/27 00:59:12	1.2
+++ client/repodlgs_common.c	2002/06/30 16:04:33
@@ -59,7 +59,7 @@
   city_list_iterate(game.player_ptr->cities, pcity) {
     *total_income += pcity->tax_total;
     if (!pcity->is_building_unit && pcity->currently_building == B_CAPITAL) {
-      *total_income += pcity->shield_surplus;
+      *total_income += MAX(0, pcity->shield_surplus);
     }
   } city_list_iterate_end;
 }
Index: server/cityturn.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/cityturn.c,v
retrieving revision 1.191
diff -u -r1.191 cityturn.c
--- server/cityturn.c	2002/06/09 15:10:13	1.191
+++ server/cityturn.c	2002/06/30 16:04:35
@@ -905,6 +905,7 @@
   bool space_part;
 
   if (pcity->currently_building == B_CAPITAL) {
+    assert(pcity->shield_surplus >= 0);
     pplayer->economic.gold += pcity->shield_surplus;
     pcity->before_change_shields = 0;
     pcity->shield_stock = 0;