[Freeciv-Dev] (PR#9800) unit_type_exists should be removed

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=9800 >

This patch removes unit_type_exists.

In most places where this function used to be called we can simply
ignore it.  In a few places we need to check the type against -1
(U_NONE) instead.  I added a new macro CHECK_UNIT_TYPE which verifies
the unit type is valid.

IMO this makes things a fair bit simpler.  Only 40 lines of code are
removed but the logic is a lot cleaner.

Also I removed all the nonexistent units (necessary for the code patch,
but it can be applied separately).  They were previously needed for
backwards-compatibility with savegames, but aren't any more.  This
removes 800 lines of ruleset data...

jason

Index: ai/aiunit.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.c,v
retrieving revision 1.334
diff -u -r1.334 aiunit.c
--- ai/aiunit.c 1 Sep 2004 11:47:25 -0000       1.334
+++ ai/aiunit.c 3 Sep 2004 04:28:37 -0000
@@ -2412,7 +2412,7 @@
   int i = 0;
 
   unit_type_iterate(id) {
-    if (unit_type_exists(id) && !unit_type_flag(id, F_NONMIL)
+    if (!unit_type_flag(id, F_NONMIL)
        && !unit_type_flag(id, F_MISSILE)
        && !unit_type_flag(id, F_NO_LAND_ATTACK)
         && get_unit_type(id)->move_type != AIR_MOVING
Index: client/helpdata.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/helpdata.c,v
retrieving revision 1.73
diff -u -r1.73 helpdata.c
--- client/helpdata.c   31 Aug 2004 04:40:48 -0000      1.73
+++ client/helpdata.c   3 Sep 2004 04:28:37 -0000
@@ -241,13 +241,11 @@
        help_list_init(&category_nodes);
        if (current_type == HELP_UNIT) {
          unit_type_iterate(i) {
-           if (unit_type_exists(i)) {
-             pitem = new_help_item(current_type);
-             my_snprintf(name, sizeof(name), " %s", unit_name(i));
-             pitem->topic = mystrdup(name);
-             pitem->text = mystrdup("");
-             help_list_insert_back(&category_nodes, pitem);
-           }
+           pitem = new_help_item(current_type);
+           my_snprintf(name, sizeof(name), " %s", unit_name(i));
+           pitem->topic = mystrdup(name);
+           pitem->text = mystrdup("");
+           help_list_insert_back(&category_nodes, pitem);
          } unit_type_iterate_end;
        } else if (current_type == HELP_TECH) {
          tech_type_iterate(i) {
@@ -561,10 +559,6 @@
   struct unit_type *utype;
 
   assert(buf&&user_text);
-  if (!unit_type_exists(i)) {
-    strcpy(buf, user_text);
-    return;
-  }
   utype = get_unit_type(i);
   
   buf[0] = '\0';
Index: client/options.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/options.c,v
retrieving revision 1.103
diff -u -r1.103 options.c
--- client/options.c    26 Aug 2004 07:59:01 -0000      1.103
+++ client/options.c    3 Sep 2004 04:28:38 -0000
@@ -721,8 +721,10 @@
         secfile_lookup_int_default(file, 0, idpath,wlinx, i);
 
       if ((pwl->wlefs[i] <= WEF_END) || (pwl->wlefs[i] >= WEF_LAST) ||
-          ((pwl->wlefs[i] == WEF_UNIT) && !unit_type_exists(pwl->wlids[i])) ||
-          ((pwl->wlefs[i] == WEF_IMPR) && !improvement_exists(pwl->wlids[i]))) 
{
+          (pwl->wlefs[i] == WEF_UNIT
+          && (pwl->wlids[i] < 0 || pwl->wlids[i] >= game.num_unit_types))
+          || ((pwl->wlefs[i] == WEF_IMPR)
+              && !improvement_exists(pwl->wlids[i]))) {
         pwl->wlefs[i] = WEF_END;
         pwl->wlids[i] = 0;
         end = TRUE;
Index: client/tilespec.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/tilespec.c,v
retrieving revision 1.196
diff -u -r1.196 tilespec.c
--- client/tilespec.c   25 Aug 2004 18:24:18 -0000      1.196
+++ client/tilespec.c   3 Sep 2004 04:28:38 -0000
@@ -1547,8 +1547,7 @@
   struct unit_type *ut = get_unit_type(id);
   
   ut->sprite = lookup_sprite_tag_alt(ut->graphic_str, ut->graphic_alt,
-                                    unit_type_exists(id), "unit_type",
-                                    ut->name);
+                                    TRUE, "unit_type", ut->name);
 
   /* should maybe do something if NULL, eg generic default? */
 }
Index: client/gui-gtk/repodlgs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk/repodlgs.c,v
retrieving revision 1.83
diff -u -r1.83 repodlgs.c
--- client/gui-gtk/repodlgs.c   2 Aug 2004 23:44:57 -0000       1.83
+++ client/gui-gtk/repodlgs.c   3 Sep 2004 04:28:38 -0000
@@ -913,9 +913,10 @@
 *****************************************************************/
 void activeunits_list_callback(GtkWidget *w, gint row, gint column)
 {
-  if ((unit_type_exists(activeunits_type[row])) &&
-      (can_upgrade_unittype(game.player_ptr, activeunits_type[row]) != -1))
+  CHECK_UNIT_TYPE(activeunits_type[row]);
+  if (can_upgrade_unittype(game.player_ptr, activeunits_type[row]) != -1) {
     gtk_widget_set_sensitive(upgrade_command, can_client_issue_orders());
+  }
 }
 
 /****************************************************************
@@ -950,8 +951,7 @@
   row = GPOINTER_TO_INT(selection->data);
 
   ut1 = activeunits_type[row];
-  if (!(unit_type_exists (ut1)))
-    return;
+  CHECCK_UNIT_TYPE(ut1);
   /* puts(unit_types[ut1].name); */
 
   ut2 = can_upgrade_unittype(game.player_ptr, activeunits_type[row]);
@@ -1027,9 +1027,9 @@
     }
     unit_list_iterate_end;
     city_list_iterate(game.player_ptr->cities,pcity) {
-      if (pcity->is_building_unit &&
-         (unit_type_exists (pcity->currently_building)))
+      if (pcity->is_building_unit) {
        (unitarray[pcity->currently_building].building_count)++;
+      }
     }
     city_list_iterate_end;
 
Index: client/gui-gtk-2.0/repodlgs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk-2.0/repodlgs.c,v
retrieving revision 1.55
diff -u -r1.55 repodlgs.c
--- client/gui-gtk-2.0/repodlgs.c       28 Aug 2004 07:21:02 -0000      1.55
+++ client/gui-gtk-2.0/repodlgs.c       3 Sep 2004 04:28:39 -0000
@@ -1039,11 +1039,7 @@
     
     n = gtk_tree_model_iter_n_children(GTK_TREE_MODEL(activeunits_store), 
NULL);
 
-    if (row < n - 1 && unit_type_exists(activeunits_type[row])) {
-      is_unit_type = TRUE;
-    } else {
-      is_unit_type = FALSE;
-    }
+    is_unit_type = (row < n - 1);
   }
 
   if (!is_unit_type) {
@@ -1119,10 +1115,7 @@
   /* nearest & upgrade commands. */
   row = gtk_tree_selection_get_row(activeunits_selection);
   ut1 = activeunits_type[row];
-
-  if (!unit_type_exists(ut1)) {
-    return;
-  }
+  CHECK_UNIT_TYPE(ut1);
 
   if (response_id == ACTIVEUNITS_NEAREST) {
     int cx, cy;
@@ -1192,9 +1185,9 @@
     }
     unit_list_iterate_end;
     city_list_iterate(game.player_ptr->cities,pcity) {
-      if (pcity->is_building_unit &&
-         (unit_type_exists (pcity->currently_building)))
+      if (pcity->is_building_unit) {
        (unitarray[pcity->currently_building].building_count)++;
+      }
     }
     city_list_iterate_end;
 
Index: client/gui-mui/repodlgs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-mui/repodlgs.c,v
retrieving revision 1.36
diff -u -r1.36 repodlgs.c
--- client/gui-mui/repodlgs.c   19 Jul 2004 20:29:12 -0000      1.36
+++ client/gui-mui/repodlgs.c   3 Sep 2004 04:28:39 -0000
@@ -820,9 +820,9 @@
 
   city_list_iterate(game.player_ptr->cities, pcity)
   {
-    if (pcity->is_building_unit &&
-       (unit_type_exists(pcity->currently_building)))
+    if (pcity->is_building_unit) {
       (unitarray[pcity->currently_building].building_count)++;
+    }
   }
   city_list_iterate_end;
 
Index: client/gui-sdl/dialogs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-sdl/dialogs.c,v
retrieving revision 1.47
diff -u -r1.47 dialogs.c
--- client/gui-sdl/dialogs.c    13 Jul 2004 22:52:16 -0000      1.47
+++ client/gui-sdl/dialogs.c    3 Sep 2004 04:28:39 -0000
@@ -406,11 +406,12 @@
   
   ut1 = pUnit->type;
   
-  if (pUnit_Upgrade_Dlg || !unit_type_exists(ut1)) {
+  if (pUnit_Upgrade_Dlg) {
     /* just in case */
     flush_dirty();
     return;
   }
+  CHECK_UNIT_TYPE(ut1);
     
   pUnit_Upgrade_Dlg = MALLOC(sizeof(struct SMALL_DLG));
 
Index: client/gui-sdl/repodlgs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-sdl/repodlgs.c,v
retrieving revision 1.37
diff -u -r1.37 repodlgs.c
--- client/gui-sdl/repodlgs.c   23 Apr 2004 22:58:05 -0000      1.37
+++ client/gui-sdl/repodlgs.c   3 Sep 2004 04:28:40 -0000
@@ -104,13 +104,12 @@
   } unit_list_iterate_end;
     
   city_list_iterate(game.player_ptr->cities, pCity) {
-    if (pCity->is_building_unit &&
-      (unit_type_exists(pCity->currently_building))) {
-        (entries[pCity->currently_building].building_count)++;
-       (total->building_count)++;
-        entries[pCity->currently_building].soonest_completions =
-               MIN(entries[pCity->currently_building].soonest_completions,
-                       city_turns_to_build(pCity,
+    if (pCity->is_building_unit) {
+      (entries[pCity->currently_building].building_count)++;
+      (total->building_count)++;
+      entries[pCity->currently_building].soonest_completions =
+       MIN(entries[pCity->currently_building].soonest_completions,
+           city_turns_to_build(pCity,
                                pCity->currently_building, TRUE, TRUE));
     }
   } city_list_iterate_end;
@@ -173,9 +172,10 @@
   
   ut1 = MAX_ID - pWidget->ID;
   
-  if (pUnits_Upg_Dlg || !unit_type_exists(ut1)) {
+  if (pUnits_Upg_Dlg) {
     return 1;
   }
+  CHECK_UNIT_TYPE(ut1);
   
   set_wstate(pWidget, FC_WS_NORMAL);
   pSellected_Widget = NULL;
Index: client/gui-win32/repodlgs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-win32/repodlgs.c,v
retrieving revision 1.39
diff -u -r1.39 repodlgs.c
--- client/gui-win32/repodlgs.c 28 Aug 2004 00:54:05 -0000      1.39
+++ client/gui-win32/repodlgs.c 3 Sep 2004 04:28:40 -0000
@@ -486,14 +486,15 @@
       
     case WM_NOTIFY:
       if (sel>=0) {
-       if ((unit_type_exists(activeunits_type[sel])) &&
-           (can_upgrade_unittype(game.player_ptr,
-                                 activeunits_type[sel]) != -1))    
+       CHECK_UNIT_TYPE(activeunits_type[sel]);
+       if (can_upgrade_unittype(game.player_ptr,
+                                activeunits_type[sel]) != -1) {
          EnableWindow(GetDlgItem(activeunits_dlg,ID_MILITARY_UPGRADE),
                       TRUE);
-       else
+       } else {
          EnableWindow(GetDlgItem(activeunits_dlg,ID_MILITARY_UPGRADE),
                       FALSE);
+       }
       }
       break;
     case WM_COMMAND:    
@@ -511,9 +512,9 @@
            {
              char buf[512];
              int ut1,ut2;     
+
              ut1 = activeunits_type[sel];
-             if (!(unit_type_exists (ut1)))
-               break;
+             CHECK_UNIT_TYPE(ut1);
              ut2=can_upgrade_unittype(game.player_ptr,activeunits_type[sel]);
              my_snprintf(buf, sizeof(buf),
                          _("Upgrade as many %s to %s as possible for %d gold 
each?\n"
@@ -581,9 +582,9 @@
 
     unit_list_iterate_end;
     city_list_iterate(game.player_ptr->cities,pcity) {
-      if (pcity->is_building_unit &&
-          (unit_type_exists (pcity->currently_building)))
+      if (pcity->is_building_unit) {
         (unitarray[pcity->currently_building].building_count)++;
+      }
     }
     city_list_iterate_end;
 
Index: client/gui-xaw/repodlgs.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-xaw/repodlgs.c,v
retrieving revision 1.61
diff -u -r1.61 repodlgs.c
--- client/gui-xaw/repodlgs.c   19 Jul 2004 20:29:12 -0000      1.61
+++ client/gui-xaw/repodlgs.c   3 Sep 2004 04:28:40 -0000
@@ -917,7 +917,6 @@
 
   may_upgrade =
     ((inx != XAW_LIST_NONE) &&
-     (unit_type_exists (activeunits_type[inx])) &&
      (can_upgrade_unittype (game.player_ptr, activeunits_type[inx]) != -1));
 
   XtSetSensitive (upgrade_command, may_upgrade);
@@ -956,9 +955,8 @@
 
   if(ret->list_index!=XAW_LIST_NONE) {
     ut1 = activeunits_type[ret->list_index];
-    if (!(unit_type_exists (ut1))) {
-      return;
-    }
+    CHECK_UNIT_TYPE(ut1);
+
     /* puts(unit_types[ut1].name); */
 
     ut2 = can_upgrade_unittype(game.player_ptr,
@@ -1041,9 +1039,9 @@
     }
     unit_list_iterate_end;
     city_list_iterate(game.player_ptr->cities,pcity) {
-      if (pcity->is_building_unit &&
-         (unit_type_exists (pcity->currently_building)))
+      if (pcity->is_building_unit) {
        (unitarray[pcity->currently_building].building_count)++;
+      }
     }
     city_list_iterate_end;
 
Index: common/city.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/city.c,v
retrieving revision 1.240
diff -u -r1.240 city.c
--- common/city.c       1 Sep 2004 19:45:19 -0000       1.240
+++ common/city.c       3 Sep 2004 04:28:41 -0000
@@ -484,7 +484,7 @@
   if (!can_build_unit_direct(pcity, id)) {
     return FALSE;
   }
-  while (unit_type_exists((id = unit_types[id].obsoleted_by))) {
+  while ((id = unit_types[id].obsoleted_by) != -1) {
     if (can_player_build_unit_direct(city_owner(pcity), id)) {
        return FALSE;
     }
Index: common/combat.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/combat.c,v
retrieving revision 1.45
diff -u -r1.45 combat.c
--- common/combat.c     25 Aug 2004 18:24:19 -0000      1.45
+++ common/combat.c     3 Sep 2004 04:28:41 -0000
@@ -407,7 +407,11 @@
 {
   struct city *pcity = map_get_city(x, y);
 
-  if (unit_type_exists(att_type)) {
+  CHECK_UNIT_TYPE(def_type);
+
+  if (att_type != U_LAST) {
+    CHECK_UNIT_TYPE(att_type);
+
     if (unit_type_flag(def_type, F_PIKEMEN)
        && unit_type_flag(att_type, F_HORSE)) {
       defensepower *= 2;
Index: common/unittype.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/unittype.c,v
retrieving revision 1.39
diff -u -r1.39 unittype.c
--- common/unittype.c   26 Aug 2004 06:26:09 -0000      1.39
+++ common/unittype.c   3 Sep 2004 04:28:41 -0000
@@ -67,21 +67,6 @@
 };
 
 /**************************************************************************
-Returns 1 if the unit_type "exists" in this game, 0 otherwise.
-A unit_type doesn't exist if one of:
-- id is out of range
-- the unit_type has been flagged as removed by setting its
-  tech_requirement to A_LAST.
-**************************************************************************/
-bool unit_type_exists(Unit_Type_id id)
-{
-  if (id<0 || id>=U_LAST || id>=game.num_unit_types)
-    return FALSE;
-  else 
-    return unit_types[id].tech_requirement!=A_LAST;
-}
-
-/**************************************************************************
 ...
 **************************************************************************/
 struct unit_type *get_unit_type(Unit_Type_id id)
@@ -340,9 +325,11 @@
 
   if (!can_player_build_unit_direct(pplayer, id))
     return -1;
-  while (unit_type_exists(id = unit_types[id].obsoleted_by))
-    if (can_player_build_unit_direct(pplayer, id))
+  while ((id = unit_types[id].obsoleted_by) != -1) {
+    if (can_player_build_unit_direct(pplayer, id)) {
       best_upgrade = id;
+    }
+  }
 
   return best_upgrade;
 }
@@ -474,8 +461,7 @@
   Impr_Type_id impr_req;
   Tech_Type_id tech_req;
 
-  if (!unit_type_exists(id))
-    return FALSE;
+  CHECK_UNIT_TYPE(id);
   if (unit_type_flag(id, F_NUCLEAR) && game.global_wonders[B_MANHATTEN] == 0)
     return FALSE;
   if (unit_type_flag(id, F_NOBUILD)) {
@@ -517,9 +503,11 @@
 {  
   if (!can_player_build_unit_direct(p, id))
     return FALSE;
-  while(unit_type_exists((id = unit_types[id].obsoleted_by)))
-    if (can_player_build_unit_direct(p, id))
+  while ((id = unit_types[id].obsoleted_by) != -1) {
+    if (can_player_build_unit_direct(p, id)) {
        return FALSE;
+    }
+  }
   return TRUE;
 }
 
@@ -530,13 +518,11 @@
 **************************************************************************/
 bool can_player_eventually_build_unit(struct player *p, Unit_Type_id id)
 {
-  if (!unit_type_exists(id)) {
-    return FALSE;
-  }
+  CHECK_UNIT_TYPE(id);
   if (unit_type_flag(id, F_NOBUILD)) {
     return FALSE;
   }
-  while (unit_type_exists((id = unit_types[id].obsoleted_by))) {
+  while ((id = unit_types[id].obsoleted_by) != -1) {
     if (can_player_build_unit_direct(p, id)) {
        return FALSE;
     }
@@ -549,7 +535,6 @@
 which unit types have given flag or role.
 For these functions flags and roles are considered to be in the same "space",
 and any "role" argument can also be a "flag".
-Only units which pass unit_type_exists are counted.
 Unit order is in terms of the order in the units ruleset.
 **************************************************************************/
 static bool first_init = TRUE;
@@ -565,7 +550,7 @@
 
   /* Count: */
   unit_type_iterate(u) {
-    if(unit_type_exists(u) && func_has(u, i)) {
+    if (func_has(u, i)) {
       n_with_role[i]++;
     }
   } unit_type_iterate_end;
@@ -574,7 +559,7 @@
     with_role[i] = fc_malloc(n_with_role[i]*sizeof(Unit_Type_id));
     j = 0;
     unit_type_iterate(u) {
-      if(unit_type_exists(u) && func_has(u, i)) {
+      if (func_has(u, i)) {
        with_role[i][j++] = u;
       }
     } unit_type_iterate_end;
Index: common/unittype.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/unittype.h,v
retrieving revision 1.30
diff -u -r1.30 unittype.h
--- common/unittype.h   20 Jul 2004 10:54:30 -0000      1.30
+++ common/unittype.h   3 Sep 2004 04:28:41 -0000
@@ -223,8 +223,8 @@
 
 
 extern struct unit_type unit_types[U_LAST];
+#define CHECK_UNIT_TYPE(ut) (assert((ut) >= 0 && (ut) < game.num_unit_types))
 
-bool unit_type_exists(Unit_Type_id id);
 struct unit_type *get_unit_type(Unit_Type_id id);
 struct unit_type *unit_type(struct unit *punit);
 
Index: server/cityturn.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/cityturn.c,v
retrieving revision 1.258
diff -u -r1.258 cityturn.c
--- server/cityturn.c   28 Aug 2004 19:15:39 -0000      1.258
+++ server/cityturn.c   3 Sep 2004 04:28:43 -0000
@@ -804,6 +804,8 @@
   we can build.  Return id if we can't upgrade at all.  NB:  returning
   id doesn't guarantee that pcity really _can_ build id; just that
   pcity can't build whatever _obsoletes_ id.
+
+  FIXME: this function is a duplicate of can_upgrade_unittype.
 **************************************************************************/
 static Unit_Type_id unit_upgrades_to(struct city *pcity, Unit_Type_id id)
 {
@@ -812,7 +814,7 @@
   if (!can_build_unit_direct(pcity, check)) {
     return -1;
   }
-  while(unit_type_exists(check = unit_types[check].obsoleted_by)) {
+  while ((check = unit_types[check].obsoleted_by) != -1) {
     if (can_build_unit_direct(pcity, check)) {
       latest_ok = check;
     }
@@ -833,7 +835,7 @@
   int id = pcity->currently_building;
   int id2 = unit_upgrades_to(pcity, pcity->currently_building);
 
-  if (can_build_unit_direct(pcity, id2)) {
+  if (id2 != -1 && can_build_unit_direct(pcity, id2)) {
     pcity->currently_building = id2;
     notify_player_ex(pplayer, pcity->x, pcity->y, E_UNIT_UPGRADED, 
                  _("Game: Production of %s is upgraded to %s in %s."),
Index: server/ruleset.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/ruleset.c,v
retrieving revision 1.192
diff -u -r1.192 ruleset.c
--- server/ruleset.c    31 Aug 2004 04:40:50 -0000      1.192
+++ server/ruleset.c    3 Sep 2004 04:28:43 -0000
@@ -865,25 +865,16 @@
     free(def_vblist);
   }
   
-  /* Tech requirement is used to flag removed unit_types, which
-     we might want to know for other fields.  After this we
-     can use unit_type_exists()
-  */
   unit_type_iterate(i) {
     u = &unit_types[i];
     u->tech_requirement = lookup_tech(file, sec[i], "tech_req",
-                                     FALSE, filename, u->name);
+                                     TRUE, filename, u->name);
   } unit_type_iterate_end;
   
   unit_type_iterate(i) {
     u = &unit_types[i];
-    if (unit_type_exists(i)) {
-      u->obsoleted_by = lookup_unit_type(file, sec[i],
-                                        "obsolete_by", FALSE, filename, 
u->name);
-    } else {
-      (void) section_file_lookup(file, "%s.obsolete_by", sec[i]); /* unused */
-      u->obsoleted_by = -1;
-    }
+    u->obsoleted_by = lookup_unit_type(file, sec[i], "obsolete_by",
+                                      FALSE, filename, u->name);
   } unit_type_iterate_end;
 
   /* main stats: */
@@ -1014,20 +1005,12 @@
 
   /* Some more consistency checking: */
   unit_type_iterate(i) {
-    if (unit_type_exists(i)) {
-      u = &unit_types[i];
-      if (!tech_exists(u->tech_requirement)) {
-       freelog(LOG_ERROR,
-               "unit_type \"%s\" depends on removed tech \"%s\" (%s)",
-               u->name, advances[u->tech_requirement].name, filename);
-       u->tech_requirement = A_LAST;
-      }
-      if (u->obsoleted_by!=-1 && !unit_type_exists(u->obsoleted_by)) {
-       freelog(LOG_ERROR,
-               "unit_type \"%s\" obsoleted by removed unit \"%s\" (%s)",
-               u->name, unit_types[u->obsoleted_by].name, filename);
-       u->obsoleted_by = -1;
-      }
+    u = &unit_types[i];
+    if (!tech_exists(u->tech_requirement)) {
+      freelog(LOG_ERROR,
+             "unit_type \"%s\" depends on removed tech \"%s\" (%s)",
+             u->name, advances[u->tech_requirement].name, filename);
+      u->tech_requirement = A_LAST;
     }
   } unit_type_iterate_end;
 
Index: server/savegame.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/savegame.c,v
retrieving revision 1.183
diff -u -r1.183 savegame.c
--- server/savegame.c   3 Sep 2004 01:21:03 -0000       1.183
+++ server/savegame.c   3 Sep 2004 04:28:44 -0000
@@ -1145,7 +1145,7 @@
       }
 
       if ((pwl->wlefs[i] <= WEF_END) || (pwl->wlefs[i] >= WEF_LAST) ||
-         ((pwl->wlefs[i] == WEF_UNIT) && !unit_type_exists(pwl->wlids[i])) ||
+         pwl->wlefs[i] == WEF_UNIT ||
          ((pwl->wlefs[i] == WEF_IMPR) && !improvement_exists(pwl->wlids[i]))) {
        pwl->wlefs[i] = WEF_END;
        pwl->wlids[i] = 0;
@@ -1184,7 +1184,7 @@
        name = old_unit_type_name(id-68);
        pwl->wlefs[i] = WEF_UNIT;
        pwl->wlids[i] = find_unit_type_by_name_orig(name);
-       end = !unit_type_exists(pwl->wlids[i]);
+       end = (pwl->wlids[i] < 0 || pwl->wlids[i] >= game.num_unit_types);
       } else {                         /* must be an improvement id */
        name = old_impr_type_name(id);
        pwl->wlefs[i] = WEF_IMPR;