From f0c56346d98a385608f33d5a0a3ca7391d20d1d1 Mon Sep 17 00:00:00 2001
From: Enno Rehling <enno@eressea.de>
Date: Fri, 23 May 2008 09:25:41 +0000
Subject: [PATCH] http://eressea.upb.de/mantis/view.php?id=1431 "buildings and
 ships are leaking memory" - remove_building and remove_ship work like their
 region/unit counterparts

---
 src/common/gamecode/economy.c | 64 +++++++++++++++++------------------
 src/common/gamecode/laws.c    |  2 +-
 src/common/gamecode/randenc.c | 50 +++++++++++++--------------
 src/common/gamecode/spy.c     |  2 +-
 src/common/kernel/battle.c    |  2 +-
 src/common/kernel/build.c     |  4 +--
 src/common/kernel/building.c  | 38 ++++++++++++++++++---
 src/common/kernel/building.h  |  5 ++-
 src/common/kernel/magic.c     | 20 +++++------
 src/common/kernel/move.c      | 17 +++++-----
 src/common/kernel/region.c    | 10 ++----
 src/common/kernel/ship.c      | 50 +++++++++++++++++++--------
 src/common/kernel/ship.h      |  5 ++-
 src/common/modules/wormhole.c | 21 ++++++------
 src/common/spells/spells.c    | 51 ++++++++++++----------------
 src/common/util/lists.c       | 25 --------------
 src/common/util/lists.h       |  2 --
 src/eressea/lua/building.cpp  | 18 +++++++---
 18 files changed, 206 insertions(+), 180 deletions(-)

diff --git a/src/common/gamecode/economy.c b/src/common/gamecode/economy.c
index 166a0d89f..1a21d6b0c 100644
--- a/src/common/gamecode/economy.c
+++ b/src/common/gamecode/economy.c
@@ -978,41 +978,41 @@ maintain(building * b, boolean first)
 static void
 gebaeude_stuerzt_ein(region * r, building * b)
 {
-	unit *u;
-	int n, i;
-	int opfer = 0;
-	int road = 0;
-	struct message * msg;
+  unit *u;
+  int n, i;
+  int opfer = 0;
+  int road = 0;
+  struct message * msg;
 
-	for (u = r->units; u; u = u->next) {
-		if (u->building == b) {
-			int loss = 0;
+  for (u = r->units; u; u = u->next) {
+    if (u->building == b) {
+      int loss = 0;
 
-			fset(u->faction, FFL_MARK);
-			freset(u, UFL_OWNER);
-			leave(r,u);
-			n = u->number;
-			for (i = 0; i < n; i++) {
-				if (rng_double() >= COLLAPSE_SURVIVAL) {
-					++loss;
-				}
-			}
-			scale_number(u, u->number - loss);
-			opfer += loss;
-		}
-	}
+      fset(u->faction, FFL_MARK);
+      freset(u, UFL_OWNER);
+      leave(r,u);
+      n = u->number;
+      for (i = 0; i < n; i++) {
+        if (rng_double() >= COLLAPSE_SURVIVAL) {
+          ++loss;
+        }
+      }
+      scale_number(u, u->number - loss);
+      opfer += loss;
+    }
+  }
 
-	msg = msg_message("buildingcrash", "region building opfer road", r, b, opfer, road);
-	add_message(&r->msgs, msg);
-	for (u=r->units; u; u=u->next) {
-		faction * f = u->faction;
-		if (fval(f, FFL_MARK)) {
-			freset(u->faction, FFL_MARK);
-			add_message(&f->msgs, msg);
-		}
-	}
-	msg_release(msg);
-	destroy_building(b);
+  msg = msg_message("buildingcrash", "region building opfer road", r, b, opfer, road);
+  add_message(&r->msgs, msg);
+  for (u=r->units; u; u=u->next) {
+    faction * f = u->faction;
+    if (fval(f, FFL_MARK)) {
+      freset(u->faction, FFL_MARK);
+      add_message(&f->msgs, msg);
+    }
+  }
+  msg_release(msg);
+  remove_building(&r->buildings, b);
 }
 
 void
diff --git a/src/common/gamecode/laws.c b/src/common/gamecode/laws.c
index 5feb5dc0b..cc6810293 100644
--- a/src/common/gamecode/laws.c
+++ b/src/common/gamecode/laws.c
@@ -2485,7 +2485,7 @@ sinkships(region * r)
       damage_ship(sh, 0.05);
     }
     if (sh->damage >= sh->size * DAMAGE_SCALE) {
-      destroy_ship(sh);
+      remove_ship(shp, sh);
     }
     if (*shp==sh) shp=&sh->next;
   }
diff --git a/src/common/gamecode/randenc.c b/src/common/gamecode/randenc.c
index 0f8d0f230..0fb0ccdb9 100644
--- a/src/common/gamecode/randenc.c
+++ b/src/common/gamecode/randenc.c
@@ -427,7 +427,6 @@ void
 chaos(region * r)
 {
   unit *u = NULL, *u2;
-  building *b, *b2;
 
   if (rng_int() % 100 < 8) {
     switch (rng_int() % 3) {
@@ -474,7 +473,9 @@ chaos(region * r)
             while (sh) {
               ship * nsh = sh->next;
               damage_ship(sh, 0.50);
-              if (sh->damage >= sh->size * DAMAGE_SCALE) destroy_ship(sh);
+              if (sh->damage >= sh->size * DAMAGE_SCALE) {
+                remove_ship(&sh->region->ships, sh);
+              }
               sh = nsh;
             }
 
@@ -487,10 +488,8 @@ chaos(region * r)
             }
             ADDMSG(&r->msgs, msg_message("tidalwave", "region", r));
 
-            for (b = rbuildings(r); b;) {
-              b2 = b->next;
-              destroy_building(b);
-              b = b2;
+            while (r->buildings) {
+              remove_building(&r->buildings, r->buildings);
             }
             terraform(r, T_OCEAN);
           }
@@ -760,7 +759,6 @@ melt_iceberg(region *r)
 {
 	attrib *a;
 	unit *u;
-	building *b, *b2;
 
 	for (u=r->units; u; u=u->next) freset(u->faction, FFL_SELECT);
 	for (u=r->units; u; u=u->next) if (!fval(u->faction, FFL_SELECT)) {
@@ -773,10 +771,9 @@ melt_iceberg(region *r)
 	if (a) a_remove(&r->attribs, a);
 
 	/* Gebäude löschen */
-	for (b = rbuildings(r); b; b = b2) {
-		b2 = b->next;
-		destroy_building(b);
-	}
+    while (r->buildings) {
+      remove_building(&r->buildings, r->buildings);
+    }
 
 	/* in Ozean wandeln */
 	terraform(r, T_OCEAN);
@@ -875,7 +872,7 @@ move_iceberg(region *r)
               ADDMSG(&u->faction->msgs, msg_message("overrun_by_iceberg_des", 
                 "ship", sh));
             }
-						destroy_ship(sh);
+            remove_ship(&sh->region->ships, sh);
           } else if (u!=NULL) {
             ADDMSG(&u->faction->msgs, msg_message("overrun_by_iceberg", 
               "ship", sh));
@@ -985,7 +982,7 @@ godcurse(void)
             unit * u = shipowner(sh);
             if (u) ADDMSG(&u->faction->msgs,
               msg_message("godcurse_destroy_ship", "ship", sh));
-            destroy_ship(sh);
+            remove_ship(&sh->region->ships, sh);
           }
           sh = shn;
         }
@@ -1122,11 +1119,10 @@ void
 randomevents(void)
 {
 #if KARMA_MODULE
-	faction *f;
+  faction *f;
 #endif /* KARMA_MODULE */
-	region *r;
-	building *b, *b2;
-	unit *u;
+  region *r;
+  unit *u;
 
   icebergs();
   godcurse();
@@ -1191,14 +1187,16 @@ randomevents(void)
   /* Monumente zerfallen, Schiffe verfaulen */
 
   for (r = regions; r; r = r->next) {
-    for (b = rbuildings(r); b; b = b2) {
-      b2 = b->next;
+    building ** blist = &r->buildings;
+    while (*blist) {
+      building * b = *blist;
       if (fval(b->type, BTF_DECAY) && !buildingowner(r, b)) {
         b->size -= max(1, (b->size * 20) / 100);
         if (b->size == 0) {
-          destroy_building(b);
+          remove_building(blist, r->buildings);
         }
       }
+      if (*blist==b) blist=&b->next;
     }
   }
 
@@ -1213,7 +1211,7 @@ randomevents(void)
               "unit region", u, r));
             u_setfaction(u, get_monsters());
           }
-        }
+      }
     }
   }
 
@@ -1226,7 +1224,7 @@ randomevents(void)
         for(u = f->units; u; u=u->nextF) {
           if (rng_int()%100 < 2*level) {
             ADDMSG(&u->faction->msgs,
-                   msg_message("becomewere", "unit region", u, u->region));
+              msg_message("becomewere", "unit region", u, u->region));
             fset(u, UFL_WERE);
           }
         }
@@ -1245,16 +1243,16 @@ randomevents(void)
     if (!i) continue;
     chaoscounts(r, -(int) (i * ((double) (rng_int() % 10)) / 100.0));
   }
-  
+
 #ifdef HERBS_ROT
   /* Kräuter verrotten */
   for (r = regions; r; r = r->next) {
     for (u = r->units; u; u=u->next) {
       item **itmp = &u->items, *hbag = *i_find(&u->items, olditemtype[I_SACK_OF_CONSERVATION]);
       int rot_chance = HERBROTCHANCE;
-      
+
       if (hbag) rot_chance = (HERBROTCHANCE*2)/5;
-      
+
       while (*itmp) {
         item * itm = *itmp;
         int n = itm->number;
@@ -1270,7 +1268,7 @@ randomevents(void)
     }
   }
 #endif
-  
+
   dissolve_units();
   check_split();
 #if KARMA_MODULE
diff --git a/src/common/gamecode/spy.c b/src/common/gamecode/spy.c
index 4a28851de..9c79284a2 100644
--- a/src/common/gamecode/spy.c
+++ b/src/common/gamecode/spy.c
@@ -566,7 +566,7 @@ sink_ship(region * r, ship * sh, const char *name, char spy, unit * saboteur)
   if (enemy_discovers_spy_msg) msg_release(enemy_discovers_spy_msg);
   if (sink_msg) msg_release(sink_msg);
   /* finally, get rid of the ship */
-  destroy_ship(sh);
+  remove_ship(&sh->region->ships, sh);
   vset_destroy(&informed);
   vset_destroy(&survivors);
 }
diff --git a/src/common/kernel/battle.c b/src/common/kernel/battle.c
index 74308410f..3b4da4c16 100644
--- a/src/common/kernel/battle.c
+++ b/src/common/kernel/battle.c
@@ -2572,7 +2572,7 @@ aftermath(battle * b)
       ship * sh = *sp;
       freset(sh, SF_DAMAGED);
       if (sh->damage >= sh->size * DAMAGE_SCALE) {
-        destroy_ship(sh);
+        remove_ship(sp, sh);
       }
       if (*sp==sh) sp=&sh->next;
     }
diff --git a/src/common/kernel/build.c b/src/common/kernel/build.c
index b0e0f6cee..ffc060047 100644
--- a/src/common/kernel/build.c
+++ b/src/common/kernel/build.c
@@ -384,7 +384,7 @@ destroy_cmd(unit * u, struct order * ord)
       ADDMSG(&u->faction->msgs, msg_message("destroy",
         "building unit", b, u));
       con = b->type->construction;
-      destroy_building(b);
+      remove_building(&r->buildings, b);
     } else {
       /* partial destroy */
       b->size -= n;
@@ -411,7 +411,7 @@ destroy_cmd(unit * u, struct order * ord)
       ADDMSG(&u->faction->msgs, msg_message("shipdestroy",
         "unit region ship", u, r, sh));
       con = sh->type->construction;
-      destroy_ship(sh);
+      remove_ship(&sh->region->ships, sh);
     } else {
       /* partial destroy */
       sh->size -= (sh->type->construction->maxsize * n)/100;
diff --git a/src/common/kernel/building.c b/src/common/kernel/building.c
index def3e82ff..bb4b375aa 100644
--- a/src/common/kernel/building.c
+++ b/src/common/kernel/building.c
@@ -394,7 +394,7 @@ read_building_reference(struct building ** b, struct storage * store)
     *b = findbuilding(var.i);
     if (*b==NULL) ur_add(var, (void**)b, resolve_building);
     return AT_READ_OK;
-  }
+    }
 }
 
 void
@@ -452,8 +452,13 @@ new_building(const struct building_type * btype, region * r, const struct locale
   return b;
 }
 
+static building * deleted_buildings;
+
+/** remove a building from the region.
+ * remove_building lets units leave the building
+ */
 void
-destroy_building(building * b)
+remove_building(building ** blist, building * b)
 {
   unit *u;
   direction_t d;
@@ -467,7 +472,9 @@ destroy_building(building * b)
     bt_tunnel = bt_find("tunnel");
   }
 
-  if (!bfindhash(b->no)) return;
+  assert(bfindhash(b->no));
+
+  handle_event(b->attribs, "destroy", b);
   for (u=b->region->units; u; u=u->next) {
     if (u->building == b) leave(b->region, u);
   }
@@ -486,8 +493,29 @@ destroy_building(building * b)
   }
 
   /* Stattdessen nur aus Liste entfernen, aber im Speicher halten. */
-  choplist(&b->region->buildings, b);
-  handle_event(b->attribs, "destroy", b);
+  while (*blist && *blist!=b) blist = &(*blist)->next;
+  *blist = b->next;
+  b->region = NULL;
+  b->next = deleted_buildings;
+  deleted_buildings = b;
+}
+
+void
+free_building(building * b)
+{
+  while (b->attribs) a_remove (&b->attribs, b->attribs);
+  free(b->name);
+  free(b->display);
+  free(b);
+}
+
+void
+free_buildings(void)
+{
+  while (deleted_buildings) {
+    building * b = deleted_buildings;
+    deleted_buildings = b->next;
+  }
 }
 
 extern struct attrib_type at_icastle;
diff --git a/src/common/kernel/building.h b/src/common/kernel/building.h
index ac1d1866c..e44f49620 100644
--- a/src/common/kernel/building.h
+++ b/src/common/kernel/building.h
@@ -123,7 +123,10 @@ int buildingeffsize(const building * b, boolean img);
 void bhash(struct building * b);
 void bunhash(struct building * b);
 int buildingcapacity(const struct building * b);
-void destroy_building(struct building * b);
+
+extern void remove_building(struct building * *blist, struct building * b);
+extern void free_building(struct building * b);
+extern void free_buildings(void);
 
 const struct building_type * findbuildingtype(const char * name, const struct locale * lang);
 
diff --git a/src/common/kernel/magic.c b/src/common/kernel/magic.c
index a049f4c8e..183d01f36 100644
--- a/src/common/kernel/magic.c
+++ b/src/common/kernel/magic.c
@@ -144,17 +144,17 @@ a_writeicastle(const attrib * a, struct storage * store)
 static int
 a_ageicastle(struct attrib * a)
 {
-	icastle_data * data = (icastle_data*)a->data.v;
-	if (data->time<=0) {
-		building * b = data->building;
-		region * r = b->region;
+  icastle_data * data = (icastle_data*)a->data.v;
+  if (data->time<=0) {
+    building * b = data->building;
+    region * r = b->region;
     ADDMSG(&r->msgs, msg_message("icastle_dissolve", "building", b));
-		/* destroy_building lets units leave the building */
-		destroy_building(b);
-		return 0;
-	}
-	else data->time--;
-	return 1;
+    /* remove_building lets units leave the building */
+    remove_building(&r->buildings, b);
+    return 0;
+  }
+  else data->time--;
+  return 1;
 }
 
 static void
diff --git a/src/common/kernel/move.c b/src/common/kernel/move.c
index 80c353b92..451e50707 100644
--- a/src/common/kernel/move.c
+++ b/src/common/kernel/move.c
@@ -481,23 +481,24 @@ static ship *
 do_maelstrom(region *r, unit *u)
 {
   int damage;
+  ship * sh = u->ship;
 
   damage = rng_int()%150 - eff_skill(u, SK_SAILING, r)*5;
 
   if (damage <= 0) {
-    return u->ship;
+    return sh;
   }
 
   damage_ship(u->ship, 0.01*damage);
 
-  if (u->ship->damage >= u->ship->size * DAMAGE_SCALE) {
+  if (sh->damage >= sh->size * DAMAGE_SCALE) {
     ADDMSG(&u->faction->msgs, msg_message("entermaelstrom",
-      "region ship damage sink", r, u->ship, damage, 1));
-    destroy_ship(u->ship);
+      "region ship damage sink", r, sh, damage, 1));
+    remove_ship(&sh->region->ships, sh);
     return NULL;
   }
   ADDMSG(&u->faction->msgs, msg_message("entermaelstrom",
-    "region ship damage sink", r, u->ship, damage, 0));
+    "region ship damage sink", r, sh, damage, 0));
   return u->ship;
 }
 
@@ -776,7 +777,7 @@ drifting_ships(region * r)
 
         damage_ship(sh, 0.02);
         if (sh->damage>=sh->size * DAMAGE_SCALE) {
-          destroy_ship(sh);
+          remove_ship(shp, sh);
         }
       }
 
@@ -1782,7 +1783,7 @@ sail(unit * u, order * ord, boolean move_on_land, region_list **routep)
 
   if (sh->damage>=sh->size * DAMAGE_SCALE) {
     ADDMSG(&f->msgs, msg_message("shipsink", "ship", sh));
-    destroy_ship(sh);
+    remove_ship(&sh->region->ships, sh);
     sh = NULL;
   }
 
@@ -2322,7 +2323,7 @@ destroy_damaged_ships(void)
 		for(sh=r->ships;sh;) {
 			shn = sh->next;
 			if (sh->damage>=sh->size * DAMAGE_SCALE) {
-				destroy_ship(sh);
+				remove_ship(&sh->region->ships, sh);
 			}
 			sh = shn;
 		}
diff --git a/src/common/kernel/region.c b/src/common/kernel/region.c
index 2156c12ce..0468aee80 100644
--- a/src/common/kernel/region.c
+++ b/src/common/kernel/region.c
@@ -951,19 +951,15 @@ free_region(region * r)
   while (r->buildings) {
     building * b = r->buildings;
     r->buildings = b->next;
-    bunhash(b);
-    free(b->name);
-    free(b->display);
-    free(b);
+    bunhash(b); /* must be done here, because remove_building does it, and wasn't called */
+    free_building(b);
   }
 
   while (r->ships) {
     ship * s = r->ships;
     r->ships = s->next;
     sunhash(s);
-    free(s->name);
-    free(s->display);
-    free(s);
+    free_ship(s);
   }
 
   free(r);
diff --git a/src/common/kernel/ship.c b/src/common/kernel/ship.c
index 5bfc514c5..11229decd 100644
--- a/src/common/kernel/ship.c
+++ b/src/common/kernel/ship.c
@@ -24,6 +24,7 @@
 #include "skill.h"
 
 /* util includes */
+#include <util/attrib.h>
 #include <util/base36.h>
 #include <util/event.h>
 #include <util/language.h>
@@ -162,32 +163,33 @@ captain(ship *sh, region *r)
 }
 
 /* Alte Schiffstypen: */
-
+static ship * deleted_ships;
 
 ship *
 new_ship(const ship_type * stype, const struct locale * lang, region * r)
 {
-	static char buffer[7 + IDSIZE + 1];
-	ship *sh = (ship *) calloc(1, sizeof(ship));
+  static char buffer[7 + IDSIZE + 1];
+  ship *sh = (ship *) calloc(1, sizeof(ship));
 
-	sh->no = newcontainerid();
-	sh->coast = NODIRECTION;
-	sh->type = stype;
-	sh->region = r;
+  sh->no = newcontainerid();
+  sh->coast = NODIRECTION;
+  sh->type = stype;
+  sh->region = r;
 
-	sprintf(buffer, "%s %s", LOC(lang, stype->name[0]), shipid(sh));
-	sh->name = strdup(buffer);
-	shash(sh);
+  sprintf(buffer, "%s %s", LOC(lang, stype->name[0]), shipid(sh));
+  sh->name = strdup(buffer);
+  shash(sh);
   addlist(&r->ships, sh);
-	return sh;
+  return sh;
 }
 
 void
-destroy_ship(ship * sh)
+remove_ship(ship ** slist, ship * sh)
 {
   region * r = sh->region;
   unit * u = r->units;
 
+  handle_event(sh->attribs, "destroy", sh);
   while (u) {
     if (u->ship == sh) {
       leave_ship(u);
@@ -195,8 +197,28 @@ destroy_ship(ship * sh)
     u = u->next;
   }
   sunhash(sh);
-  choplist(&r->ships, sh);
-  handle_event(sh->attribs, "destroy", sh);
+  while (*slist && *slist!=sh) slist = &(*slist)->next;
+  *slist = sh->next;
+  sh->next = deleted_ships;
+  deleted_ships = sh;
+}
+
+void
+free_ship(ship * s)
+{
+  while (s->attribs) a_remove(&s->attribs, s->attribs);
+  free(s->name);
+  free(s->display);
+  free(s);
+}
+
+void
+free_ships(void)
+{
+  while (deleted_ships) {
+    ship * s = deleted_ships;
+    deleted_ships = s->next;
+  }
 }
 
 const char *
diff --git a/src/common/kernel/ship.h b/src/common/kernel/ship.h
index f5d1bc5cd..af8bc6e72 100644
--- a/src/common/kernel/ship.h
+++ b/src/common/kernel/ship.h
@@ -97,7 +97,10 @@ extern const struct ship_type * findshiptype(const char *s, const struct locale
 extern void register_ships(void);
 extern void write_ship_reference(const struct ship * sh, struct storage * store);
 
-extern void destroy_ship(struct ship * s);
+extern void remove_ship(struct ship ** slist, struct ship * s);
+extern void free_ship(struct ship * s);
+extern void free_ships(void);
+
 
 #ifdef __cplusplus
 }
diff --git a/src/common/modules/wormhole.c b/src/common/modules/wormhole.c
index 7eee84fba..939aface1 100644
--- a/src/common/modules/wormhole.c
+++ b/src/common/modules/wormhole.c
@@ -23,10 +23,12 @@
 #include <kernel/plane.h>
 #include <kernel/region.h>
 #include <kernel/unit.h>
+#include <kernel/version.h>
 
 /* util includes */
 #include <util/attrib.h>
 #include <util/rng.h>
+#include <util/resolve.h>
 #include <util/storage.h>
 
 /* libc includes */
@@ -51,7 +53,7 @@ cmp_age(const void * v1, const void *v2)
 
 typedef struct wormhole_data {
   building * entry;
-  building * exit;
+  region * exit;
 } wormhole_data;
 
 static void
@@ -80,10 +82,10 @@ wormhole_age(struct attrib * a)
       if (u->number>maxtransport || has_limited_skills(u)) {
         m = msg_message("wormhole_requirements", "unit region", u, u->region);
       } else if (data->exit!=NULL) {
-        move_unit(u, data->exit->region, NULL);
+        move_unit(u, data->exit, NULL);
         maxtransport -= u->number;
-        m = msg_message("wormhole_exit", "unit region", u, data->exit->region);
-        add_message(&data->exit->region->msgs, m);
+        m = msg_message("wormhole_exit", "unit region", u, data->exit);
+        add_message(&data->exit->msgs, m);
       }
       if (m!=NULL) {
         add_message(&u->faction->msgs, m);
@@ -92,11 +94,8 @@ wormhole_age(struct attrib * a)
     }
   }
 
-  /* it's important that destroy_building doesn't change b->region, because
-   * otherwise the tunnel would no longer be bi-directional after this */
-  destroy_building(data->entry);
+  remove_building(&r->buildings, data->entry);
   ADDMSG(&r->msgs, msg_message("wormhole_dissolve", "region", r));
-  assert(data->entry->region==r);
 
   /* age returns 0 if the attribute needs to be removed, !=0 otherwise */
   return -1;
@@ -140,8 +139,10 @@ make_wormhole(const building_type * bt_wormhole, region * r1, region * r2)
   attrib * a2 = a_add(&b2->attribs, a_new(&at_wormhole));
   wormhole_data * d1 = (wormhole_data*)a1->data.v;
   wormhole_data * d2 = (wormhole_data*)a2->data.v;
-  d1->entry = d2->exit = b1;
-  d2->entry = d1->exit = b2;
+  d1->entry = b1;
+  d2->entry = b2;
+  d1->exit = b2->region;
+  d2->exit = b1->region;
   b1->size = bt_wormhole->maxsize;
   b2->size = bt_wormhole->maxsize;
   ADDMSG(&r1->msgs, msg_message("wormhole_appear", "region", r1));
diff --git a/src/common/spells/spells.c b/src/common/spells/spells.c
index 81c3d5bea..d95ac5b28 100644
--- a/src/common/spells/spells.c
+++ b/src/common/spells/spells.c
@@ -1604,7 +1604,6 @@ destroy_all_roads(region *r)
 static int
 sp_great_drought(castorder *co)
 {
-  building *b, *b2;
   unit *u;
   boolean terraform = false;
   region *r = co->rt;
@@ -1664,10 +1663,8 @@ sp_great_drought(castorder *co)
               set_number(u, 0);
             }
           }
-          for (b = r->buildings; b;) {
-            b2 = b->next;
-            destroy_building(b);
-            b = b2;
+          while (r->buildings) {
+            remove_building(&r->buildings, r->buildings);
           }
         }
         break;
@@ -2271,39 +2268,28 @@ static int
 sp_earthquake(castorder *co)
 {
   int kaputt;
-  building *burg;
-  unit *u;
   region *r = co->rt;
   unit *mage = co->magician.u;
   int cast_level = co->level;
   message * msg;
+  building **blist = &r->buildings;
 
-  for (burg = r->buildings; burg; burg = burg->next) {
-    if (burg->size == 0 )
-      continue;
+  while (*blist) {
+    building * burg = *blist;
 
-    /* Schutzzauber */
-    if (is_cursed(burg->attribs, C_MAGICWALLS, 0))
-      continue;
-
-    /* Magieresistenz */
-    if (target_resists_magic(mage, burg, TYP_BUILDING, 0))
-      continue;
-
-    kaputt = min(10 * cast_level, burg->size / 4);
-    kaputt = max(kaputt, 1);
-    burg->size -= kaputt;
-    if (burg->size == 0 ) {
-      /* alle Einheiten hinausbefördern */
-      for(u = r->units; u; u = u->next ) {
-        if (u->building == burg ) {
-          u->building = 0;
-          freset(u, UFL_OWNER);
+    if (burg->size != 0 && !is_cursed(burg->attribs, C_MAGICWALLS, 0)) {
+      /* Magieresistenz */
+      if (!target_resists_magic(mage, burg, TYP_BUILDING, 0)) {
+        kaputt = min(10 * cast_level, burg->size / 4);
+        kaputt = max(kaputt, 1);
+        burg->size -= kaputt;
+        if (burg->size == 0) {
+          /* TODO: sollten die Insassen nicht Schaden nehmen? */
+          remove_building(blist, burg);
         }
       }
-      /* TODO: sollten die Insassen nicht Schaden nehmen? */
-      destroy_building(burg);
     }
+    if (*blist==burg) blist=&burg->next;
   }
 
   /* melden, 1x pro Partei */
@@ -3198,11 +3184,16 @@ dc_read_compat(struct attrib * a, storage * store)
   variant var;
   int duration = store->r_int(store);
   double strength = store->r_flt(store);
+  short rx, ry;
 
   var.i = store->r_id(store);
   u = findunit(var.i);
 
-  read_region_reference(&r, store);
+  /* this only affects really old data. no need to change: */
+  rx = store->r_int(store);
+  ry = store->r_int(store);
+  r = findregion(rx, ry);
+
   if (r!=NULL) {
     variant effect;
     curse * c;
diff --git a/src/common/util/lists.c b/src/common/util/lists.c
index 671464a20..9bbfcbb4f 100644
--- a/src/common/util/lists.c
+++ b/src/common/util/lists.c
@@ -87,16 +87,6 @@ insertlist(void_list ** l, void_list * p)
 
 }
 
-void
-promotelist(void *l, void *p)
-{
-
-	/* remove entry p from list l; insert p again at the beginning of l */
-
-	choplist(l, p);
-	insertlist((void_list **)l, (void_list *)p);
-}
-
 void
 removelist(void *l, void *p)
 {
@@ -124,21 +114,6 @@ freelist(void *p1)
 	}
 }
 
-void
-invert_list(void * heap)
-{
-	void_list * x = NULL;
-	void_list * m = *(void_list**)heap;
-	while (m)
-	{
-		void_list * d = m;
-		m = m->next;
-		d->next = x;
-		x = d;
-	}
-	*(void **)heap = x;
-}
-
 unsigned int
 listlen(void *l)
 {
diff --git a/src/common/util/lists.h b/src/common/util/lists.h
index 1dfdd5c4b..557ce0553 100644
--- a/src/common/util/lists.h
+++ b/src/common/util/lists.h
@@ -39,7 +39,6 @@ typedef struct void_list {
 void addlist(void *l1, void *p1);
 void choplist(void * l, void * p);
 void translist(void *l1, void *l2, void *p);
-void promotelist(void *l, void *p);
 #ifndef MALLOCDBG
 void freelist(void *p1);
 void removelist(void *l, void *p);
@@ -49,7 +48,6 @@ void removelist(void *l, void *p);
 #endif
 
 unsigned int listlen(void *l);
-void invert_list(void * heap);
 #define addlist2(l, p)       (*l = p, l = &p->next)
 
 void *listelem(void *l, int n);
diff --git a/src/eressea/lua/building.cpp b/src/eressea/lua/building.cpp
index 272de8bdd..878469829 100644
--- a/src/eressea/lua/building.cpp
+++ b/src/eressea/lua/building.cpp
@@ -118,11 +118,21 @@ building_getregion(const building& b)
 }
 
 static void
-building_setregion(building& b, region& r)
+building_setregion(building& bld, region& r)
 {
-	choplist(&b.region->buildings, &b);
-  addlist(&r.buildings, &b);
-  b.region = &r;
+  building * b = &bld;
+  building ** blist = &b->region->buildings;
+  while (*blist && *blist!=b) {
+    blist = &(*blist)->next;
+  }
+  *blist = b->next;
+  b->next = NULL;
+
+  blist = &r.buildings;
+  while (*blist && *blist!=b) blist = &(*blist)->next;
+  *blist = b;
+
+  b->region = &r;
 }
 
 static std::ostream&