# HG changeset patch
# User yexo <yexo@openttd.org>
# Date 1283550651 0
# Node ID 86c457462b3575df2195eebfb1d858b0a63d9079
# Parent  db77f9f00373fe53b117f9544ff9a54af6ef2ee6
(svn r20729) -Fix [FS#4107]: assert when overbuilding object

diff --git a/src/command.cpp b/src/command.cpp
--- a/src/command.cpp
+++ b/src/command.cpp
@@ -27,6 +27,7 @@
 #include "company_base.h"
 #include "signal_func.h"
 #include "core/backup_type.hpp"
+#include "object_base.h"
 
 #include "table/strings.h"
 
@@ -402,6 +403,7 @@
 
 	/* only execute the test call if it's toplevel, or we're not execing. */
 	if (_docommand_recursive == 1 || !(flags & DC_EXEC) ) {
+		if (_docommand_recursive == 1) _cleared_object_areas.Clear();
 		SetTownRatingTestMode(true);
 		res = proc(tile, flags & ~DC_EXEC, p1, p2, text);
 		SetTownRatingTestMode(false);
@@ -424,6 +426,7 @@
 
 	/* Execute the command here. All cost-relevant functions set the expenses type
 	 * themselves to the cost object at some point */
+	if (_docommand_recursive == 1) _cleared_object_areas.Clear();
 	res = proc(tile, flags, p1, p2, text);
 	if (res.Failed()) {
 error:
@@ -610,6 +613,7 @@
 	CommandCost res;
 	if (estimate_only || !skip_test) {
 		/* Test the command. */
+		_cleared_object_areas.Clear();
 		SetTownRatingTestMode(true);
 		res = proc(tile, flags, p1, p2, text);
 		SetTownRatingTestMode(false);
@@ -649,6 +653,7 @@
 
 	/* Actually try and execute the command. If no cost-type is given
 	 * use the construction one */
+	_cleared_object_areas.Clear();
 	CommandCost res2 = proc(tile, flags | DC_EXEC, p1, p2, text);
 
 	if (cmd_id == CMD_COMPANY_CTRL) {
diff --git a/src/core/smallvec_type.hpp b/src/core/smallvec_type.hpp
--- a/src/core/smallvec_type.hpp
+++ b/src/core/smallvec_type.hpp
@@ -13,6 +13,7 @@
 #define SMALLVEC_TYPE_HPP
 
 #include "alloc_func.hpp"
+#include "mem_func.hpp"
 #include "math_func.hpp"
 
 /**
@@ -35,6 +36,12 @@
 public:
 	SmallVector() : data(NULL), items(0), capacity(0) { }
 
+	template<uint X>
+	SmallVector(const SmallVector<T, X> &other) : data(NULL), items(0), capacity(0)
+	{
+		MemCpyT<T>(this->Append(other.Length()), other.Begin(), other.Length());
+	}
+
 	~SmallVector()
 	{
 		free(this->data);
diff --git a/src/landscape.cpp b/src/landscape.cpp
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -29,6 +29,7 @@
 #include "landscape_type.h"
 #include "animated_tile_func.h"
 #include "core/random_func.hpp"
+#include "object_base.h"
 
 #include "table/sprites.h"
 
@@ -603,6 +604,9 @@
  */
 CommandCost CmdLandscapeClear(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 {
+	for (uint i = 0; i < _cleared_object_areas.Length(); i++) {
+		if (_cleared_object_areas[i].Intersects(TileArea(tile, 1, 1))) return CommandCost();
+	}
 	return _tile_type_procs[GetTileType(tile)]->clear_tile_proc(tile, flags);
 }
 
@@ -634,7 +638,9 @@
 
 	for (int x = sx; x <= ex; ++x) {
 		for (int y = sy; y <= ey; ++y) {
+			SmallVector<TileArea, 1> object_areas = _cleared_object_areas;
 			CommandCost ret = DoCommand(TileXY(x, y), 0, 0, flags & ~DC_EXEC, CMD_LANDSCAPE_CLEAR);
+			_cleared_object_areas = object_areas;
 			if (ret.Failed()) {
 				last_error = ret;
 				continue;
diff --git a/src/object_base.h b/src/object_base.h
--- a/src/object_base.h
+++ b/src/object_base.h
@@ -17,6 +17,7 @@
 #include "tilearea_type.h"
 #include "town_type.h"
 #include "date_type.h"
+#include "core/smallvec_type.hpp"
 
 typedef Pool<Object, ObjectID, 64, 64000> ObjectPool;
 extern ObjectPool _object_pool;
@@ -86,4 +87,6 @@
 #define FOR_ALL_OBJECTS_FROM(var, start) FOR_ALL_ITEMS_FROM(Object, object_index, var, start)
 #define FOR_ALL_OBJECTS(var) FOR_ALL_OBJECTS_FROM(var, 0)
 
+extern SmallVector<TileArea, 4> _cleared_object_areas;
+
 #endif /* OBJECT_BASE_H */
diff --git a/src/object_cmd.cpp b/src/object_cmd.cpp
--- a/src/object_cmd.cpp
+++ b/src/object_cmd.cpp
@@ -342,6 +342,8 @@
 	delete o;
 }
 
+SmallVector<TileArea, 4> _cleared_object_areas;
+
 static CommandCost ClearTile_Object(TileIndex tile, DoCommandFlag flags)
 {
 	ObjectType type = GetObjectType(tile);
@@ -351,6 +353,8 @@
 	Object *o = Object::GetByTile(tile);
 	TileArea ta = o->location;
 
+	*_cleared_object_areas.Append() = ta;
+
 	CommandCost cost(EXPENSES_CONSTRUCTION, spec->GetClearCost() * ta.w * ta.h / 5);
 	if (spec->flags & OBJECT_FLAG_CLEAR_INCOME) cost.MultiplyCost(-1); // They get an income!