Merge branch 'extra_large_maps-sx' into jgrpp

Conflicts:
	src/saveload/saveload.cpp

projects/openttd_vs140.vcxproj

@@ -886,6 +886,8 @@
     <ClCompile Include="..\src\saveload\town_sl.cpp" />
     <ClCompile Include="..\src\saveload\vehicle_sl.cpp" />
     <ClCompile Include="..\src\saveload\waypoint_sl.cpp" />
+    <ClInclude Include="..\src\saveload\extended_ver_sl.h" />
+    <ClCompile Include="..\src\saveload\extended_ver_sl.cpp" />
     <ClInclude Include="..\src\table\airport_defaults.h" />
     <ClInclude Include="..\src\table\airport_movement.h" />
     <ClInclude Include="..\src\table\airporttile_ids.h" />

projects/openttd_vs140.vcxproj.filters

@@ -1836,6 +1836,12 @@
     <ClCompile Include="..\src\saveload\waypoint_sl.cpp">
       <Filter>Save/Load handlers</Filter>
     </ClCompile>
+    <ClInclude Include="..\src\saveload\extended_ver_sl.h">
+      <Filter>Save/Load handlers</Filter>
+    </ClInclude>
+    <ClCompile Include="..\src\saveload\extended_ver_sl.cpp">
+      <Filter>Save/Load handlers</Filter>
+    </ClCompile>
     <ClInclude Include="..\src\table\airport_defaults.h">
       <Filter>Tables</Filter>
     </ClInclude>

src/genworld_gui.cpp

@@ -20,6 +20,7 @@
 #include "sound_func.h"
 #include "fios.h"
 #include "string_func.h"
+#include "gui.h"
 #include "widgets/dropdown_type.h"
 #include "widgets/dropdown_func.h"
 #include "querystring_gui.h"
@@ -281,12 +282,37 @@ static void LandscapeGenerationCallback(Window *w, bool confirmed)
 	if (confirmed) StartGeneratingLandscape((GenerateLandscapeWindowMode)w->window_number);
 }
 
-static DropDownList *BuildMapsizeDropDown()
+/**
+ * Check if map size set lies in allowed boundaries.
+ * @param print_warning If set to true, messagebox with warning is printed out if size is outside limits.
+ * @return true if size is ok, false otherwise.
+ */
+static bool CheckMapSize(bool print_warning = true)
+{
+	uint64 tiles = 1ULL << (_settings_newgame.game_creation.map_x + _settings_newgame.game_creation.map_y);
+
+	if (_settings_newgame.game_creation.map_x + _settings_newgame.game_creation.map_y > MAX_MAP_TILES_BITS) {
+		if (print_warning) {
+			SetDParam(0, MAX_MAP_TILES);
+			SetDParam(1, tiles);
+			ShowErrorMessage(STR_MAPGEN_TOO_MANY_TILES_MESSAGE, INVALID_STRING_ID, WL_ERROR, 0, 0);
+		}
+		return false;
+	}
+	return true;
+}
+
+/**
+ * Build dropdown list with map sizes
+ * Dimension selected in the other dropdown is used to suggest which choices are 'valid'
+ * @param other_dimension Dimension specified by the second dropdown.
+ */
+static DropDownList *BuildMapsizeDropDown(int other_dimension)
 {
 	DropDownList *list = new DropDownList();
 
 	for (uint i = MIN_MAP_SIZE_BITS; i <= MAX_MAP_SIZE_BITS; i++) {
-		DropDownListParamStringItem *item = new DropDownListParamStringItem(STR_JUST_INT, i, false);
+		DropDownListParamStringItem *item = new DropDownListParamStringItem((i + other_dimension > MAX_MAP_TILES_BITS) ? STR_RED_INT : STR_JUST_INT, i, false);
 		item->SetParam(0, 1 << i);
 		*list->Append() = item;
 	}
@@ -314,6 +340,14 @@ struct GenerateLandscapeWindow : public Window {
 	char name[64];
 	GenerateLandscapeWindowMode mode;
 
+	void SetDropDownColor()
+	{
+		/* Draw sizes in mapsize selection dropdowns in red if too large size is selected */
+		bool mapsize_valid = CheckMapSize(false);
+		this->GetWidget<NWidgetCore>(WID_GL_MAPSIZE_X_PULLDOWN)->widget_data = mapsize_valid ? STR_JUST_INT : STR_RED_INT;
+		this->GetWidget<NWidgetCore>(WID_GL_MAPSIZE_Y_PULLDOWN)->widget_data = mapsize_valid ? STR_JUST_INT : STR_RED_INT;
+	}
+
 	GenerateLandscapeWindow(WindowDesc *desc, WindowNumber number = 0) : Window(desc)
 	{
 		this->InitNested(number);
@@ -322,6 +356,8 @@ struct GenerateLandscapeWindow : public Window {
 
 		this->mode = (GenerateLandscapeWindowMode)this->window_number;
 
+		SetDropDownColor();
+
 		/* Disable town, industry and trees in SE */
 		this->SetWidgetDisabledState(WID_GL_TOWN_PULLDOWN,     _game_mode == GM_EDITOR);
 		this->SetWidgetDisabledState(WID_GL_INDUSTRY_PULLDOWN, _game_mode == GM_EDITOR);
@@ -538,11 +574,11 @@ struct GenerateLandscapeWindow : public Window {
 				break;
 
 			case WID_GL_MAPSIZE_X_PULLDOWN: // Mapsize X
-				ShowDropDownList(this, BuildMapsizeDropDown(), _settings_newgame.game_creation.map_x, WID_GL_MAPSIZE_X_PULLDOWN);
+				ShowDropDownList(this, BuildMapsizeDropDown(_settings_newgame.game_creation.map_y), _settings_newgame.game_creation.map_x, WID_GL_MAPSIZE_X_PULLDOWN);
 				break;
 
 			case WID_GL_MAPSIZE_Y_PULLDOWN: // Mapsize Y
-				ShowDropDownList(this, BuildMapsizeDropDown(), _settings_newgame.game_creation.map_y, WID_GL_MAPSIZE_Y_PULLDOWN);
+				ShowDropDownList(this, BuildMapsizeDropDown(_settings_newgame.game_creation.map_x), _settings_newgame.game_creation.map_y, WID_GL_MAPSIZE_Y_PULLDOWN);
 				break;
 
 			case WID_GL_TOWN_PULLDOWN: // Number of towns
@@ -554,6 +590,7 @@ struct GenerateLandscapeWindow : public Window {
 				break;
 
 			case WID_GL_GENERATE_BUTTON: { // Generate
+				if (!CheckMapSize()) break;
 				/* Get rotated map size. */
 				uint map_x;
 				uint map_y;
@@ -716,8 +753,14 @@ struct GenerateLandscapeWindow : public Window {
 	virtual void OnDropdownSelect(int widget, int index)
 	{
 		switch (widget) {
-			case WID_GL_MAPSIZE_X_PULLDOWN:     _settings_newgame.game_creation.map_x = index; break;
-			case WID_GL_MAPSIZE_Y_PULLDOWN:     _settings_newgame.game_creation.map_y = index; break;
+			case WID_GL_MAPSIZE_X_PULLDOWN:
+				_settings_newgame.game_creation.map_x = index;
+				SetDropDownColor();
+				break;
+			case WID_GL_MAPSIZE_Y_PULLDOWN:
+				_settings_newgame.game_creation.map_y = index;
+				SetDropDownColor();
+				break;
 			case WID_GL_TREE_PULLDOWN:          _settings_newgame.game_creation.tree_placer = index; break;
 			case WID_GL_RIVER_PULLDOWN:         _settings_newgame.game_creation.amount_of_rivers = index; break;
 			case WID_GL_SMOOTHNESS_PULLDOWN:    _settings_newgame.game_creation.tgen_smoothness = index;  break;
@@ -881,10 +924,19 @@ struct CreateScenarioWindow : public Window
 {
 	uint widget_id;
 
+	void SetDropDownColor()
+	{
+		/* Draw sizes in mapsize selection dropdowns in red if too large size is selected */
+		bool mapsize_valid = CheckMapSize(false);
+		this->GetWidget<NWidgetCore>(WID_CS_MAPSIZE_X_PULLDOWN)->widget_data = mapsize_valid ? STR_JUST_INT : STR_RED_INT;
+		this->GetWidget<NWidgetCore>(WID_CS_MAPSIZE_Y_PULLDOWN)->widget_data = mapsize_valid ? STR_JUST_INT : STR_RED_INT;
+	}
+
 	CreateScenarioWindow(WindowDesc *desc, WindowNumber window_number) : Window(desc)
 	{
 		this->InitNested(window_number);
 		this->LowerWidget(_settings_newgame.game_creation.landscape + WID_CS_TEMPERATE);
+		SetDropDownColor();
 	}
 
 	virtual void SetStringParameters(int widget) const
@@ -908,6 +960,8 @@ struct CreateScenarioWindow : public Window
 		}
 	}
 
+
+
 	virtual void OnPaint()
 	{
 		this->SetWidgetDisabledState(WID_CS_START_DATE_DOWN,       _settings_newgame.game_creation.starting_year <= MIN_YEAR);
@@ -961,18 +1015,20 @@ struct CreateScenarioWindow : public Window
 				break;
 
 			case WID_CS_MAPSIZE_X_PULLDOWN: // Mapsize X
-				ShowDropDownList(this, BuildMapsizeDropDown(), _settings_newgame.game_creation.map_x, WID_CS_MAPSIZE_X_PULLDOWN);
+				ShowDropDownList(this, BuildMapsizeDropDown(_settings_newgame.game_creation.map_y), _settings_newgame.game_creation.map_x, WID_CS_MAPSIZE_X_PULLDOWN);
 				break;
 
 			case WID_CS_MAPSIZE_Y_PULLDOWN: // Mapsize Y
-				ShowDropDownList(this, BuildMapsizeDropDown(), _settings_newgame.game_creation.map_y, WID_CS_MAPSIZE_Y_PULLDOWN);
+				ShowDropDownList(this, BuildMapsizeDropDown(_settings_newgame.game_creation.map_x), _settings_newgame.game_creation.map_y, WID_CS_MAPSIZE_Y_PULLDOWN);
 				break;
 
 			case WID_CS_EMPTY_WORLD: // Empty world / flat world
+				if (!CheckMapSize()) break;
 				StartGeneratingLandscape(GLWM_SCENARIO);
 				break;
 
 			case WID_CS_RANDOM_WORLD: // Generate
+				if (!CheckMapSize()) break;
 				ShowGenerateLandscape();
 				break;
 
@@ -1031,6 +1087,8 @@ struct CreateScenarioWindow : public Window
 			case WID_CS_MAPSIZE_X_PULLDOWN: _settings_newgame.game_creation.map_x = index; break;
 			case WID_CS_MAPSIZE_Y_PULLDOWN: _settings_newgame.game_creation.map_y = index; break;
 		}
+		SetDropDownColor();
+
 		this->SetDirty();
 	}
 

src/landscape.cpp

@@ -723,12 +723,13 @@ void RunTileLoop()
 	 * shift register (LFSR). This allows a deterministic pseudorandom ordering, but
 	 * still with minimal state and fast iteration. */
 
-	/* Maximal length LFSR feedback terms, from 12-bit (for 64x64 maps) to 24-bit (for 4096x4096 maps).
+	/* Maximal length LFSR feedback terms, from 12-bit (for 64x64 maps) to 28-bit (for 16kx16k maps).
 	 * Extracted from http://www.ece.cmu.edu/~koopman/lfsr/ */
 	static const uint32 feedbacks[] = {
-		0xD8F, 0x1296, 0x2496, 0x4357, 0x8679, 0x1030E, 0x206CD, 0x403FE, 0x807B8, 0x1004B2, 0x2006A8, 0x4004B2, 0x800B87
+		0xD8F, 0x1296, 0x2496, 0x4357, 0x8679, 0x1030E, 0x206CD, 0x403FE, 0x807B8, 0x1004B2, 0x2006A8,
+		0x4004B2, 0x800B87, 0x10004F3, 0x200072D, 0x40006AE, 0x80009E3,
 	};
-	assert_compile(lengthof(feedbacks) == 2 * MAX_MAP_SIZE_BITS - 2 * MIN_MAP_SIZE_BITS + 1);
+	assert_compile(lengthof(feedbacks) == MAX_MAP_TILES_BITS - 2 * MIN_MAP_SIZE_BITS + 1);
 	const uint32 feedback = feedbacks[MapLogX() + MapLogY() - 2 * MIN_MAP_SIZE_BITS];
 
 	/* We update every tile every 256 ticks, so divide the map size by 2^8 = 256 */

src/lang/english.txt

@@ -3070,6 +3070,7 @@ STR_MAPGEN_HEIGHTMAP_ROTATION                                   :{BLACK}Heightma
 STR_MAPGEN_HEIGHTMAP_NAME                                       :{BLACK}Heightmap name:
 STR_MAPGEN_HEIGHTMAP_SIZE_LABEL                                 :{BLACK}Size:
 STR_MAPGEN_HEIGHTMAP_SIZE                                       :{ORANGE}{NUM} x {NUM}
+STR_MAPGEN_TOO_MANY_TILES_MESSAGE                               :{YELLOW}Too many tiles in map. Maximum number of tiles is {NUM}, you have selected {NUM}
 
 STR_MAPGEN_MAX_HEIGHTLEVEL_QUERY_CAPT                           :{WHITE}Change maximum map height
 STR_MAPGEN_SNOW_LINE_QUERY_CAPT                                 :{WHITE}Change snow line height
@@ -5482,6 +5483,7 @@ STR_DATE_LONG_SMALL                                             :{TINY_FONT}{BLA
 STR_TINY_GROUP                                                  :{TINY_FONT}{GROUP}
 STR_BLACK_INT                                                   :{BLACK}{NUM}
 STR_ORANGE_INT                                                  :{ORANGE}{NUM}
+STR_RED_INT                                                     :{RED}{NUM}
 STR_WHITE_SIGN                                                  :{WHITE}{SIGN}
 STR_TINY_BLACK_STATION                                          :{TINY_FONT}{BLACK}{STATION}
 STR_BLACK_STRING                                                :{BLACK}{STRING}

src/map.cpp

@@ -40,17 +40,19 @@ TileExtended *_me = NULL; ///< Extended Tiles of the map
  */
 void AllocateMap(uint size_x, uint size_y)
 {
+	DEBUG(map, 2, "Min/max map size %d/%d, max map tiles %d", MIN_MAP_SIZE, MAX_MAP_SIZE, MAX_MAP_TILES);
+	DEBUG(map, 1, "Allocating map of size %dx%d", size_x, size_y);
+
 	/* Make sure that the map size is within the limits and that
 	 * size of both axes is a power of 2. */
-	if (!IsInsideMM(size_x, MIN_MAP_SIZE, MAX_MAP_SIZE + 1) ||
-			!IsInsideMM(size_y, MIN_MAP_SIZE, MAX_MAP_SIZE + 1) ||
+	if (size_x * size_y > MAX_MAP_TILES ||
+			size_x < MIN_MAP_SIZE ||
+			size_y < MIN_MAP_SIZE ||
 			(size_x & (size_x - 1)) != 0 ||
 			(size_y & (size_y - 1)) != 0) {
 		error("Invalid map size");
 	}
 
-	DEBUG(map, 1, "Allocating map of size %dx%d", size_x, size_y);
-
 	_map_log_x = FindFirstBit(size_x);
 	_map_log_y = FindFirstBit(size_y);
 	_map_size_x = size_x;

src/map_type.h

@@ -62,9 +62,11 @@ struct TileIndexDiffC {
 
 /** Minimal and maximal map width and height */
 static const uint MIN_MAP_SIZE_BITS = 6;                      ///< Minimal size of map is equal to 2 ^ MIN_MAP_SIZE_BITS
-static const uint MAX_MAP_SIZE_BITS = 12;                     ///< Maximal size of map is equal to 2 ^ MAX_MAP_SIZE_BITS
+static const uint MAX_MAP_SIZE_BITS = 20;                     ///< Maximal size of map is equal to 2 ^ MAX_MAP_SIZE_BITS
+static const uint MAX_MAP_TILES_BITS = 28;                    ///< Maximal number of tiles in a map is equal to 2 ^ MAX_MAP_TILES_BITS.
 static const uint MIN_MAP_SIZE      = 1 << MIN_MAP_SIZE_BITS; ///< Minimal map size = 64
-static const uint MAX_MAP_SIZE      = 1 << MAX_MAP_SIZE_BITS; ///< Maximal map size = 4096
+static const uint MAX_MAP_SIZE      = 1 << MAX_MAP_SIZE_BITS; ///< Maximal map size = 1M
+static const uint MAX_MAP_TILES     = 1 << MAX_MAP_TILES_BITS;///< Maximal number of tiles in a map = 256M (16k x 16k)
 
 /**
  * Approximation of the length of a straight track, relative to a diagonal

src/newgrf_debug_gui.cpp

@@ -56,7 +56,7 @@ NewGrfDebugSpritePicker _newgrf_debug_sprite_picker = { SPM_NONE, NULL, 0, Small
  */
 static inline uint GetFeatureIndex(uint window_number)
 {
-	return GB(window_number, 0, 24);
+	return GB(window_number, 0, 27);
 }
 
 /**
@@ -68,8 +68,8 @@ static inline uint GetFeatureIndex(uint window_number)
  */
 static inline uint GetInspectWindowNumber(GrfSpecFeature feature, uint index)
 {
-	assert((index >> 24) == 0);
-	return (feature << 24) | index;
+	assert((index >> 27) == 0);
+	return (feature << 27) | index;
 }
 
 /**
@@ -246,7 +246,7 @@ struct NIFeature {
  */
 static inline GrfSpecFeature GetFeatureNum(uint window_number)
 {
-	return (GrfSpecFeature)GB(window_number, 24, 8);
+	return (GrfSpecFeature)GB(window_number, 27, 5);
 }
 
 /**
@@ -699,6 +699,7 @@ static WindowDesc _newgrf_inspect_desc(
  */
 void ShowNewGRFInspectWindow(GrfSpecFeature feature, uint index, const uint32 grfid)
 {
+	if (index >= (1 << 27)) return;
 	if (!IsNewGRFInspectable(feature, index)) return;
 
 	WindowNumber wno = GetInspectWindowNumber(feature, index);
@@ -718,6 +719,7 @@ void ShowNewGRFInspectWindow(GrfSpecFeature feature, uint index, const uint32 gr
 void InvalidateNewGRFInspectWindow(GrfSpecFeature feature, uint index)
 {
 	if (feature == GSF_INVALID) return;
+	if (index >= (1 << 27)) return;
 
 	WindowNumber wno = GetInspectWindowNumber(feature, index);
 	InvalidateWindowData(WC_NEWGRF_INSPECT, wno);
@@ -734,6 +736,7 @@ void InvalidateNewGRFInspectWindow(GrfSpecFeature feature, uint index)
 void DeleteNewGRFInspectWindow(GrfSpecFeature feature, uint index)
 {
 	if (feature == GSF_INVALID) return;
+	if (index >= (1 << 27)) return;
 
 	WindowNumber wno = GetInspectWindowNumber(feature, index);
 	DeleteWindowById(WC_NEWGRF_INSPECT, wno);
@@ -755,6 +758,7 @@ void DeleteNewGRFInspectWindow(GrfSpecFeature feature, uint index)
  */
 bool IsNewGRFInspectable(GrfSpecFeature feature, uint index)
 {
+	if (index >= (1 << 27)) return false;
 	const NIFeature *nif = GetFeature(GetInspectWindowNumber(feature, index));
 	if (nif == NULL) return false;
 	return nif->helper->IsInspectable(index);

src/openttd.cpp

@@ -977,6 +977,24 @@ static void MakeNewGameDone()
 	MarkWholeScreenDirty();
 }
 
+/*
+ * Too large size may be stored in settings (especially if switching between between OpenTTD
+ * versions with different map size limits), we have to check if it is valid before generating world.
+ * Simple separate checking of X and Y map sizes is not enough, as their sum is what counts for the limit.
+ * Check the size and decrease the larger of the sizes till the size is in limit.
+ */
+static void FixConfigMapSize()
+{
+	while (_settings_game.game_creation.map_x + _settings_game.game_creation.map_y > MAX_MAP_TILES_BITS) {
+		/* Repeat reducing larger of X/Y dimensions until the map size is within allowable limits */
+		if (_settings_game.game_creation.map_x > _settings_game.game_creation.map_y) {
+			_settings_game.game_creation.map_x--;
+		} else {
+			_settings_game.game_creation.map_y--;
+		}
+	}
+}
+
 static void MakeNewGame(bool from_heightmap, bool reset_settings)
 {
 	_game_mode = GM_NORMAL;
@@ -984,6 +1002,7 @@ static void MakeNewGame(bool from_heightmap, bool reset_settings)
 	ResetGRFConfig(true);
 
 	GenerateWorldSetCallback(&MakeNewGameDone);
+	FixConfigMapSize();
 	GenerateWorld(from_heightmap ? GWM_HEIGHTMAP : GWM_NEWGAME, 1 << _settings_game.game_creation.map_x, 1 << _settings_game.game_creation.map_y, reset_settings);
 }
 
@@ -999,6 +1018,7 @@ static void MakeNewEditorWorld()
 	ResetGRFConfig(true);
 
 	GenerateWorldSetCallback(&MakeNewEditorWorldDone);
+	FixConfigMapSize();
 	GenerateWorld(GWM_EMPTY, 1 << _settings_game.game_creation.map_x, 1 << _settings_game.game_creation.map_y);
 }
 
@@ -1144,6 +1164,7 @@ void SwitchToMode(SwitchMode new_mode)
 		case SM_LOAD_HEIGHTMAP: // Load heightmap from scenario editor
 			SetLocalCompany(OWNER_NONE);
 
+			FixConfigMapSize();
 			GenerateWorld(GWM_HEIGHTMAP, 1 << _settings_game.game_creation.map_x, 1 << _settings_game.game_creation.map_y);
 			MarkWholeScreenDirty();
 			break;
@@ -1186,6 +1207,7 @@ void SwitchToMode(SwitchMode new_mode)
 
 		case SM_GENRANDLAND: // Generate random land within scenario editor
 			SetLocalCompany(OWNER_NONE);
+			FixConfigMapSize();
 			GenerateWorld(GWM_RANDOM, 1 << _settings_game.game_creation.map_x, 1 << _settings_game.game_creation.map_y);
 			/* XXX: set date */
 			MarkWholeScreenDirty();

src/saveload/saveload.cpp

@@ -894,9 +894,20 @@ void SlSetLength(size_t length)
 				case CH_RIFF:
 					/* Ugly encoding of >16M RIFF chunks
 					 * The lower 24 bits are normal
-					 * The uppermost 4 bits are bits 24:27 */
-					assert(length < (1 << 28));
+					 * The uppermost 4 bits are bits 24:27
+					 *
+					 * If we have more than 28 bits, use an extra uint32 and
+					 * signal this using the extended chunk header */
+					assert(length < (1LL << 32));
+					if (length >= (1 << 28)) {
+						/* write out extended chunk header */
+						SlWriteByte(CH_EXT_HDR);
+						SlWriteUint32(static_cast<uint32>(SLCEHF_BIG_RIFF));
+					}
 					SlWriteUint32((uint32)((length & 0xFFFFFF) | ((length >> 24) << 28)));
+					if (length >= (1 << 28)) {
+						SlWriteUint32(length >> 28);
+					}
 					break;
 				case CH_ARRAY:
 					assert(_sl.last_array_index <= _sl.array_index);
@@ -1667,6 +1678,16 @@ void SlAutolength(AutolengthProc *proc, void *arg)
 	if (offs != _sl.dumper->GetSize()) SlErrorCorrupt("Invalid chunk size");
 }
 
+/*
+ * Notes on extended chunk header:
+ *
+ * If the chunk type is CH_EXT_HDR (15), then a u32 flags field follows.
+ * This flag field may define additional fields which follow the flags field in future.
+ * The standard chunk header follows, though it my be modified by the flags field.
+ * At present SLCEHF_BIG_RIFF increases the RIFF size limit to a theoretical 60 bits,
+ * by adding a further u32 field for the high bits after the existing RIFF size field.
+ */
+
 /**
  * Load a chunk of data (eg vehicles, stations, etc.)
  * @param ch The chunkhandler that will be used for the operation
@@ -1680,6 +1701,15 @@ static void SlLoadChunk(const ChunkHandler *ch)
 	_sl.block_mode = m;
 	_sl.obj_len = 0;
 
+	SaveLoadChunkExtHeaderFlags ext_flags = static_cast<SaveLoadChunkExtHeaderFlags>(0);
+	if ((m & 0xF) == CH_EXT_HDR) {
+		ext_flags = static_cast<SaveLoadChunkExtHeaderFlags>(SlReadUint32());
+
+		/* read in real header */
+		m = SlReadByte();
+		_sl.block_mode = m;
+	}
+
 	switch (m) {
 		case CH_ARRAY:
 			_sl.array_index = 0;
@@ -1701,6 +1731,10 @@ static void SlLoadChunk(const ChunkHandler *ch)
 					}
 					len = SlReadUint32();
 				}
+				if (ext_flags & SLCEHF_BIG_RIFF) {
+					len |= SlReadUint32() << 28;
+				}
+
 				_sl.obj_len = len;
 				endoffs = _sl.reader->GetSize() + len;
 				ch->load_proc();
@@ -1726,9 +1760,21 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
 	_sl.block_mode = m;
 	_sl.obj_len = 0;
 
+	SaveLoadChunkExtHeaderFlags ext_flags = static_cast<SaveLoadChunkExtHeaderFlags>(0);
+	if ((m & 0xF) == CH_EXT_HDR) {
+		ext_flags = static_cast<SaveLoadChunkExtHeaderFlags>(SlReadUint32());
+
+		/* read in real header */
+		m = SlReadByte();
+		_sl.block_mode = m;
+	}
+
 	switch (m) {
 		case CH_ARRAY:
 			_sl.array_index = 0;
+			if (ext_flags) {
+				SlErrorCorruptFmt("CH_ARRAY does not take chunk header extension flags: 0x%X", ext_flags);
+			}
 			if (ch && ch->load_check_proc) {
 				ch->load_check_proc();
 			} else {
@@ -1736,6 +1782,9 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
 			}
 			break;
 		case CH_SPARSE_ARRAY:
+			if (ext_flags) {
+				SlErrorCorruptFmt("CH_SPARSE_ARRAY does not take chunk header extension flags: 0x%X", ext_flags);
+			}
 			if (ch && ch->load_check_proc) {
 				ch->load_check_proc();
 			} else {
@@ -1744,6 +1793,9 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
 			break;
 		default:
 			if ((m & 0xF) == CH_RIFF) {
+				if (ext_flags != (ext_flags & SLCEHF_BIG_RIFF)) {
+					SlErrorCorruptFmt("Unknown chunk header extension flags for CH_RIFF: 0x%X", ext_flags);
+				}
 				/* Read length */
 				len = (SlReadByte() << 16) | ((m >> 4) << 24);
 				len += SlReadUint16();
@@ -1752,6 +1804,14 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
 						SlErrorCorrupt("RIFF chunk too large");
 					}
 					len = SlReadUint32();
+					if (ext_flags & SLCEHF_BIG_RIFF) SlErrorCorrupt("XSLFI_RIFF_HEADER_60_BIT and SLCEHF_BIG_RIFF both present");
+				}
+				if (ext_flags & SLCEHF_BIG_RIFF) {
+					uint64 full_len = len | (static_cast<uint64>(SlReadUint32()) << 28);
+					if (full_len >= (1LL << 32)) {
+						SlErrorCorrupt("Chunk size too large: " OTTD_PRINTFHEX64, full_len);
+					}
+					len = static_cast<size_t>(full_len);
 				}
 				_sl.obj_len = len;
 				endoffs = _sl.reader->GetSize() + len;

src/saveload/saveload.h

@@ -99,10 +99,17 @@ enum ChunkType {
 	CH_ARRAY        =  1,
 	CH_SPARSE_ARRAY =  2,
 	CH_TYPE_MASK    =  3,
+	CH_EXT_HDR      = 15, ///< Extended chunk header
 	CH_LAST         =  8, ///< Last chunk in this array.
 	CH_AUTO_LENGTH  = 16,
 };
 
+/** Flags for chunk extended headers */
+enum SaveLoadChunkExtHeaderFlags {
+	SLCEHF_BIG_RIFF           = 1 << 0,  ///< This block uses a 60-bit RIFF chunk size
+};
+DECLARE_ENUM_AS_BIT_SET(SaveLoadChunkExtHeaderFlags)
+
 /**
  * VarTypes is the general bitmasked magic type that tells us
  * certain characteristics about the variable it refers to. For example