Initial stubs for extending the save/load version checking/upgrade code,

with support for tests on individually versioned features as well as
savegame versions.
This is mainly for improved handling of features added to patchpacks.
The current status-quo of picking a random number for the savegame
version when releasing a patch breaks loading of savegames from newer
trunk savegame versions, with or without the same patch applied, as
savegame upgrade code is not run, which can also lead to crashes on load.
Instead don't change the savegame version (but set the high bit to
keep trunk versions away), but instead include the versions of individual
features using a separate mechanism.

source.list

@@ -633,6 +633,8 @@ saveload/subsidy_sl.cpp
 saveload/town_sl.cpp
 saveload/vehicle_sl.cpp
 saveload/waypoint_sl.cpp
+saveload/extended_ver_sl.h
+saveload/extended_ver_sl.cpp
 
 # Tables
 table/airport_defaults.h

src/saveload/extended_ver_sl.cpp

@@ -0,0 +1,105 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file extended_ver_sl.cpp Functions related to handling save/load extended version info. */
+
+#include "../stdafx.h"
+#include "../debug.h"
+#include "extended_ver_sl.h"
+
+#include "../safeguards.h"
+
+uint16 _sl_xv_feature_versions[XSLFI_SIZE];                 ///< array of all known feature types and their current versions
+std::vector<uint32> _sl_xv_discardable_chunk_ids;           ///< list of chunks IDs which we can discard if no chunk loader exists
+
+/**
+ * Extended save/load feature test
+ *
+ * First performs a tradional check on the provided @p savegame_version against @p savegame_version_from and @p savegame_version_to.
+ * Then, if the feature set in the constructor is not XSLFI_NULL, also check than the feature version is inclusively bounded by @p min_version and @p max_version,
+ * and return the combination of the two tests using the operator defined in the constructor.
+ * Otherwise just returns the result of the savegame version test
+ */
+bool ExtendedSaveLoadFeatureTest::IsFeaturePresent(uint16 savegame_version, uint16 savegame_version_from, uint16 savegame_version_to) const
+{
+	bool savegame_version_ok = savegame_version >= savegame_version_from && savegame_version <= savegame_version_to;
+
+	ExtendedSaveLoadFeatureIndex feature = static_cast<ExtendedSaveLoadFeatureIndex>(GB(this->value, 0, 16));
+	if (feature == XSLFI_NULL) return savegame_version_ok;
+
+	uint16 min_version = GB(this->value, 16, 16);
+	uint16 max_version = GB(this->value, 32, 16);
+	ExtendedSaveLoadFeatureTestOperator op = static_cast<ExtendedSaveLoadFeatureTestOperator>(GB(this->value, 48, 16));
+	bool feature_ok = SlXvIsFeaturePresent(feature, min_version, max_version);
+
+	switch (op) {
+		case XSLFTO_OR:
+			return savegame_version_ok || feature_ok;
+
+		case XSLFTO_AND:
+			return savegame_version_ok && feature_ok;
+
+		default:
+			NOT_REACHED();
+			return false;
+	}
+}
+
+/**
+ * Returns true if @p feature is present and has a version inclusively bounded by @p min_version and @p max_version
+ */
+bool SlXvIsFeaturePresent(ExtendedSaveLoadFeatureIndex feature, uint16 min_version, uint16 max_version)
+{
+	assert(feature < XSLFI_SIZE);
+	return _sl_xv_feature_versions[feature] >= min_version && _sl_xv_feature_versions[feature] <= max_version;
+}
+
+/**
+ * Resets all extended feature versions to 0
+ */
+void SlXvResetState()
+{
+	memset(_sl_xv_feature_versions, 0, sizeof(_sl_xv_feature_versions));
+}
+
+/**
+ * Resets all extended feature versions to their currently enabled versions, i.e. versions suitable for saving
+ */
+void SlXvSetCurrentState()
+{
+	extern bool _sl_is_ext_version;
+
+	SlXvResetState();
+	_sl_is_ext_version = true;
+
+	// TODO: set versions for currently enabled features here
+}
+
+/**
+ * Check for "special" savegame versions (i.e. known patchpacks) and set correct savegame version, settings, etc.
+ */
+void SlXvCheckSpecialSavegameVersions()
+{
+	extern uint16 _sl_version;
+
+	// TODO: check for savegame versions
+}
+
+/**
+ * Return true if this chunk has been marked as discardable
+ */
+bool SlXvIsChunkDiscardable(uint32 id)
+{
+	for(size_t i = 0; i < _sl_xv_discardable_chunk_ids.size(); i++) {
+		if (_sl_xv_discardable_chunk_ids[i] == id) {
+			return true;
+		}
+	}
+	return false;
+}

src/saveload/extended_ver_sl.h

@@ -0,0 +1,79 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file extended_ver_sl.h Functions/types related to handling save/load extended version info. */
+
+#ifndef EXTENDED_VER_SL_H
+#define EXTENDED_VER_SL_H
+
+#include "../core/bitmath_func.hpp"
+
+#include <vector>
+
+/**
+ * List of extended features, each feature has its own (16 bit) version
+ */
+enum ExtendedSaveLoadFeatureIndex {
+	XSLFI_NULL                          = 0,      ///< Unused value, to indicate that no extended feature test is in use
+
+	XSLFI_SIZE,                                   ///< Total count of features, including null feature
+};
+
+extern uint16 _sl_xv_feature_versions[XSLFI_SIZE];
+
+/**
+ * Operator to use when combining traditional savegame number test with an extended feature version test
+ */
+enum ExtendedSaveLoadFeatureTestOperator {
+	XSLFTO_OR                           = 0,      ///< Test if traditional savegame version is in bounds OR extended feature is in version bounds
+	XSLFTO_AND                                    ///< Test if traditional savegame version is in bounds AND extended feature is in version bounds
+};
+
+/**
+ * Structure to describe an extended feature version test, and how it combines with a traditional savegame version test
+ */
+struct ExtendedSaveLoadFeatureTest {
+	private:
+	uint64 value;
+
+	public:
+	ExtendedSaveLoadFeatureTest()
+			: value(0) { }
+
+	ExtendedSaveLoadFeatureTest(ExtendedSaveLoadFeatureTestOperator op, ExtendedSaveLoadFeatureIndex feature, uint16 min_version = 1, uint16 max_version = 0xFFFF)
+	{
+		this->value = 0;
+		SB(this->value, 0, 16, feature);
+		SB(this->value, 16, 16, min_version);
+		SB(this->value, 32, 16, max_version);
+		SB(this->value, 48, 16, op);
+	}
+
+	bool IsFeaturePresent(uint16 savegame_version, uint16 savegame_version_from, uint16 savegame_version_to) const;
+};
+
+bool SlXvIsFeaturePresent(ExtendedSaveLoadFeatureIndex feature, uint16 min_version = 1, uint16 max_version = 0xFFFF);
+
+/**
+ * Returns true if @p feature is missing (i.e. has a version of 0)
+ */
+inline bool SlXvIsFeatureMissing(ExtendedSaveLoadFeatureIndex feature)
+{
+	return !SlXvIsFeaturePresent(feature);
+}
+
+void SlXvResetState();
+
+void SlXvSetCurrentState();
+
+void SlXvCheckSpecialSavegameVersions();
+
+bool SlXvIsChunkDiscardable(uint32 id);
+
+#endif /* EXTENDED_VER_SL_H */

src/saveload/saveload.cpp

@@ -48,9 +48,12 @@
 
 #include "saveload_internal.h"
 #include "saveload_filter.h"
+#include "extended_ver_sl.h"
 
 #include "../safeguards.h"
 
+#include <vector>
+
 /*
  * Previous savegame versions, the trunk revision where they were
  * introduced and the released version that had that particular
@@ -264,12 +267,14 @@
  *  194   26881   1.5.x
  */
 extern const uint16 SAVEGAME_VERSION = 194; ///< Current savegame version of OpenTTD.
+const uint16 SAVEGAME_VERSION_EXT = 0x8000; ///< Savegame extension indicator mask
 
 SavegameType _savegame_type; ///< type of savegame we are loading
 
 uint32 _ttdp_version;     ///< version of TTDP savegame (if applicable)
 uint16 _sl_version;       ///< the major savegame version identifier
 byte   _sl_minor_version; ///< the minor savegame version, DO NOT USE!
+bool _sl_is_ext_version;  ///< is this an extended savegame version, with more info in the SLXI chunk?
 char _savegame_format[8]; ///< how to compress savegames
 bool _do_autosave;        ///< are we doing an autosave at the moment?
 
@@ -414,6 +419,7 @@ struct SaveLoadParams {
 static SaveLoadParams _sl; ///< Parameters used for/at saveload.
 
 /* these define the chunks */
+//extern const ChunkHandler _version_ext_chunk_handlers[];
 extern const ChunkHandler _gamelog_chunk_handlers[];
 extern const ChunkHandler _map_chunk_handlers[];
 extern const ChunkHandler _misc_chunk_handlers[];
@@ -450,6 +456,7 @@ extern const ChunkHandler _persistent_storage_chunk_handlers[];
 
 /** Array of all chunks in a savegame, \c NULL terminated. */
 static const ChunkHandler * const _chunk_handlers[] = {
+//	_version_ext_chunk_handlers,            // this should be first, such that it is saved first, as when loading it affects the loading of subsequent chunks
 	_gamelog_chunk_handlers,
 	_map_chunk_handlers,
 	_misc_chunk_handlers,
@@ -503,6 +510,7 @@ static void SlNullPointers()
 	 * during NULLing; especially those that try to get
 	 * pointers from other pools. */
 	_sl_version = SAVEGAME_VERSION;
+	SlXvSetCurrentState();
 
 	DEBUG(sl, 1, "Nulling pointers");
 
@@ -1414,7 +1422,7 @@ static void SlList(void *list, SLRefType conv)
 /** Are we going to save this object or not? */
 static inline bool SlIsObjectValidInSavegame(const SaveLoad *sld)
 {
-	if (_sl_version < sld->version_from || _sl_version > sld->version_to) return false;
+	if (!sld->ext_feature_test.IsFeaturePresent(_sl_version, sld->version_from, sld->version_to)) return false;
 	if (sld->conv & SLF_NOT_IN_SAVE) return false;
 
 	return true;
@@ -1692,7 +1700,7 @@ static void SlLoadChunk(const ChunkHandler *ch)
 /**
  * Load a chunk of data for checking savegames.
  * If the chunkhandler is NULL, the chunk is skipped.
- * @param ch The chunkhandler that will be used for the operation
+ * @param ch The chunkhandler that will be used for the operation, this may be NULL
  */
 static void SlLoadCheckChunk(const ChunkHandler *ch)
 {
@@ -1706,14 +1714,14 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
 	switch (m) {
 		case CH_ARRAY:
 			_sl.array_index = 0;
-			if (ch->load_check_proc) {
+			if (ch && ch->load_check_proc) {
 				ch->load_check_proc();
 			} else {
 				SlSkipArray();
 			}
 			break;
 		case CH_SPARSE_ARRAY:
-			if (ch->load_check_proc) {
+			if (ch && ch->load_check_proc) {
 				ch->load_check_proc();
 			} else {
 				SlSkipArray();
@@ -1726,7 +1734,7 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
 				len += SlReadUint16();
 				_sl.obj_len = len;
 				endoffs = _sl.reader->GetSize() + len;
-				if (ch->load_check_proc) {
+				if (ch && ch->load_check_proc) {
 					ch->load_check_proc();
 				} else {
 					SlSkipBytes(len);
@@ -1840,10 +1848,18 @@ static void SlLoadChunks()
 		DEBUG(sl, 2, "Loading chunk %c%c%c%c", id >> 24, id >> 16, id >> 8, id);
 
 		ch = SlFindChunkHandler(id);
-		if (ch == NULL) SlErrorCorrupt("Unknown chunk type");
+		if (ch == NULL) {
+			if (SlXvIsChunkDiscardable(id)) {
+				DEBUG(sl, 1, "Discarding chunk %c%c%c%c", id >> 24, id >> 16, id >> 8, id);
+				SlLoadCheckChunk(NULL);
+			} else {
+				SlErrorCorrupt("Unknown chunk type");
+			}
+		} else {
 			SlLoadChunk(ch);
 		}
 	}
+}
 
 /** Load all chunks for savegame checking */
 static void SlLoadCheckChunks()
@@ -1855,7 +1871,7 @@ static void SlLoadCheckChunks()
 		DEBUG(sl, 2, "Loading chunk %c%c%c%c", id >> 24, id >> 16, id >> 8, id);
 
 		ch = SlFindChunkHandler(id);
-		if (ch == NULL) SlErrorCorrupt("Unknown chunk type");
+		if (ch == NULL && !SlXvIsChunkDiscardable(id)) SlErrorCorrupt("Unknown chunk type");
 		SlLoadCheckChunk(ch);
 	}
 }
@@ -2511,7 +2527,7 @@ static SaveOrLoadResult SaveFileToDisk(bool threaded)
 		const SaveLoadFormat *fmt = GetSavegameFormat(_savegame_format, &compression);
 
 		/* We have written our stuff to memory, now write it to file! */
-		uint32 hdr[2] = { fmt->tag, TO_BE32(SAVEGAME_VERSION << 16) };
+		uint32 hdr[2] = { fmt->tag, TO_BE32((SAVEGAME_VERSION | SAVEGAME_VERSION_EXT) << 16) };
 		_sl.sf->Write((byte*)hdr, sizeof(hdr));
 
 		_sl.sf = fmt->init_write(_sl.sf, compression);
@@ -2578,6 +2594,7 @@ static SaveOrLoadResult DoSave(SaveFilter *writer, bool threaded)
 	_sl.sf = writer;
 
 	_sl_version = SAVEGAME_VERSION;
+	SlXvSetCurrentState();
 
 	SaveViewportBeforeSaveGame();
 	SlSaveChunks();
@@ -2629,6 +2646,8 @@ static SaveOrLoadResult DoLoad(LoadFilter *reader, bool load_check)
 		_load_check_data.checkable = true;
 	}
 
+	SlXvResetState();
+
 	uint32 hdr[2];
 	if (_sl.lf->Read((byte*)hdr, sizeof(hdr)) != sizeof(hdr)) SlError(STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
 
@@ -2641,6 +2660,8 @@ static SaveOrLoadResult DoLoad(LoadFilter *reader, bool load_check)
 			_sl.lf->Reset();
 			_sl_version = 0;
 			_sl_minor_version = 0;
+			_sl_is_ext_version = false;
+			SlXvResetState();
 
 			/* Try to find the LZO savegame format; it uses 'OTTD' as tag. */
 			fmt = _saveload_formats;
@@ -2663,7 +2684,14 @@ static SaveOrLoadResult DoLoad(LoadFilter *reader, bool load_check)
 			 * Therefore it is loaded, but never saved (or, it saves a 0 in any scenario). */
 			_sl_minor_version = (TO_BE32(hdr[1]) >> 8) & 0xFF;
 
-			DEBUG(sl, 1, "Loading savegame version %d", _sl_version);
+			if (_sl_version & SAVEGAME_VERSION_EXT) {
+				_sl_version &= ~SAVEGAME_VERSION_EXT;
+				_sl_is_ext_version = true;
+			} else {
+				SlXvCheckSpecialSavegameVersions();
+			}
+
+			DEBUG(sl, 1, "Loading savegame version %d%s", _sl_version, _sl_is_ext_version ? " (extended)" : "");
 
 			/* Is the version higher than the current? */
 			if (_sl_version > SAVEGAME_VERSION) SlError(STR_GAME_SAVELOAD_ERROR_TOO_NEW_SAVEGAME);
@@ -2800,6 +2828,8 @@ SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, boo
 			if (!LoadOldSaveGame(filename)) return SL_REINIT;
 			_sl_version = 0;
 			_sl_minor_version = 0;
+			_sl_is_ext_version = false;
+			SlXvResetState();
 			GamelogStartAction(GLAT_LOAD);
 			if (!AfterLoadGame()) {
 				GamelogStopAction();

src/saveload/saveload.h

@@ -14,6 +14,7 @@
 
 #include "../fileio_type.h"
 #include "../strings_type.h"
+#include "extended_ver_sl.h"
 
 /** Save or load result codes. */
 enum SaveOrLoadResult {
@@ -213,6 +214,7 @@ struct SaveLoad {
 	 * that is called to save it. address: global=true, offset: global=false */
 	void *address;       ///< address of variable OR offset of variable in the struct (max offset is 65536)
 	size_t size;         ///< the sizeof size.
+	ExtendedSaveLoadFeatureTest ext_feature_test;  ///< extended feature test
 };
 
 /** Same as #SaveLoad but global variables are used (for better readability); */
@@ -226,9 +228,11 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the field.
  * @param to       Last savegame version that has the field.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  * @note In general, it is better to use one of the SLE_* macros below.
  */
-#define SLE_GENERAL(cmd, base, variable, type, length, from, to) {false, cmd, type, length, from, to, (void*)cpp_offsetof(base, variable), cpp_sizeof(base, variable)}
+#define SLE_GENERAL_X(cmd, base, variable, type, length, from, to, extver) {false, cmd, type, length, from, to, (void*)cpp_offsetof(base, variable), cpp_sizeof(base, variable), extver}
+#define SLE_GENERAL(cmd, base, variable, type, length, from, to) SLE_GENERAL_X(cmd, base, variable, type, length, from, to, {})
 
 /**
  * Storage of a variable in some savegame versions.
@@ -237,8 +241,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the field.
  * @param to       Last savegame version that has the field.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLE_CONDVAR(base, variable, type, from, to) SLE_GENERAL(SL_VAR, base, variable, type, 0, from, to)
+#define SLE_CONDVAR_X(base, variable, type, from, to, extver) SLE_GENERAL_X(SL_VAR, base, variable, type, 0, from, to, extver)
+#define SLE_CONDVAR(base, variable, type, from, to) SLE_CONDVAR_X(base, variable, type, from, to, {})
 
 /**
  * Storage of a reference in some savegame versions.
@@ -247,8 +253,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Type of the reference, a value from #SLRefType.
  * @param from     First savegame version that has the field.
  * @param to       Last savegame version that has the field.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLE_CONDREF(base, variable, type, from, to) SLE_GENERAL(SL_REF, base, variable, type, 0, from, to)
+#define SLE_CONDREF_X(base, variable, type, from, to, extver) SLE_GENERAL_X(SL_REF, base, variable, type, 0, from, to, extver)
+#define SLE_CONDREF(base, variable, type, from, to) SLE_CONDREF_X(base, variable, type, from, to, {})
 
 /**
  * Storage of an array in some savegame versions.
@@ -258,8 +266,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param length   Number of elements in the array.
  * @param from     First savegame version that has the array.
  * @param to       Last savegame version that has the array.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLE_CONDARR(base, variable, type, length, from, to) SLE_GENERAL(SL_ARR, base, variable, type, length, from, to)
+#define SLE_CONDARR_X(base, variable, type, length, from, to, extver) SLE_GENERAL_X(SL_ARR, base, variable, type, length, from, to, extver)
+#define SLE_CONDARR(base, variable, type, length, from, to) SLE_CONDARR_X(base, variable, type, length, from, to, {})
 
 /**
  * Storage of a string in some savegame versions.
@@ -269,8 +279,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param length   Number of elements in the string (only used for fixed size buffers).
  * @param from     First savegame version that has the string.
  * @param to       Last savegame version that has the string.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLE_CONDSTR(base, variable, type, length, from, to) SLE_GENERAL(SL_STR, base, variable, type, length, from, to)
+#define SLE_CONDSTR_X(base, variable, type, length, from, to, extver) SLE_GENERAL_X(SL_STR, base, variable, type, length, from, to, extver)
+#define SLE_CONDSTR(base, variable, type, length, from, to) SLE_CONDSTR_X(base, variable, type, length, from, to, {})
 
 /**
  * Storage of a list in some savegame versions.
@@ -279,8 +291,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the list.
  * @param to       Last savegame version that has the list.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLE_CONDLST(base, variable, type, from, to) SLE_GENERAL(SL_LST, base, variable, type, 0, from, to)
+#define SLE_CONDLST_X(base, variable, type, from, to, extver) SLE_GENERAL_X(SL_LST, base, variable, type, 0, from, to, extver)
+#define SLE_CONDLST(base, variable, type, from, to) SLE_CONDLST_X(base, variable, type, from, to, {})
 
 /**
  * Storage of a variable in every version of a savegame.
@@ -335,17 +349,19 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param length Length of the empty space.
  * @param from   First savegame version that has the empty space.
  * @param to     Last savegame version that has the empty space.
+ * @param extver ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have empty space
  */
-#define SLE_CONDNULL(length, from, to) SLE_CONDARR(NullStruct, null, SLE_FILE_U8 | SLE_VAR_NULL | SLF_NOT_IN_CONFIG, length, from, to)
+#define SLE_CONDNULL_X(length, from, to, extver) SLE_CONDARR_X(NullStruct, null, SLE_FILE_U8 | SLE_VAR_NULL | SLF_NOT_IN_CONFIG, length, from, to, extver)
+#define SLE_CONDNULL(length, from, to) SLE_CONDNULL_X(length, from, to, {})
 
 /** Translate values ingame to different values in the savegame and vv. */
 #define SLE_WRITEBYTE(base, variable, value) SLE_GENERAL(SL_WRITEBYTE, base, variable, 0, 0, value, value)
 
-#define SLE_VEH_INCLUDE() {false, SL_VEH_INCLUDE, 0, 0, 0, SL_MAX_VERSION, NULL, 0}
+#define SLE_VEH_INCLUDE() {false, SL_VEH_INCLUDE, 0, 0, 0, SL_MAX_VERSION, NULL, 0, {}}
-#define SLE_ST_INCLUDE() {false, SL_ST_INCLUDE, 0, 0, 0, SL_MAX_VERSION, NULL, 0}
+#define SLE_ST_INCLUDE() {false, SL_ST_INCLUDE, 0, 0, 0, SL_MAX_VERSION, NULL, 0, {}}
 
 /** End marker of a struct/class save or load. */
-#define SLE_END() {false, SL_END, 0, 0, 0, 0, NULL, 0}
+#define SLE_END() {false, SL_END, 0, 0, 0, 0, NULL, 0, {}}
 
 /**
  * Storage of global simple variables, references (pointers), and arrays.
@@ -354,9 +370,11 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the field.
  * @param to       Last savegame version that has the field.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  * @note In general, it is better to use one of the SLEG_* macros below.
  */
-#define SLEG_GENERAL(cmd, variable, type, length, from, to) {true, cmd, type, length, from, to, (void*)&variable, sizeof(variable)}
+#define SLEG_GENERAL_X(cmd, variable, type, length, from, to, extver) {true, cmd, type, length, from, to, (void*)&variable, sizeof(variable), extver}
+#define SLEG_GENERAL(cmd, variable, type, length, from, to) SLEG_GENERAL_X(cmd, variable, type, length, from, to, {})
 
 /**
  * Storage of a global variable in some savegame versions.
@@ -364,8 +382,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the field.
  * @param to       Last savegame version that has the field.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLEG_CONDVAR(variable, type, from, to) SLEG_GENERAL(SL_VAR, variable, type, 0, from, to)
+#define SLEG_CONDVAR_X(variable, type, from, to, extver) SLEG_GENERAL_X(SL_VAR, variable, type, 0, from, to, extver)
+#define SLEG_CONDVAR(variable, type, from, to) SLEG_CONDVAR_X(variable, type, from, to, {})
 
 /**
  * Storage of a global reference in some savegame versions.
@@ -373,8 +393,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the field.
  * @param to       Last savegame version that has the field.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLEG_CONDREF(variable, type, from, to) SLEG_GENERAL(SL_REF, variable, type, 0, from, to)
+#define SLEG_CONDREF_X(variable, type, from, to, extver) SLEG_GENERAL_X(SL_REF, variable, type, 0, from, to, extver)
+#define SLEG_CONDREF(variable, type, from, to) SLEG_CONDREF_X(variable, type, from, to, {})
 
 /**
  * Storage of a global array in some savegame versions.
@@ -383,8 +405,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param length   Number of elements in the array.
  * @param from     First savegame version that has the array.
  * @param to       Last savegame version that has the array.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLEG_CONDARR(variable, type, length, from, to) SLEG_GENERAL(SL_ARR, variable, type, length, from, to)
+#define SLEG_CONDARR_X(variable, type, length, from, to, extver) SLEG_GENERAL_X(SL_ARR, variable, type, length, from, to, extver)
+#define SLEG_CONDARR(variable, type, length, from, to) SLEG_CONDARR_X(variable, type, length, from, to, {})
 
 /**
  * Storage of a global string in some savegame versions.
@@ -393,8 +417,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param length   Number of elements in the string (only used for fixed size buffers).
  * @param from     First savegame version that has the string.
  * @param to       Last savegame version that has the string.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLEG_CONDSTR(variable, type, length, from, to) SLEG_GENERAL(SL_STR, variable, type, length, from, to)
+#define SLEG_CONDSTR_X(variable, type, length, from, to, extver) SLEG_GENERAL_X(SL_STR, variable, type, length, from, to, extver)
+#define SLEG_CONDSTR(variable, type, length, from, to) SLEG_CONDSTR_X(variable, type, length, from, to, {})
 
 /**
  * Storage of a global list in some savegame versions.
@@ -402,8 +428,10 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param type     Storage of the data in memory and in the savegame.
  * @param from     First savegame version that has the list.
  * @param to       Last savegame version that has the list.
+ * @param extver   ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have the field
  */
-#define SLEG_CONDLST(variable, type, from, to) SLEG_GENERAL(SL_LST, variable, type, 0, from, to)
+#define SLEG_CONDLST_X(variable, type, from, to, extver) SLEG_GENERAL_X(SL_LST, variable, type, 0, from, to, extver)
+#define SLEG_CONDLST(variable, type, from, to) SLEG_CONDLST_X(variable, type, from, to, {})
 
 /**
  * Storage of a global variable in every savegame version.
@@ -445,11 +473,12 @@ typedef SaveLoad SaveLoadGlobVarList;
  * @param length Length of the empty space.
  * @param from   First savegame version that has the empty space.
  * @param to     Last savegame version that has the empty space.
+ * @param extver ExtendedSaveLoadFeatureTest to test (along with from and to) which savegames have empty space
  */
-#define SLEG_CONDNULL(length, from, to) {true, SL_ARR, SLE_FILE_U8 | SLE_VAR_NULL | SLF_NOT_IN_CONFIG, length, from, to, (void*)NULL}
+#define SLEG_CONDNULL(length, from, to) {true, SL_ARR, SLE_FILE_U8 | SLE_VAR_NULL | SLF_NOT_IN_CONFIG, length, from, to, (void*)NULL, {}}
 
 /** End marker of global variables save or load. */
-#define SLEG_END() {true, SL_END, 0, 0, 0, 0, NULL, 0}
+#define SLEG_END() {true, SL_END, 0, 0, 0, 0, NULL, 0, {}}
 
 /**
  * Checks whether the savegame is below \a major.\a minor.
@@ -471,10 +500,10 @@ static inline bool IsSavegameVersionBefore(uint16 major, byte minor = 0)
  * @param version_to   Highest version number that falls within the range.
  * @return Active savegame version falls within the given range.
  */
-static inline bool SlIsObjectCurrentlyValid(uint16 version_from, uint16 version_to)
+static inline bool SlIsObjectCurrentlyValid(uint16 version_from, uint16 version_to, ExtendedSaveLoadFeatureTest ext_feature_test)
 {
 	extern const uint16 SAVEGAME_VERSION;
-	if (SAVEGAME_VERSION < version_from || SAVEGAME_VERSION > version_to) return false;
+	if (!ext_feature_test.IsFeaturePresent(SAVEGAME_VERSION, version_from, version_to)) return false;
 
 	return true;
 }

src/settings.cpp

@@ -486,7 +486,7 @@ static void IniLoadSettings(IniFile *ini, const SettingDesc *sd, const char *grp
 		const SettingDescBase *sdb = &sd->desc;
 		const SaveLoad        *sld = &sd->save;
 
-		if (!SlIsObjectCurrentlyValid(sld->version_from, sld->version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sld->version_from, sld->version_to, sld->ext_feature_test)) continue;
 
 		/* For settings.xx.yy load the settings from [xx] yy = ? */
 		s = strchr(sdb->name, '.');
@@ -585,7 +585,7 @@ static void IniSaveSettings(IniFile *ini, const SettingDesc *sd, const char *grp
 
 		/* If the setting is not saved to the configuration
 		 * file, just continue with the next setting */
-		if (!SlIsObjectCurrentlyValid(sld->version_from, sld->version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sld->version_from, sld->version_to, sld->ext_feature_test)) continue;
 		if (sld->conv & SLF_NOT_IN_CONFIG) continue;
 
 		/* XXX - wtf is this?? (group override?) */
@@ -1381,7 +1381,7 @@ static void HandleOldDiffCustom(bool savegame)
 	for (uint i = 0; i < options_to_load; i++) {
 		const SettingDesc *sd = &_settings[i];
 		/* Skip deprecated options */
-		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) continue;
 		void *var = GetVariableAddress(savegame ? &_settings_game : &_settings_newgame, &sd->save);
 		Write_ValidateSetting(var, sd, (int32)((i == 4 ? 1000 : 1) * _old_diff_custom[i]));
 	}
@@ -1839,7 +1839,7 @@ CommandCost CmdChangeSetting(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 	const SettingDesc *sd = GetSettingDescription(p1);
 
 	if (sd == NULL) return CMD_ERROR;
-	if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) return CMD_ERROR;
+	if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) return CMD_ERROR;
 
 	if (!sd->IsEditable(true)) return CMD_ERROR;
 
@@ -2050,13 +2050,13 @@ const SettingDesc *GetSettingFromName(const char *name, uint *i)
 
 	/* First check all full names */
 	for (*i = 0, sd = _settings; sd->save.cmd != SL_END; sd++, (*i)++) {
-		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) continue;
 		if (strcmp(sd->desc.name, name) == 0) return sd;
 	}
 
 	/* Then check the shortcut variant of the name. */
 	for (*i = 0, sd = _settings; sd->save.cmd != SL_END; sd++, (*i)++) {
-		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) continue;
 		const char *short_name = strchr(sd->desc.name, '.');
 		if (short_name != NULL) {
 			short_name++;
@@ -2067,7 +2067,7 @@ const SettingDesc *GetSettingFromName(const char *name, uint *i)
 	if (strncmp(name, "company.", 8) == 0) name += 8;
 	/* And finally the company-based settings */
 	for (*i = 0, sd = _company_settings; sd->save.cmd != SL_END; sd++, (*i)++) {
-		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) continue;
 		if (strcmp(sd->desc.name, name) == 0) return sd;
 	}
 
@@ -2161,7 +2161,7 @@ void IConsoleListSettings(const char *prefilter)
 	IConsolePrintF(CC_WARNING, "All settings with their current value:");
 
 	for (const SettingDesc *sd = _settings; sd->save.cmd != SL_END; sd++) {
-		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to)) continue;
+		if (!SlIsObjectCurrentlyValid(sd->save.version_from, sd->save.version_to, sd->save.ext_feature_test)) continue;
 		if (prefilter != NULL && strstr(sd->desc.name, prefilter) == NULL) continue;
 		char value[80];
 		const void *ptr = GetVariableAddress(&GetGameSettings(), &sd->save);

src/table/company_settings.ini

@@ -18,8 +18,8 @@ static const SettingDesc _company_settings[] = {
 [post-amble]
 };
 [templates]
-SDT_BOOL = SDT_BOOL($base, $var,        $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_BOOL = SDT_BOOL($base, $var,        $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDT_VAR  =  SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_VAR  =  SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
 SDT_END  = SDT_END()
 
 [defaults]
@@ -34,6 +34,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}
 
 
 

src/table/currency_settings.ini

@@ -11,9 +11,9 @@ static const SettingDesc _currency_settings[] = {
 [post-amble]
 };
 [templates]
-SDT_VAR = SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_VAR = SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDT_CHR = SDT_CHR($base, $var,        $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_CHR = SDT_CHR($base, $var,        $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDT_STR = SDT_STR($base, $var, $type, $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_STR = SDT_STR($base, $var, $type, $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
 SDT_END = SDT_END()
 
 [defaults]
@@ -28,6 +28,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}
 
 
 

src/table/gameopt_settings.ini

@@ -41,13 +41,13 @@ static const SettingDesc _gameopt_settings[] = {
 [post-amble]
 };
 [templates]
-SDTG_GENERAL = SDTG_GENERAL($name, $sdt_cmd, $sle_cmd, $type, $flags, $guiflags, $var, $length, $def, $min, $max, $interval, $full, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_GENERAL = SDTG_GENERAL($name, $sdt_cmd, $sle_cmd, $type, $flags, $guiflags, $var, $length, $def, $min, $max, $interval, $full, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_VAR     =     SDTG_VAR($name,                     $type, $flags, $guiflags, $var,          $def, $min, $max, $interval,        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_VAR     =     SDTG_VAR($name,                     $type, $flags, $guiflags, $var,          $def, $min, $max, $interval,        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDT_NULL     =   SDT_NULL($length, $from, $to),
+SDT_NULL     =   SDT_NULL($length, $from, $to, $extver),
-SDTC_OMANY   = SDTC_OMANY(       $var, $type, $flags, $guiflags, $def,       $max, $full,            $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTC_OMANY   = SDTC_OMANY(       $var, $type, $flags, $guiflags, $def,       $max, $full,            $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTG_OMANY   = SDTG_OMANY($name,       $type, $flags, $guiflags, $var, $def, $max, $full,            $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTG_OMANY   = SDTG_OMANY($name,       $type, $flags, $guiflags, $var, $def, $max, $full,            $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDT_OMANY    =  SDT_OMANY($base, $var, $type, $flags, $guiflags, $def,       $max, $full,            $str, $strhelp, $strval, $proc, $from, $to, $load, $cat),
+SDT_OMANY    =  SDT_OMANY($base, $var, $type, $flags, $guiflags, $def,       $max, $full,            $str, $strhelp, $strval, $proc, $from, $to, $load, $cat, $extver),
-SDT_VAR      =    SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max,        $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDT_VAR      =    SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max,        $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
 SDT_END      = SDT_END()
 
 [defaults]
@@ -62,6 +62,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}
 
 
 

src/table/misc_settings.ini

@@ -15,12 +15,12 @@ static const SettingDescGlobVarList _misc_settings[] = {
 [post-amble]
 };
 [templates]
-SDTG_LIST  =  SDTG_LIST($name, $type, $length, $flags, $guiflags, $var, $def,                               $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_LIST  =  SDTG_LIST($name, $type, $length, $flags, $guiflags, $var, $def,                               $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_MMANY = SDTG_MMANY($name, $type,          $flags, $guiflags, $var, $def,                        $full, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_MMANY = SDTG_MMANY($name, $type,          $flags, $guiflags, $var, $def,                        $full, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_OMANY = SDTG_OMANY($name, $type,          $flags, $guiflags, $var, $def,       $max,            $full, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_OMANY = SDTG_OMANY($name, $type,          $flags, $guiflags, $var, $def,       $max,            $full, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_STR   =   SDTG_STR($name, $type,          $flags, $guiflags, $var, $def,                               $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_STR   =   SDTG_STR($name, $type,          $flags, $guiflags, $var, $def,                               $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_BOOL  =  SDTG_BOOL($name,                 $flags, $guiflags, $var, $def,                               $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_BOOL  =  SDTG_BOOL($name,                 $flags, $guiflags, $var, $def,                               $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_VAR   =   SDTG_VAR($name, $type,          $flags, $guiflags, $var, $def, $min, $max, $interval,        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_VAR   =   SDTG_VAR($name, $type,          $flags, $guiflags, $var, $def, $min, $max, $interval,        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
 SDTG_END   = SDTG_END()
 
 [defaults]
@@ -35,6 +35,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}
 
 
 

src/table/settings.h.preamble

@@ -61,76 +61,76 @@ static size_t ConvertLandscape(const char *value);
 
 /* Macros for various objects to go in the configuration file.
  * This section is for global variables */
-#define SDTG_GENERAL(name, sdt_cmd, sle_cmd, type, flags, guiflags, var, length, def, min, max, interval, full, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_GENERAL(name, sdt_cmd, sle_cmd, type, flags, guiflags, var, length, def, min, max, interval, full, str, strhelp, strval, proc, from, to, cat, extver)\
-	{NSD_GENERAL(name, def, sdt_cmd, guiflags, min, max, interval, full, str, strhelp, strval, proc, NULL, cat), SLEG_GENERAL(sle_cmd, var, type | flags, length, from, to)}
+	{NSD_GENERAL(name, def, sdt_cmd, guiflags, min, max, interval, full, str, strhelp, strval, proc, NULL, cat), SLEG_GENERAL_X(sle_cmd, var, type | flags, length, from, to, extver)}
 
-#define SDTG_VAR(name, type, flags, guiflags, var, def, min, max, interval, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_VAR(name, type, flags, guiflags, var, def, min, max, interval, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(name, SDT_NUMX, SL_VAR, type, flags, guiflags, var, 0, def, min, max, interval, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(name, SDT_NUMX, SL_VAR, type, flags, guiflags, var, 0, def, min, max, interval, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTG_BOOL(name, flags, guiflags, var, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_BOOL(name, flags, guiflags, var, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(name, SDT_BOOLX, SL_VAR, SLE_BOOL, flags, guiflags, var, 0, def, 0, 1, 0, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(name, SDT_BOOLX, SL_VAR, SLE_BOOL, flags, guiflags, var, 0, def, 0, 1, 0, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTG_LIST(name, type, length, flags, guiflags, var, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_LIST(name, type, length, flags, guiflags, var, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(name, SDT_INTLIST, SL_ARR, type, flags, guiflags, var, length, def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(name, SDT_INTLIST, SL_ARR, type, flags, guiflags, var, length, def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTG_STR(name, type, flags, guiflags, var, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_STR(name, type, flags, guiflags, var, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(name, SDT_STRING, SL_STR, type, flags, guiflags, var, lengthof(var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(name, SDT_STRING, SL_STR, type, flags, guiflags, var, lengthof(var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTG_OMANY(name, type, flags, guiflags, var, def, max, full, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_OMANY(name, type, flags, guiflags, var, def, max, full, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(name, SDT_ONEOFMANY, SL_VAR, type, flags, guiflags, var, 0, def, 0, max, 0, full, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(name, SDT_ONEOFMANY, SL_VAR, type, flags, guiflags, var, 0, def, 0, max, 0, full, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTG_MMANY(name, type, flags, guiflags, var, def, full, str, strhelp, strval, proc, from, to, cat)\
+#define SDTG_MMANY(name, type, flags, guiflags, var, def, full, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(name, SDT_MANYOFMANY, SL_VAR, type, flags, guiflags, var, 0, def, 0, 0, 0, full, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(name, SDT_MANYOFMANY, SL_VAR, type, flags, guiflags, var, 0, def, 0, 0, 0, full, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTG_NULL(length, from, to)\
+#define SDTG_NULL(length, from, to, extver)\
-	{{"", NULL, {0}, {0}, 0, 0, 0, NULL, STR_NULL, STR_NULL, STR_NULL, NULL, NULL, SC_NONE}, SLEG_NULL(length, from, to)}
+	{{"", NULL, {0}, {0}, 0, 0, 0, NULL, STR_NULL, STR_NULL, STR_NULL, NULL, NULL, SC_NONE}, SLEG_NULL_X(length, from, to, extver)}
 
 #define SDTG_END() {{NULL, NULL, {0}, {0}, 0, 0, 0, NULL, STR_NULL, STR_NULL, STR_NULL, NULL, NULL, SC_NONE}, SLEG_END()}
 
 /* Macros for various objects to go in the configuration file.
  * This section is for structures where their various members are saved */
-#define SDT_GENERAL(name, sdt_cmd, sle_cmd, type, flags, guiflags, base, var, length, def, min, max, interval, full, str, strhelp, strval, proc, load, from, to, cat)\
+#define SDT_GENERAL(name, sdt_cmd, sle_cmd, type, flags, guiflags, base, var, length, def, min, max, interval, full, str, strhelp, strval, proc, load, from, to, cat, extver)\
-	{NSD_GENERAL(name, def, sdt_cmd, guiflags, min, max, interval, full, str, strhelp, strval, proc, load, cat), SLE_GENERAL(sle_cmd, base, var, type | flags, length, from, to)}
+	{NSD_GENERAL(name, def, sdt_cmd, guiflags, min, max, interval, full, str, strhelp, strval, proc, load, cat), SLE_GENERAL_X(sle_cmd, base, var, type | flags, length, from, to, extver)}
 
-#define SDT_VAR(base, var, type, flags, guiflags, def, min, max, interval, str, strhelp, strval, proc, from, to, cat)\
+#define SDT_VAR(base, var, type, flags, guiflags, def, min, max, interval, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDT_GENERAL(#var, SDT_NUMX, SL_VAR, type, flags, guiflags, base, var, 1, def, min, max, interval, NULL, str, strhelp, strval, proc, NULL, from, to, cat)
+	SDT_GENERAL(#var, SDT_NUMX, SL_VAR, type, flags, guiflags, base, var, 1, def, min, max, interval, NULL, str, strhelp, strval, proc, NULL, from, to, cat, extver)
 
-#define SDT_BOOL(base, var, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDT_BOOL(base, var, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDT_GENERAL(#var, SDT_BOOLX, SL_VAR, SLE_BOOL, flags, guiflags, base, var, 1, def, 0, 1, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat)
+	SDT_GENERAL(#var, SDT_BOOLX, SL_VAR, SLE_BOOL, flags, guiflags, base, var, 1, def, 0, 1, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat, extver)
 
-#define SDT_LIST(base, var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDT_LIST(base, var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDT_GENERAL(#var, SDT_INTLIST, SL_ARR, type, flags, guiflags, base, var, lengthof(((base*)8)->var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat)
+	SDT_GENERAL(#var, SDT_INTLIST, SL_ARR, type, flags, guiflags, base, var, lengthof(((base*)8)->var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat, extver)
 
-#define SDT_STR(base, var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDT_STR(base, var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDT_GENERAL(#var, SDT_STRING, SL_STR, type, flags, guiflags, base, var, lengthof(((base*)8)->var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat)
+	SDT_GENERAL(#var, SDT_STRING, SL_STR, type, flags, guiflags, base, var, lengthof(((base*)8)->var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat, extver)
 
-#define SDT_CHR(base, var, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDT_CHR(base, var, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDT_GENERAL(#var, SDT_STRING, SL_VAR, SLE_CHAR, flags, guiflags, base, var, 1, def, 0, 0, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat)
+	SDT_GENERAL(#var, SDT_STRING, SL_VAR, SLE_CHAR, flags, guiflags, base, var, 1, def, 0, 0, 0, NULL, str, strhelp, strval, proc, NULL, from, to, cat, extver)
 
-#define SDT_OMANY(base, var, type, flags, guiflags, def, max, full, str, strhelp, strval, proc, from, to, load, cat)\
+#define SDT_OMANY(base, var, type, flags, guiflags, def, max, full, str, strhelp, strval, proc, from, to, load, cat, extver)\
-	SDT_GENERAL(#var, SDT_ONEOFMANY, SL_VAR, type, flags, guiflags, base, var, 1, def, 0, max, 0, full, str, strhelp, strval, proc, load, from, to, cat)
+	SDT_GENERAL(#var, SDT_ONEOFMANY, SL_VAR, type, flags, guiflags, base, var, 1, def, 0, max, 0, full, str, strhelp, strval, proc, load, from, to, cat, extver)
 
-#define SDT_MMANY(base, var, type, flags, guiflags, def, full, str, proc, strhelp, strval, from, to, cat)\
+#define SDT_MMANY(base, var, type, flags, guiflags, def, full, str, proc, strhelp, strval, from, to, cat, extver)\
-	SDT_GENERAL(#var, SDT_MANYOFMANY, SL_VAR, type, flags, guiflags, base, var, 1, def, 0, 0, 0, full, str, strhelp, strval, proc, NULL, from, to, cat)
+	SDT_GENERAL(#var, SDT_MANYOFMANY, SL_VAR, type, flags, guiflags, base, var, 1, def, 0, 0, 0, full, str, strhelp, strval, proc, NULL, from, to, cat, extver)
 
-#define SDT_NULL(length, from, to)\
+#define SDT_NULL(length, from, to, extver)\
-	{{"", NULL, {0}, {0}, 0, 0, 0, NULL, STR_NULL, STR_NULL, STR_NULL, NULL, NULL, SC_NONE}, SLE_CONDNULL(length, from, to)}
+	{{"", NULL, {0}, {0}, 0, 0, 0, NULL, STR_NULL, STR_NULL, STR_NULL, NULL, NULL, SC_NONE}, SLE_CONDNULL_X(length, from, to, extver)}
 
 
-#define SDTC_VAR(var, type, flags, guiflags, def, min, max, interval, str, strhelp, strval, proc, from, to, cat)\
+#define SDTC_VAR(var, type, flags, guiflags, def, min, max, interval, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(#var, SDT_NUMX, SL_VAR, type, flags, guiflags, _settings_client.var, 1, def, min, max, interval, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(#var, SDT_NUMX, SL_VAR, type, flags, guiflags, _settings_client.var, 1, def, min, max, interval, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTC_BOOL(var, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDTC_BOOL(var, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(#var, SDT_BOOLX, SL_VAR, SLE_BOOL, flags, guiflags, _settings_client.var, 1, def, 0, 1, 0, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(#var, SDT_BOOLX, SL_VAR, SLE_BOOL, flags, guiflags, _settings_client.var, 1, def, 0, 1, 0, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTC_LIST(var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDTC_LIST(var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(#var, SDT_INTLIST, SL_ARR, type, flags, guiflags, _settings_client.var, lengthof(_settings_client.var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(#var, SDT_INTLIST, SL_ARR, type, flags, guiflags, _settings_client.var, lengthof(_settings_client.var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTC_STR(var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat)\
+#define SDTC_STR(var, type, flags, guiflags, def, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(#var, SDT_STRING, SL_STR, type, flags, guiflags, _settings_client.var, lengthof(_settings_client.var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(#var, SDT_STRING, SL_STR, type, flags, guiflags, _settings_client.var, lengthof(_settings_client.var), def, 0, 0, 0, NULL, str, strhelp, strval, proc, from, to, cat, extver)
 
-#define SDTC_OMANY(var, type, flags, guiflags, def, max, full, str, strhelp, strval, proc, from, to, cat)\
+#define SDTC_OMANY(var, type, flags, guiflags, def, max, full, str, strhelp, strval, proc, from, to, cat, extver)\
-	SDTG_GENERAL(#var, SDT_ONEOFMANY, SL_VAR, type, flags, guiflags, _settings_client.var, 1, def, 0, max, 0, full, str, strhelp, strval, proc, from, to, cat)
+	SDTG_GENERAL(#var, SDT_ONEOFMANY, SL_VAR, type, flags, guiflags, _settings_client.var, 1, def, 0, max, 0, full, str, strhelp, strval, proc, from, to, cat, extver)
 
 #define SDT_END() {{NULL, NULL, {0}, {0}, 0, 0, 0, NULL, STR_NULL, STR_NULL, STR_NULL, NULL, NULL, SC_NONE}, SLE_END()}
 

src/table/settings.ini

@@ -64,19 +64,19 @@ const SettingDesc _settings[] = {
 [post-amble]
 };
 [templates]
-SDTG_BOOL  =  SDTG_BOOL($name,              $flags, $guiflags, $var, $def,                        $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTG_BOOL  =  SDTG_BOOL($name,              $flags, $guiflags, $var, $def,                        $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTG_VAR   =   SDTG_VAR($name,       $type, $flags, $guiflags, $var, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTG_VAR   =   SDTG_VAR($name,       $type, $flags, $guiflags, $var, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTG_OMANY = SDTG_OMANY($name,       $type, $flags, $guiflags, $var, $def,       $max, $full,     $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTG_OMANY = SDTG_OMANY($name,       $type, $flags, $guiflags, $var, $def,       $max, $full,     $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTC_BOOL  =  SDTC_BOOL(       $var,        $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTC_BOOL  =  SDTC_BOOL(       $var,        $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTC_LIST  =  SDTC_LIST(       $var, $type, $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTC_LIST  =  SDTC_LIST(       $var, $type, $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTC_OMANY = SDTC_OMANY(       $var, $type, $flags, $guiflags, $def,             $max, $full,     $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTC_OMANY = SDTC_OMANY(       $var, $type, $flags, $guiflags, $def,             $max, $full,     $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTC_STR   =   SDTC_STR(       $var, $type, $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTC_STR   =   SDTC_STR(       $var, $type, $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDTC_VAR   =   SDTC_VAR(       $var, $type, $flags, $guiflags, $def,       $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDTC_VAR   =   SDTC_VAR(       $var, $type, $flags, $guiflags, $def,       $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDT_BOOL   =   SDT_BOOL($base, $var,        $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDT_BOOL   =   SDT_BOOL($base, $var,        $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDT_OMANY  =  SDT_OMANY($base, $var, $type, $flags, $guiflags, $def,             $max, $full,     $str, $strhelp, $strval, $proc, $from, $to, $load, $cat),
+SDT_OMANY  =  SDT_OMANY($base, $var, $type, $flags, $guiflags, $def,             $max, $full,     $str, $strhelp, $strval, $proc, $from, $to, $load, $cat, $extver),
-SDT_STR    =    SDT_STR($base, $var, $type, $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDT_STR    =    SDT_STR($base, $var, $type, $flags, $guiflags, $def,                              $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDT_VAR    =    SDT_VAR($base, $var, $type, $flags, $guiflags, $def,       $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat),
+SDT_VAR    =    SDT_VAR($base, $var, $type, $flags, $guiflags, $def,       $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to,        $cat, $extver),
-SDT_NULL   =   SDT_NULL($length, $from, $to),
+SDT_NULL   =   SDT_NULL($length, $from, $to, $extver),
 SDT_END    = SDT_END()
 
 [defaults]
@@ -91,6 +91,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}
 
 
 

src/table/win32_settings.ini

@@ -17,8 +17,8 @@ static const SettingDescGlobVarList _win32_settings[] = {
 };
 #endif /* WIN32 */
 [templates]
-SDTG_BOOL = SDTG_BOOL($name,        $flags, $guiflags, $var, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_BOOL = SDTG_BOOL($name,        $flags, $guiflags, $var, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDTG_VAR  =  SDTG_VAR($name, $type, $flags, $guiflags, $var, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDTG_VAR  =  SDTG_VAR($name, $type, $flags, $guiflags, $var, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
 SDTG_END  = SDTG_END()
 
 [defaults]
@@ -33,6 +33,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}
 
 
 

src/table/window_settings.ini

@@ -12,8 +12,8 @@ static const SettingDesc _window_settings[] = {
 [post-amble]
 };
 [templates]
-SDT_BOOL = SDT_BOOL($base, $var,        $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_BOOL = SDT_BOOL($base, $var,        $flags, $guiflags, $def,                        $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
-SDT_VAR  =  SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat),
+SDT_VAR  =  SDT_VAR($base, $var, $type, $flags, $guiflags, $def, $min, $max, $interval, $str, $strhelp, $strval, $proc, $from, $to, $cat, $extver),
 SDT_END  = SDT_END()
 
 [defaults]
@@ -29,6 +29,7 @@ load     = NULL
 from     = 0
 to       = SL_MAX_VERSION
 cat      = SC_ADVANCED
+extver   = {}