# HG changeset patch
# User rubidium <rubidium@openttd.org>
# Date 1265819045 0
# Node ID 38952764f91f2b1f5d2fcfeedc788f5e1a2eeaf8
# Parent  48f9a3fd032ce4c827c9f1bab3506c46c17e50eb
(svn r19081) -Codechange: make it possible to disable compilation of the AI+Squirrel

diff --git a/Doxyfile b/Doxyfile
--- a/Doxyfile
+++ b/Doxyfile
@@ -196,7 +196,7 @@
 SEARCH_INCLUDES        = YES
 INCLUDE_PATH           =
 INCLUDE_FILE_PATTERNS  =
-PREDEFINED             =
+PREDEFINED             = ENABLE_NETWORK ENABLE_AI
 EXPAND_AS_DEFINED      = DEF_COMMAND
 SKIP_FUNCTION_MACROS   = YES
 #---------------------------------------------------------------------------
diff --git a/Makefile.src.in b/Makefile.src.in
--- a/Makefile.src.in
+++ b/Makefile.src.in
@@ -58,7 +58,10 @@
 
 # Make sure endian_target.h is reasable as if it was in the src/ dir
 CFLAGS += -I $(SRC_OBJS_DIR) -I $(LANG_OBJS_DIR)
-CFLAGS_MAKEDEP += -I $(SRC_OBJS_DIR) -I $(LANG_OBJS_DIR) -I $(SCRIPT_SRC_DIR)
+CFLAGS_MAKEDEP += -I $(SRC_OBJS_DIR) -I $(LANG_OBJS_DIR)
+ifdef SCRIPT_SRC_DIR
+	CFLAGS_MAKEDEP += -I $(SCRIPT_SRC_DIR)
+endif
 
 ENDIAN_TARGETS := endian_target.h $(ENDIAN_CHECK)
 
diff --git a/config.lib b/config.lib
--- a/config.lib
+++ b/config.lib
@@ -51,6 +51,7 @@
 	enable_lto="0"
 	enable_dedicated="0"
 	enable_network="1"
+	enable_ai="1"
 	enable_static="1"
 	enable_translator="0"
 	enable_unicode="1"
@@ -122,6 +123,7 @@
 		enable_lto
 		enable_dedicated
 		enable_network
+		enable_ai
 		enable_static
 		enable_translator
 		enable_unicode
@@ -277,6 +279,9 @@
 			--enable-network)             enable_network="2";;
 			--enable-network=*)           enable_network="$optarg";;
 			--disable-network)            enable_network="0";;
+			--enable-ai)                  enable_ai="2";;
+			--enable-ai=*)                enable_ai="$optarg";;
+			--disable-ai)                 enable_ai="0";;
 			--disable-static)             enable_static="0";;
 			--enable-static)              enable_static="2";;
 			--enable-static=*)            enable_static="$optarg";;
@@ -713,6 +718,14 @@
 		log 1 "checking network... disabled"
 	fi
 
+	if [ "$enable_ai" != "0" ]; then
+		log 1 "checking ai... found"
+		SCRIPT_SRC_DIR="$ROOT_DIR/src/3rdparty/squirrel/include"
+	else
+		log 1 "checking ai... disabled"
+		SCRIPT_SRC_DIR=""
+	fi
+
 	if [ "$enable_translator" != "0" ]; then
 		log 1 "checking translator... debug"
 		# -t shows TODO items, normally they are muted
@@ -728,15 +741,6 @@
 		log 1 "checking assert... disabled"
 	fi
 
-	SCRIPT_SRC_DIR="$ROOT_DIR/src/3rdparty/squirrel/include"
-	if [ ! -d "$SCRIPT_SRC_DIR" ]; then
-		log 1 "checking 3rdparty... NOT FOUND"
-		log 1 "ERROR: please make sure you have src/3rdparty/squirrel"
-		log 1 "ERROR: you can find the source at svn://svn.openttd.org/3rdparty/squirrel"
-		exit 1
-	fi
-	log 1 "checking 3rdparty... found"
-
 	pre_detect_with_zlib=$with_zlib
 	detect_zlib
 
@@ -1429,7 +1433,9 @@
 	if [ "$cpu_type" = "64" ] && [ "$enable_universal" = "0" ]; then
 		CFLAGS="$CFLAGS -D_SQ64"
 	fi
-	CFLAGS="$CFLAGS -I$SCRIPT_SRC_DIR"
+	if [ "$enable_ai" != "0" ]; then
+		CFLAGS="$CFLAGS -I$SCRIPT_SRC_DIR -DENABLE_AI"
+	fi
 
 	if [ -n "$png_config" ]; then
 		CFLAGS="$CFLAGS -DWITH_PNG"
diff --git a/configure b/configure
--- a/configure
+++ b/configure
@@ -113,6 +113,7 @@
 		if ($0 == "OS2"         && "'$os'" != "OS2")               { next; }
 		if ($0 == "PSP"         && "'$os'" != "PSP")               { next; }
 		if ($0 == "DEDICATED"   && "'$enable_dedicated'" != "1")   { next; }
+		if ($0 == "AI"          && "'$enable_ai'" == "0")          { next; }
 		if ($0 == "COCOA"       && "'$with_cocoa'" == "0")         { next; }
 		if ($0 == "DOS"         && "'$os'" != "DOS")               { next; }
 		if ($0 == "BEOS"        && "'$os'" != "BEOS" &&
diff --git a/projects/generate b/projects/generate
--- a/projects/generate
+++ b/projects/generate
@@ -40,6 +40,7 @@
 png_config="1"
 os="MSVC"
 enable_dedicated="0"
+enable_ai="1"
 with_cocoa="0"
 enable_directmusic="1"
 with_threads="1"
@@ -94,6 +95,7 @@
 			if ($0 == "PSP"         && "'$os'" != "PSP")               { next; }
 			if ($0 == "DOS"         && "'$os'" != "DOS")               { next; }
 			if ($0 == "DEDICATED"   && "'$enable_dedicated'" != "1")   { next; }
+			if ($0 == "AI"          && "'$enable_ai'" == "0")          { next; }
 			if ($0 == "COCOA"       && "'$with_cocoa'" == "0")         { next; }
 			if ($0 == "BEOS"        && "'$os'" != "BEOS")              { next; }
 			if ($0 == "WIN32"       && "'$os'" != "MINGW" &&
diff --git a/source.list b/source.list
--- a/source.list
+++ b/source.list
@@ -517,6 +517,7 @@
 3rdparty/md5/md5.cpp
 3rdparty/md5/md5.h
 
+#if AI
 # Script
 script/script_info.cpp
 script/script_info.hpp
@@ -697,6 +698,7 @@
 ai/api/ai_vehiclelist.cpp
 ai/api/ai_waypoint.cpp
 ai/api/ai_waypointlist.cpp
+#end
 
 # Blitters
 #if DEDICATED
diff --git a/src/ai/ai.hpp b/src/ai/ai.hpp
--- a/src/ai/ai.hpp
+++ b/src/ai/ai.hpp
@@ -12,6 +12,7 @@
 #ifndef AI_HPP
 #define AI_HPP
 
+#ifdef ENABLE_AI
 #include "api/ai_event_types.hpp"
 #include "../date_type.h"
 #include "../core/string_compare_type.hpp"
@@ -125,4 +126,26 @@
 	static class AIScanner *ai_scanner;
 };
 
+#else /* ENABLE_AI */
+
+#include "../company_type.h"
+
+#define NewEvent(cid, event) nop()
+#define BroadcastNewEvent(...) nop()
+
+class AI {
+public:
+	static void StartNew(CompanyID company, bool rerandomise_ai = true) {}
+	static void Stop(CompanyID company) {}
+	static void Initialize() {}
+	static void Uninitialize(bool keepConfig) {}
+	static void KillAll() {}
+	static void GameLoop() {}
+	static bool HasAI(const struct ContentInfo *ci, bool md5sum) { return false; }
+	static void Rescan() {}
+	static char *GetConsoleList(char *p, const char *last) { return p; }
+	static void nop() { }
+};
+
+#endif /* ENABLE_AI */
 #endif /* AI_HPP */
diff --git a/src/ai/ai_config.hpp b/src/ai/ai_config.hpp
--- a/src/ai/ai_config.hpp
+++ b/src/ai/ai_config.hpp
@@ -11,6 +11,7 @@
 
 #ifndef AI_CONFIG_HPP
 #define AI_CONFIG_HPP
+#ifdef ENABLE_AI
 
 #include <map>
 #include "ai_info.hpp"
@@ -130,4 +131,5 @@
 	bool is_random_ai;
 };
 
+#endif /* ENABLE_AI */
 #endif /* AI_CONFIG_HPP */
diff --git a/src/ai/ai_gui.hpp b/src/ai/ai_gui.hpp
--- a/src/ai/ai_gui.hpp
+++ b/src/ai/ai_gui.hpp
@@ -14,7 +14,17 @@
 
 #include "../company_type.h"
 
+#ifdef ENABLE_AI
 void ShowAIDebugWindow(CompanyID show_company = INVALID_COMPANY);
 void ShowAIConfigWindow();
+#else
+#include "table/strings.h"
+
+static inline void ShowAIConfigWindow()
+{
+	ShowErrorMessage(STR_ERROR_NO_AI, STR_ERROR_NO_AI_SUB, 0, 0);
+}
+static inline void ShowAIDebugWindow(CompanyID show_company = INVALID_COMPANY) {ShowAIConfigWindow();}
+#endif /* ENABLE_AI */
 
 #endif /* AI_GUI_HPP */
diff --git a/src/ai/ai_info.hpp b/src/ai/ai_info.hpp
--- a/src/ai/ai_info.hpp
+++ b/src/ai/ai_info.hpp
@@ -12,6 +12,8 @@
 #ifndef AI_INFO
 #define AI_INFO
 
+#ifdef ENABLE_AI
+
 #include <list>
 #include "../core/smallmap_type.hpp"
 #include "../script/script_info.hpp"
@@ -141,4 +143,5 @@
 	const char *category;
 };
 
+#endif /* ENABLE_AI */
 #endif /* AI_INFO */
diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -1269,17 +1269,14 @@
 	v->Next()->cargo.Truncate(0);
 	const Station *st = GetTargetAirportIfValid(v);
 	StringID newsitem;
-	AIEventVehicleCrashed::CrashReason crash_reason;
 	if (st == NULL) {
 		newsitem = STR_NEWS_PLANE_CRASH_OUT_OF_FUEL;
-		crash_reason = AIEventVehicleCrashed::CRASH_AIRCRAFT_NO_AIRPORT;
 	} else {
 		SetDParam(1, st->index);
 		newsitem = STR_NEWS_AIRCRAFT_CRASH;
-		crash_reason = AIEventVehicleCrashed::CRASH_PLANE_LANDING;
 	}
 
-	AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, crash_reason));
+	AI::NewEvent(v->owner, new AIEventVehicleCrashed(v->index, v->tile, st == NULL ? AIEventVehicleCrashed::CRASH_AIRCRAFT_NO_AIRPORT : AIEventVehicleCrashed::CRASH_PLANE_LANDING));
 
 	AddVehicleNewsItem(newsitem,
 		NS_ACCIDENT,
diff --git a/src/company_cmd.cpp b/src/company_cmd.cpp
--- a/src/company_cmd.cpp
+++ b/src/company_cmd.cpp
@@ -507,6 +507,7 @@
 	_next_competitor_start = 0;
 }
 
+#ifdef ENABLE_AI
 static void MaybeStartNewCompany()
 {
 #ifdef ENABLE_NETWORK
@@ -527,6 +528,7 @@
 		DoCommandP(0, 1, INVALID_COMPANY, CMD_COMPANY_CTRL);
 	}
 }
+#endif /* ENABLE_AI */
 
 void InitializeCompanies()
 {
@@ -608,6 +610,7 @@
 		if (c->bankrupt_asked != 0) HandleBankruptcyTakeover(c);
 	}
 
+#ifdef ENABLE_AI
 	if (_next_competitor_start == 0) {
 		_next_competitor_start = AI::GetStartNextTime() * DAY_TICKS;
 	}
@@ -615,6 +618,7 @@
 	if (AI::CanStartNew() && _game_mode != GM_MENU && --_next_competitor_start == 0) {
 		MaybeStartNewCompany();
 	}
+#endif /* ENABLE_AI */
 
 	_cur_company_tick_index = (_cur_company_tick_index + 1) % MAX_COMPANIES;
 }
diff --git a/src/console_cmds.cpp b/src/console_cmds.cpp
--- a/src/console_cmds.cpp
+++ b/src/console_cmds.cpp
@@ -991,6 +991,7 @@
 	return true;
 }
 
+#ifdef ENABLE_AI
 DEF_CONSOLE_CMD(ConListAI)
 {
 	char buf[4096];
@@ -1157,6 +1158,7 @@
 
 	return true;
 }
+#endif /* ENABLE_AI */
 
 DEF_CONSOLE_CMD(ConGetSeed)
 {
@@ -1793,7 +1795,6 @@
 	IConsoleCmdRegister("help",         ConHelp);
 	IConsoleCmdRegister("info_cmd",     ConInfoCmd);
 	IConsoleCmdRegister("info_var",     ConInfoVar);
-	IConsoleCmdRegister("list_ai",      ConListAI);
 	IConsoleCmdRegister("list_cmds",    ConListCommands);
 	IConsoleCmdRegister("list_vars",    ConListVariables);
 	IConsoleCmdRegister("list_aliases", ConListAliases);
@@ -1802,8 +1803,6 @@
 	IConsoleCmdRegister("getseed",      ConGetSeed);
 	IConsoleCmdRegister("getdate",      ConGetDate);
 	IConsoleCmdRegister("quit",         ConExit);
-	IConsoleCmdRegister("reload_ai",    ConReloadAI);
-	IConsoleCmdRegister("rescan_ai",    ConRescanAI);
 	IConsoleCmdRegister("resetengines", ConResetEngines);
 	IConsoleCmdRegister("return",       ConReturn);
 	IConsoleCmdRegister("screenshot",   ConScreenShot);
@@ -1814,8 +1813,6 @@
 	IConsoleCmdRegister("rm",           ConRemove);
 	IConsoleCmdRegister("save",         ConSave);
 	IConsoleCmdRegister("saveconfig",   ConSaveConfig);
-	IConsoleCmdRegister("start_ai",     ConStartAI);
-	IConsoleCmdRegister("stop_ai",      ConStopAI);
 	IConsoleCmdRegister("ls",           ConListFiles);
 	IConsoleCmdRegister("cd",           ConChangeDirectory);
 	IConsoleCmdRegister("pwd",          ConPrintWorkingDirectory);
@@ -1835,7 +1832,13 @@
 	IConsoleAliasRegister("set_newgame",  "setting_newgame %+");
 	IConsoleAliasRegister("list_patches", "list_settings %+");
 
-
+#ifdef ENABLE_AI
+	IConsoleCmdRegister("list_ai",      ConListAI);
+	IConsoleCmdRegister("reload_ai",    ConReloadAI);
+	IConsoleCmdRegister("rescan_ai",    ConRescanAI);
+	IConsoleCmdRegister("start_ai",     ConStartAI);
+	IConsoleCmdRegister("stop_ai",      ConStopAI);
+#endif /* ENABLE_AI */
 
 	IConsoleVarRegister("developer", &_stdlib_developer, ICONSOLE_VAR_BYTE, "Redirect debugging output from the console/command line to the ingame console (value 2). Default value: 1");
 
diff --git a/src/crashlog.cpp b/src/crashlog.cpp
--- a/src/crashlog.cpp
+++ b/src/crashlog.cpp
@@ -134,7 +134,9 @@
 		if (c->ai_info == NULL) {
 			buffer += seprintf(buffer, last, " %2i: Human\n", (int)c->index);
 		} else {
+#ifdef ENABLE_AI
 			buffer += seprintf(buffer, last, " %2i: %s (v%d)\n", (int)c->index, c->ai_info->GetName(), c->ai_info->GetVersion());
+#endif /* ENABLE_AI */
 		}
 	}
 	buffer += seprintf(buffer, last, "\n");
diff --git a/src/lang/english.txt b/src/lang/english.txt
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -3218,6 +3218,9 @@
 STR_AI_DEBUG_RELOAD                                             :{BLACK}Reload AI
 STR_AI_DEBUG_RELOAD_TOOLTIP                                     :{BLACK}Kill the AI, reload the script, and restart the AI
 
+STR_ERROR_NO_AI                                                 :{WHITE}OpenTTD is build without AI support...
+STR_ERROR_NO_AI_SUB                                             :{WHITE}... no AIs are available!
+
 STR_ERROR_AI_NO_AI_FOUND                                        :No suitable AI found to load.{}This AI is a dummy AI and won't do anything.{}You can download several AIs via the 'Online Content' system.
 STR_ERROR_AI_PLEASE_REPORT_CRASH                                :{WHITE}One of the running AIs crashed. Please report this to the AI author with a screenshot of the AI Debug Window.
 STR_ERROR_AI_DEBUG_SERVER_ONLY                                  :{YELLOW}AI Debug window is only available for the server
diff --git a/src/network/network_command.cpp b/src/network/network_command.cpp
--- a/src/network/network_command.cpp
+++ b/src/network/network_command.cpp
@@ -38,7 +38,11 @@
 	/* 0x0F */ CcPlaySound1E,
 	/* 0x10 */ CcStation,
 	/* 0x11 */ CcTerraform,
+#ifdef ENABLE_AI
 	/* 0x12 */ CcAI,
+#else
+	/* 0x12 */ NULL,
+#endif /* ENABLE_AI */
 	/* 0x13 */ CcCloneVehicle,
 	/* 0x14 */ CcGiveMoney,
 	/* 0x15 */ CcCreateGroup,
diff --git a/src/network/network_content.cpp b/src/network/network_content.cpp
--- a/src/network/network_content.cpp
+++ b/src/network/network_content.cpp
@@ -167,9 +167,11 @@
 		this->RequestContentList(CONTENT_TYPE_BASE_SOUNDS);
 		this->RequestContentList(CONTENT_TYPE_SCENARIO);
 		this->RequestContentList(CONTENT_TYPE_HEIGHTMAP);
+#ifdef ENABLE_AI
 		this->RequestContentList(CONTENT_TYPE_AI);
+		this->RequestContentList(CONTENT_TYPE_AI_LIBRARY);
+#endif /* ENABLE_AI */
 		this->RequestContentList(CONTENT_TYPE_NEWGRF);
-		this->RequestContentList(CONTENT_TYPE_AI_LIBRARY);
 		return;
 	}
 
diff --git a/src/openttd.cpp b/src/openttd.cpp
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -385,20 +385,24 @@
 
 void MakeNewgameSettingsLive()
 {
+#ifdef ENABLE_AI
 	for (CompanyID c = COMPANY_FIRST; c < MAX_COMPANIES; c++) {
 		if (_settings_game.ai_config[c] != NULL) {
 			delete _settings_game.ai_config[c];
 		}
 	}
+#endif /* ENABLE_AI */
 
 	_settings_game = _settings_newgame;
 
+#ifdef ENABLE_AI
 	for (CompanyID c = COMPANY_FIRST; c < MAX_COMPANIES; c++) {
 		_settings_game.ai_config[c] = NULL;
 		if (_settings_newgame.ai_config[c] != NULL) {
 			_settings_game.ai_config[c] = new AIConfig(_settings_newgame.ai_config[c]);
 		}
 	}
+#endif /* ENABLE_AI */
 }
 
 byte _savegame_sort_order;
diff --git a/src/saveload/ai_sl.cpp b/src/saveload/ai_sl.cpp
--- a/src/saveload/ai_sl.cpp
+++ b/src/saveload/ai_sl.cpp
@@ -14,10 +14,6 @@
 #include "../debug.h"
 #include "saveload.h"
 #include "../string_func.h"
-#include "../ai/ai.hpp"
-#include "../ai/ai_config.hpp"
-#include "../network/network.h"
-#include "../ai/ai_instance.hpp"
 
 static char _ai_saveload_name[64];
 static int  _ai_saveload_version;
@@ -32,6 +28,12 @@
 	     SLE_END()
 };
 
+#ifdef ENABLE_AI
+#include "../ai/ai.hpp"
+#include "../ai/ai_config.hpp"
+#include "../network/network.h"
+#include "../ai/ai_instance.hpp"
+
 static void SaveReal_AIPL(int *index_ptr)
 {
 	CompanyID index = (CompanyID)*index_ptr;
@@ -121,3 +123,80 @@
 extern const ChunkHandler _ai_chunk_handlers[] = {
 	{ 'AIPL', Save_AIPL, Load_AIPL, NULL, CH_ARRAY | CH_LAST},
 };
+#else
+
+/** The type of the data that follows in the savegame. */
+enum SQSaveLoadType {
+	SQSL_INT             = 0x00, ///< The following data is an integer.
+	SQSL_STRING          = 0x01, ///< The following data is an string.
+	SQSL_ARRAY           = 0x02, ///< The following data is an array.
+	SQSL_TABLE           = 0x03, ///< The following data is an table.
+	SQSL_BOOL            = 0x04, ///< The following data is a boolean.
+	SQSL_NULL            = 0x05, ///< A null variable.
+	SQSL_ARRAY_TABLE_END = 0xFF, ///< Marks the end of an array or table, no data follows.
+};
+
+static byte _ai_sl_byte;
+
+static const SaveLoad _ai_byte[] = {
+	SLEG_VAR(_ai_sl_byte, SLE_UINT8),
+	SLE_END()
+};
+
+static bool LoadObjects()
+{
+	SlObject(NULL, _ai_byte);
+	switch (_ai_sl_byte) {
+		case SQSL_INT: {
+			int value;
+			SlArray(&value, 1, SLE_INT32);
+			return true;
+		}
+
+		case SQSL_STRING: {
+			SlObject(NULL, _ai_byte);
+			static char buf[256];
+			SlArray(buf, _ai_sl_byte, SLE_CHAR);
+			return true;
+		}
+
+		case SQSL_ARRAY:
+			while (LoadObjects()) { }
+			return true;
+
+		case SQSL_TABLE:
+			while (LoadObjects()) { LoadObjects(); }
+			return true;
+
+		case SQSL_BOOL:
+			SlObject(NULL, _ai_byte);
+			return true;
+
+		case SQSL_NULL:
+			return true;
+
+		case SQSL_ARRAY_TABLE_END:
+			return false;
+
+		default: NOT_REACHED();
+	}
+}
+
+static void Load_AIPL()
+{
+	CompanyID index;
+	while ((index = (CompanyID)SlIterateArray()) != (CompanyID)-1) {
+		SlObject(NULL, _ai_company);
+
+		if (!Company::IsValidAiID(index)) continue;
+		SlObject(NULL, _ai_byte);
+		/* Check if there was anything saved at all. */
+		if (_ai_sl_byte == 0) continue;
+		LoadObjects();
+	}
+}
+
+extern const ChunkHandler _ai_chunk_handlers[] = {
+	{ 'AIPL', NULL, Load_AIPL, NULL, CH_ARRAY | CH_LAST},
+};
+#endif /* ENABLE_AI */
diff --git a/src/settings.cpp b/src/settings.cpp
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -866,7 +866,10 @@
 	}
 
 	if (((_game_mode == GM_MENU) ? _settings_newgame.difficulty : _settings_game.difficulty).max_no_competitors != 0 &&
-			AI::GetInfoList()->size() == 0 && (!_networking || _network_server)) {
+#ifdef ENABLE_AI
+			AI::GetInfoList()->size() == 0 &&
+#endif /* ENABLE_AI */
+			(!_networking || _network_server)) {
 		ShowErrorMessage(STR_WARNING_NO_SUITABLE_AI, INVALID_STRING_ID, 0, 0, true);
 	}
 
@@ -1145,6 +1148,7 @@
 
 static void AILoadConfig(IniFile *ini, const char *grpname)
 {
+#ifdef ENABLE_AI
 	IniGroup *group = ini->GetGroup(grpname);
 	IniItem *item;
 
@@ -1169,6 +1173,7 @@
 		}
 		if (item->value != NULL) config->StringToSettings(item->value);
 	}
+#endif /* ENABLE_AI */
 }
 
 /* Load a GRF configuration from the given group name */
@@ -1254,6 +1259,7 @@
 
 static void AISaveConfig(IniFile *ini, const char *grpname)
 {
+#ifdef ENABLE_AI
 	IniGroup *group = ini->GetGroup(grpname);
 
 	if (group == NULL) return;
@@ -1274,6 +1280,7 @@
 		IniItem *item = new IniItem(group, name, strlen(name));
 		item->SetValue(value);
 	}
+#endif /* ENABLE_AI */
 }
 
 /**
diff --git a/src/settings_gui.cpp b/src/settings_gui.cpp
--- a/src/settings_gui.cpp
+++ b/src/settings_gui.cpp
@@ -655,8 +655,11 @@
 			this->LowerWidget(GDW_LVL_CUSTOM);
 			this->InvalidateData();
 
-			if (widget / 3 == 0 && this->opt_mod_temp.difficulty.max_no_competitors != 0 &&
-					AI::GetInfoList()->size() == 0) {
+			if (widget / 3 == 0 &&
+#ifdef ENABLE_AI
+					AI::GetInfoList()->size() == 0 &&
+#endif /* ENABLE_AI */
+					this->opt_mod_temp.difficulty.max_no_competitors != 0) {
 				ShowErrorMessage(STR_WARNING_NO_SUITABLE_AI, INVALID_STRING_ID, 0, 0, true);
 			}
 			return;