4 files changed, 123 insertions, 12 deletions
diff --git a/src/script/script_info_dummy.cpp b/src/script/script_info_dummy.cpp
new file mode 100644
index 000000000..4620ce8f7
--- /dev/null
+++ b/src/script/script_info_dummy.cpp
@@ -0,0 +1,111 @@
+/* $Id$ */
+
+/*
+ * 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 script_info_dummy.cpp Implementation of a dummy Script. */
+
+#include <squirrel.h>
+#include "../stdafx.h"
+
+#include "../string_func.h"
+#include "../strings_func.h"
+#include "table/strings.h"
+
+/* The reason this exists in C++, is that a user can trash his ai/ or game/ dir,
+ *  leaving no Scripts available. The complexity to solve this is insane, and
+ *  therefor the alternative is used, and make sure there is always a Script
+ *  available, no matter what the situation is. By defining it in C++, there
+ *  is simply no way a user can delete it, and therefor safe to use. It has
+ *  to be noted that this Script is complete invisible for the user, and impossible
+ *  to select manual. It is a fail-over in case no Scripts are available.
+ */
+
+/** Run the dummy info.nut. */
+void Script_CreateDummyInfo(HSQUIRRELVM vm, const char *type, const char *dir)
+{
+	char dummy_script[4096];
+	char *dp = dummy_script;
+	dp += seprintf(dp, lastof(dummy_script), "class Dummy%s extends %sInfo {\n", type, type);
+	dp += seprintf(dp, lastof(dummy_script), "function GetAuthor()      { return \"OpenTTD Developers Team\"; }\n");
+	dp += seprintf(dp, lastof(dummy_script), "function GetName()        { return \"Dummy%s\"; }\n", type);
+	dp += seprintf(dp, lastof(dummy_script), "function GetShortName()   { return \"DUMM\"; }\n");
+	dp += seprintf(dp, lastof(dummy_script), "function GetDescription() { return \"A Dummy %s that is loaded when your %s/ dir is empty\"; }\n", type, dir);
+	dp += seprintf(dp, lastof(dummy_script), "function GetVersion()     { return 1; }\n");
+	dp += seprintf(dp, lastof(dummy_script), "function GetDate()        { return \"2008-07-26\"; }\n");
+	dp += seprintf(dp, lastof(dummy_script), "function CreateInstance() { return \"Dummy%s\"; }\n", type);
+	dp += seprintf(dp, lastof(dummy_script), "} RegisterDummy%s(Dummy%s());\n", type, type);
+
+	const SQChar *sq_dummy_script = OTTD2SQ(dummy_script);
+
+	sq_pushroottable(vm);
+
+	/* Load and run the script */
+	if (SQ_SUCCEEDED(sq_compilebuffer(vm, sq_dummy_script, scstrlen(sq_dummy_script), _SC("dummy"), SQTrue))) {
+		sq_push(vm, -2);
+		if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue))) {
+			sq_pop(vm, 1);
+			return;
+		}
+	}
+	NOT_REACHED();
+}
+
+/** Run the dummy AI and let it generate an error message. */
+void Script_CreateDummy(HSQUIRRELVM vm, StringID string, const char *type)
+{
+	/* We want to translate the error message.
+	 * We do this in three steps:
+	 * 1) We get the error message
+	 */
+	char error_message[1024];
+	GetString(error_message, string, lastof(error_message));
+
+	/* Make escapes for all quotes and slashes. */
+	char safe_error_message[1024];
+	char *q = safe_error_message;
+	for (const char *p = error_message; *p != '\0' && q < lastof(safe_error_message) - 2; p++, q++) {
+		if (*p == '"' || *p == '\\') *q++ = '\\';
+		*q = *p;
+	}
+	*q = '\0';
+
+	/* 2) We construct the AI's code. This is done by merging a header, body and footer */
+	char dummy_script[4096];
+	char *dp = dummy_script;
+	dp += seprintf(dp, lastof(dummy_script), "class Dummy%s extends %sController {\n  function Start()\n  {\n", type, type);
+
+	/* As special trick we need to split the error message on newlines and
+	 * emit each newline as a separate error printing string. */
+	char *newline;
+	char *p = safe_error_message;
+	do {
+		newline = strchr(p, '\n');
+		if (newline != NULL) *newline = '\0';
+
+		dp += seprintf(dp, lastof(dummy_script), "    %sLog.Error(\"%s\");\n", type, p);
+		p = newline + 1;
+	} while (newline != NULL);
+
+	dp = strecpy(dp, "  }\n}\n", lastof(dummy_script));
+
+	/* 3) We translate the error message in the character format that Squirrel wants.
+	 *    We can use the fact that the wchar string printing also uses %s to print
+	 *    old style char strings, which is what was generated during the script generation. */
+	const SQChar *sq_dummy_script = OTTD2SQ(dummy_script);
+
+	/* And finally we load and run the script */
+	sq_pushroottable(vm);
+	if (SQ_SUCCEEDED(sq_compilebuffer(vm, sq_dummy_script, scstrlen(sq_dummy_script), _SC("dummy"), SQTrue))) {
+		sq_push(vm, -2);
+		if (SQ_SUCCEEDED(sq_call(vm, 1, SQFalse, SQTrue))) {
+			sq_pop(vm, 1);
+			return;
+		}
+	}
+	NOT_REACHED();
+}
diff --git a/src/script/script_instance.cpp b/src/script/script_instance.cpp
index beebe2fd7..97fdfd68f 100644
--- a/src/script/script_instance.cpp
+++ b/src/script/script_instance.cpp
@@ -78,8 +78,7 @@ void ScriptInstance::Initialize(const char *main_script, const char *instance_na
 		ScriptObject::SetAllowDoCommand(false);
 		/* Load and execute the script for this script */
 		if (strcmp(main_script, "%_dummy") == 0) {
-			extern void AI_CreateAIDummy(HSQUIRRELVM vm);
-			AI_CreateAIDummy(this->engine->GetVM());
+			this->LoadDummyScript();
 		} else if (!this->engine->LoadScript(main_script) || this->engine->IsSuspended()) {
 			if (this->engine->IsSuspended()) ScriptLog::Error("This script took too long to load script. AI is not started.");
 			this->Died();
@@ -103,6 +102,7 @@ void ScriptInstance::Initialize(const char *main_script, const char *instance_na
 
 void ScriptInstance::RegisterAPI()
 {
+	extern void squirrel_register_std(Squirrel *engine);
 	squirrel_register_std(this->engine);
 }
 
diff --git a/src/script/script_instance.hpp b/src/script/script_instance.hpp
index c5ff730c7..b84a36496 100644
--- a/src/script/script_instance.hpp
+++ b/src/script/script_instance.hpp
@@ -162,6 +162,11 @@ protected:
 	 */
 	virtual CommandCallback *GetDoCommandCallback() = 0;
 
+	/**
+	 * Load the dummy script.
+	 */
+	virtual void LoadDummyScript() = 0;
+
 private:
 	class ScriptController *controller;   ///< The script main class.
 	class ScriptStorage *storage;         ///< Some global information for each running script.
diff --git a/src/script/squirrel.hpp b/src/script/squirrel.hpp
index 6b9c3ab70..dbccd3c08 100644
--- a/src/script/squirrel.hpp
+++ b/src/script/squirrel.hpp
@@ -36,11 +36,6 @@ private:
 	static SQInteger _RunError(HSQUIRRELVM vm);
 
 	/**
-	 * Get the squirrel VM. Try to avoid using this.
-	 */
-	HSQUIRRELVM GetVM() { return this->vm; }
-
-	/**
 	 * Get the API name.
 	 */
 	const char *GetAPIName() { return this->APIName; }
@@ -67,15 +62,15 @@ protected:
 	static void ErrorPrintFunc(HSQUIRRELVM vm, const SQChar *s, ...);
 
 public:
-	friend class AIScannerInfo;
-	friend class ScriptInstance;
-	friend class ScriptController;
-	friend void squirrel_register_std(Squirrel *engine);
-
 	Squirrel(const char *APIName);
 	~Squirrel();
 
 	/**
+	 * Get the squirrel VM. Try to avoid using this.
+	 */
+	HSQUIRRELVM GetVM() { return this->vm; }
+
+	/**
 	 * Load a script.
 	 * @param script The full script-name to load.
 	 * @return False if loading failed.