Fix #9720: Delay start of GS/AI to after loading of savegame (#9745)

src/script/script_instance.cpp

@@ -343,17 +343,6 @@ void *ScriptInstance::GetLogPointer()
  *  - null:    No data.
  */
 
-/** 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 _script_sl_byte; ///< Used as source/target by the script saveload code to store/load a single byte.
 
 /** SaveLoad array that saves/loads exactly one byte. */
@@ -572,14 +561,14 @@ bool ScriptInstance::IsPaused()
 	return this->is_paused;
 }
 
-/* static */ bool ScriptInstance::LoadObjects(HSQUIRRELVM vm)
+/* static */ bool ScriptInstance::LoadObjects(ScriptData *data)
 {
 	SlObject(nullptr, _script_byte);
 	switch (_script_sl_byte) {
 		case SQSL_INT: {
 			int64 value;
 			SlCopy(&value, 1, IsSavegameVersionBefore(SLV_SCRIPT_INT64) ? SLE_FILE_I32 | SLE_VAR_I64 : SLE_INT64);
-			if (vm != nullptr) sq_pushinteger(vm, (SQInteger)value);
+			if (data != nullptr) data->push_back((SQInteger)value);
 			return true;
 		}
 
@@ -588,37 +577,79 @@ bool ScriptInstance::IsPaused()
 			static char buf[std::numeric_limits<decltype(_script_sl_byte)>::max()];
 			SlCopy(buf, _script_sl_byte, SLE_CHAR);
 			StrMakeValidInPlace(buf, buf + _script_sl_byte);
-			if (vm != nullptr) sq_pushstring(vm, buf, -1);
+			if (data != nullptr) data->push_back(std::string(buf));
 			return true;
 		}
 
+		case SQSL_ARRAY:
+		case SQSL_TABLE: {
+			if (data != nullptr) data->push_back((SQSaveLoadType)_script_sl_byte);
+			while (LoadObjects(data));
+			return true;
+		}
+
+		case SQSL_BOOL: {
+			SlObject(nullptr, _script_byte);
+			if (data != nullptr) data->push_back((SQBool)(_script_sl_byte != 0));
+			return true;
+		}
+
+		case SQSL_NULL: {
+			if (data != nullptr) data->push_back((SQSaveLoadType)_script_sl_byte);
+			return true;
+		}
+
+		case SQSL_ARRAY_TABLE_END: {
+			if (data != nullptr) data->push_back((SQSaveLoadType)_script_sl_byte);
+			return false;
+		}
+
+		default: SlErrorCorrupt("Invalid script data type");
+	}
+}
+
+/* static */ bool ScriptInstance::LoadObjects(HSQUIRRELVM vm, ScriptData *data)
+{
+	ScriptDataVariant value = data->front();
+	data->pop_front();
+
+	if (std::holds_alternative<SQInteger>(value)) {
+		sq_pushinteger(vm, std::get<SQInteger>(value));
+		return true;
+	}
+
+	if (std::holds_alternative<std::string>(value)) {
+		sq_pushstring(vm, std::get<std::string>(value).c_str(), -1);
+		return true;
+	}
+
+	if (std::holds_alternative<SQBool>(value)) {
+		sq_pushbool(vm, std::get<SQBool>(value));
+		return true;
+	}
+
+	switch (std::get<SQSaveLoadType>(value)) {
 		case SQSL_ARRAY: {
-			if (vm != nullptr) sq_newarray(vm, 0);
-			while (LoadObjects(vm)) {
-				if (vm != nullptr) sq_arrayappend(vm, -2);
+			sq_newarray(vm, 0);
+			while (LoadObjects(vm, data)) {
+				sq_arrayappend(vm, -2);
 				/* The value is popped from the stack by squirrel. */
 			}
 			return true;
 		}
 
 		case SQSL_TABLE: {
-			if (vm != nullptr) sq_newtable(vm);
-			while (LoadObjects(vm)) {
-				LoadObjects(vm);
-				if (vm != nullptr) sq_rawset(vm, -3);
+			sq_newtable(vm);
+			while (LoadObjects(vm, data)) {
+				LoadObjects(vm, data);
+				sq_rawset(vm, -3);
 				/* The key (-2) and value (-1) are popped from the stack by squirrel. */
 			}
 			return true;
 		}
 
-		case SQSL_BOOL: {
-			SlObject(nullptr, _script_byte);
-			if (vm != nullptr) sq_pushbool(vm, (SQBool)(_script_sl_byte != 0));
-			return true;
-		}
-
 		case SQSL_NULL: {
-			if (vm != nullptr) sq_pushnull(vm);
+			sq_pushnull(vm);
 			return true;
 		}
 
@@ -639,22 +670,35 @@ bool ScriptInstance::IsPaused()
 	LoadObjects(nullptr);
 }
 
-void ScriptInstance::Load(int version)
+/* static */ ScriptInstance::ScriptData *ScriptInstance::Load(int version)
 {
-	ScriptObject::ActiveInstance active(this);
-
-	if (this->engine == nullptr || version == -1) {
+	if (version == -1) {
 		LoadEmpty();
-		return;
+		return nullptr;
 	}
-	HSQUIRRELVM vm = this->engine->GetVM();
 
 	SlObject(nullptr, _script_byte);
 	/* Check if there was anything saved at all. */
-	if (_script_sl_byte == 0) return;
+	if (_script_sl_byte == 0) return nullptr;
 
-	sq_pushinteger(vm, version);
-	LoadObjects(vm);
+	ScriptData *data = new ScriptData();
+	data->push_back((SQInteger)version);
+	LoadObjects(data);
+	return data;
+}
+
+void ScriptInstance::LoadOnStack(ScriptData *data)
+{
+	ScriptObject::ActiveInstance active(this);
+
+	if (data == nullptr) return;
+
+	HSQUIRRELVM vm = this->engine->GetVM();
+
+	ScriptDataVariant version = data->front();
+	data->pop_front();
+	sq_pushinteger(vm, std::get<SQInteger>(version));
+	LoadObjects(vm, data);
 	this->is_save_data_on_stack = true;
 }