Function ReadLanguagePack

src/strings.cpp:2048–2144

* Read a particular language. * @param lang The metadata about the language. * @return Whether the loading went okay or not. */

 * @return Whether the loading went okay or not.
 */
bool ReadLanguagePack(const LanguageMetadata *lang)
{
	/* Current language pack */
	size_t total_len = 0;
	std::unique_ptr<LanguagePack, LanguagePackDeleter> lang_pack(reinterpret_cast<LanguagePack *>(ReadFileToMem(FS2OTTD(lang->file.native()), total_len, 1U << 20).release()));
	if (!lang_pack) return false;

	/* End of read data (+ terminating zero added in ReadFileToMem()) */
	const char *end = (char *)lang_pack.get() + total_len + 1;

	/* We need at least one byte of lang_pack->data */
	if (end <= lang_pack->data || !lang_pack->IsValid()) {
		return false;
	}

	std::array<uint, TEXT_TAB_END> tab_start, tab_num;

	uint count = 0;
	for (uint i = 0; i < TEXT_TAB_END; i++) {
		uint16_t num = FROM_LE16(lang_pack->offsets[i]);
		if (num > TAB_SIZE) return false;

		tab_start[i] = count;
		tab_num[i] = num;
		count += num;
	}

	/* Allocate offsets */
	std::vector<std::string_view> strings;

	/* Fill offsets */
	char *s = lang_pack->data;
	for (uint i = 0; i < count; i++) {
		size_t len = static_cast<uint8_t>(*s++);
		if (s + len >= end) return false;

		if (len >= 0xC0) {
			len = ((len & 0x3F) << 8) + static_cast<uint8_t>(*s++);
			if (s + len >= end) return false;
		}
		strings.emplace_back(s, len);
		s += len;
	}
	assert(strings.size() == count);

	_langpack.langpack = std::move(lang_pack);
	_langpack.strings = std::move(strings);
	_langpack.langtab_num = tab_num;
	_langpack.langtab_start = tab_start;

	_current_language = lang;
	_current_text_dir = (TextDirection)_current_language->text_dir;
	_config_language_file = FS2OTTD(_current_language->file.filename().native());
	SetCurrentGrfLangID(_current_language->newgrflangid);
	_langpack.list_separator = GetString(STR_LIST_SEPARATOR);
	_langpack.ellipsis = GetString(STR_TRUNCATION_ELLIPSIS);

#ifdef _WIN32