Codechange: use std::string_view for locales

src/os/macosx/macos.mm

@@ -151,7 +151,7 @@ void OSOpenBrowser(const std::string &url)
 /**
  * Determine and return the current user's locale.
  */
-const char *GetCurrentLocale(const char *)
+std::optional<std::string_view> GetCurrentLocale(const char *)
 {
 	static char retbuf[32] = { '\0' };
 	NSUserDefaults *defs = [ NSUserDefaults standardUserDefaults ];

src/os/unix/unix.cpp

@@ -89,7 +89,7 @@ bool FiosIsHiddenFile(const std::filesystem::path &path)
 #include "../../debug.h"
 #include "../../string_func.h"
 
-const char *GetCurrentLocale(const char *param);
+std::optional<std::string_view> GetCurrentLocale(const char *param);
 
 #define INTERNALCODE "UTF-8"
 
@@ -98,16 +98,17 @@ const char *GetCurrentLocale(const char *param);
  * variables. MacOSX is hardcoded, other OS's are dynamic. If no suitable
  * locale can be found, don't do any conversion ""
  */
-static const char *GetLocalCode()
+static std::string_view GetLocalCode()
 {
 #if defined(__APPLE__)
 	return "UTF-8-MAC";
 #else
 	/* Strip locale (eg en_US.UTF-8) to only have UTF-8 */
-	const char *locale = GetCurrentLocale("LC_CTYPE");
+	auto locale = GetCurrentLocale("LC_CTYPE");
-	if (locale != nullptr) locale = strchr(locale, '.');
+	if (!locale.has_value()) return "";
-
+	auto pos = locale->find('.');
-	return (locale == nullptr) ? "" : locale + 1;
+	if (pos == std::string_view::npos) return "";
+	return locale->substr(pos + 1);
 #endif
 }
 
@@ -151,8 +152,8 @@ std::string OTTD2FS(std::string_view name)
 {
 	static iconv_t convd = (iconv_t)(-1);
 	if (convd == (iconv_t)(-1)) {
-		const char *env = GetLocalCode();
+		std::string env{GetLocalCode()};
-		convd = iconv_open(env, INTERNALCODE);
+		convd = iconv_open(env.c_str(), INTERNALCODE);
 		if (convd == (iconv_t)(-1)) {
 			Debug(misc, 0, "[iconv] conversion from codeset '{}' to '{}' unsupported", INTERNALCODE, env);
 			return std::string{name};
@@ -171,8 +172,8 @@ std::string FS2OTTD(std::string_view name)
 {
 	static iconv_t convd = (iconv_t)(-1);
 	if (convd == (iconv_t)(-1)) {
-		const char *env = GetLocalCode();
+		std::string env{GetLocalCode()};
-		convd = iconv_open(INTERNALCODE, env);
+		convd = iconv_open(INTERNALCODE, env.c_str());
 		if (convd == (iconv_t)(-1)) {
 			Debug(misc, 0, "[iconv] conversion from codeset '{}' to '{}' unsupported", env, INTERNALCODE);
 			return std::string{name};

src/os/windows/win32.cpp

@@ -395,7 +395,7 @@ wchar_t *convert_to_fs(std::string_view src, std::span<wchar_t> dst_buf)
 }
 
 /** Determine the current user's locale. */
-const char *GetCurrentLocale(const char *)
+std::optional<std::string_view> GetCurrentLocale(const char *)
 {
 	const LANGID userUiLang = GetUserDefaultUILanguage();
 	const LCID userUiLocale = MAKELCID(userUiLang, SORT_DEFAULT);

src/strings.cpp

@@ -2083,25 +2083,23 @@ bool ReadLanguagePack(const LanguageMetadata *lang)
  *        set. Pass nullptr if you don't want additional checks.
  * @return return string containing current charset, or nullptr if not-determinable
  */
-const char *GetCurrentLocale(const char *param)
+std::optional<std::string_view> GetCurrentLocale(const char *param)
 {
-	const char *env;
+	auto env = GetEnv("LANGUAGE");
+	if (env.has_value()) return env;
 
-	env = std::getenv("LANGUAGE");
+	env = GetEnv("LC_ALL");
-	if (env != nullptr) return env;
+	if (env.has_value()) return env;
-
-	env = std::getenv("LC_ALL");
-	if (env != nullptr) return env;
 
 	if (param != nullptr) {
-		env = std::getenv(param);
+		env = GetEnv(param);
-		if (env != nullptr) return env;
+		if (env.has_value()) return env;
 	}
 
-	return std::getenv("LANG");
+	return GetEnv("LANG");
 }
 #else
-const char *GetCurrentLocale(const char *param);
+std::optional<std::string_view> GetCurrentLocale(const char *param);
 #endif /* !(defined(_WIN32) || defined(__APPLE__)) */
 
 /**
@@ -2182,8 +2180,8 @@ void InitializeLanguagePacks()
 	if (_languages.empty()) UserError("No available language packs (invalid versions?)");
 
 	/* Acquire the locale of the current system */
-	const char *lang = GetCurrentLocale("LC_MESSAGES");
+	auto lang = GetCurrentLocale("LC_MESSAGES");
-	if (lang == nullptr) lang = "en_GB";
+	if (!lang.has_value()) lang = "en_GB";
 
 	const LanguageMetadata *chosen_language   = nullptr; ///< Matching the language in the configuration file or the current locale
 	const LanguageMetadata *language_fallback = nullptr; ///< Using pt_PT for pt_BR locale when pt_BR is not available
@@ -2199,13 +2197,14 @@ void InitializeLanguagePacks()
 			break;
 		}
 
-		if (strcmp (lng.isocode, "en_GB") == 0) en_GB_fallback    = &lng;
+		std::string_view iso_code = lng.isocode;
+		if (iso_code == "en_GB") en_GB_fallback = &lng;
 
 		/* Only auto-pick finished translations */
 		if (!lng.IsReasonablyFinished()) continue;
 
-		if (strncmp(lng.isocode, lang, 5) == 0) chosen_language   = &lng;
+		if (iso_code.starts_with(lang->substr(0, 5))) chosen_language = &lng;
-		if (strncmp(lng.isocode, lang, 2) == 0) language_fallback = &lng;
+		if (iso_code.starts_with(lang->substr(0, 2))) language_fallback = &lng;
 	}
 
 	/* We haven't found the language in the config nor the one in the locale.