fs/Path: add method ToUTF8Throw()

src/PlaylistFile.cxx

@@ -143,11 +143,13 @@ LoadPlaylistFileInfo(PlaylistInfo &info,
 		return false;
 
 	const auto name = AllocatedPath::FromFS(name_fs_str, name_fs_end);
-	std::string name_utf8 = name.ToUTF8();
-	if (name_utf8.empty())
-		return false;
 
-	info.name = std::move(name_utf8);
+	try {
+		info.name = name.ToUTF8Throw();
+	} catch (...) {
+		return false;
+	}
+
 	info.mtime = fi.GetModificationTime();
 	return true;
 }

src/PlaylistSave.cxx

@@ -41,7 +41,10 @@ playlist_print_path(BufferedOutputStream &os, const Path path)
 	/* on Windows, playlists always contain UTF-8, because its
 	   "narrow" charset (i.e. CP_ACP) is incapable of storing all
 	   Unicode paths */
-	os.Format("%s\n", path.ToUTF8().c_str());
+	try {
+		os.Format("%s\n", path.ToUTF8Throw().c_str());
+	} catch (...) {
+	}
 #else
 	os.Format("%s\n", path.c_str());
 #endif

src/fs/AllocatedPath.hxx

@@ -253,6 +253,10 @@ public:
 		return ((Path)*this).ToUTF8();
 	}
 
+	std::string ToUTF8Throw() const {
+		return ((Path)*this).ToUTF8Throw();
+	}
+
 	/**
 	 * Gets directory name of this path.
 	 * Returns a "nulled" instance on error.

src/fs/Path.cxx

@@ -25,12 +25,18 @@ std::string
 Path::ToUTF8() const noexcept
 {
 	try {
-		return ::PathToUTF8(c_str());
+		return ToUTF8Throw();
 	} catch (...) {
 		return std::string();
 	}
 }
 
+std::string
+Path::ToUTF8Throw() const
+{
+	return ::PathToUTF8(c_str());
+}
+
 Path::const_pointer_type
 Path::GetSuffix() const noexcept
 {

src/fs/Path.hxx

@@ -134,6 +134,11 @@ public:
 	gcc_pure
 	std::string ToUTF8() const noexcept;
 
+	/**
+	 * Like ToUTF8(), but throws on error.
+	 */
+	std::string ToUTF8Throw() const;
+
 	/**
 	 * Determine the "base" file name.
 	 * The return value points inside this object.

src/input/plugins/FileInputPlugin.cxx

@@ -72,7 +72,7 @@ OpenFileInputStream(Path path, Mutex &mutex)
 #endif
 #endif
 
-	return std::make_unique<FileInputStream>(path.ToUTF8().c_str(),
+	return std::make_unique<FileInputStream>(path.ToUTF8Throw().c_str(),
 						 std::move(reader), info.GetSize(),
 						 mutex);
 }

src/playlist/PlaylistStream.cxx

@@ -40,7 +40,7 @@ try {
 	if (suffix == nullptr)
 		return nullptr;
 
-	const auto suffix_utf8 = Path::FromFS(suffix).ToUTF8();
+	const auto suffix_utf8 = Path::FromFS(suffix).ToUTF8Throw();
 	if (!playlist_suffix_supported(suffix_utf8.c_str()))
 		return nullptr;
 
@@ -57,10 +57,8 @@ playlist_open_path(Path path, Mutex &mutex)
 try {
 	assert(!path.IsNull());
 
-	const std::string uri_utf8 = path.ToUTF8();
-	auto playlist = !uri_utf8.empty()
-		? playlist_list_open_uri(uri_utf8.c_str(), mutex)
-		: nullptr;
+	const std::string uri_utf8 = path.ToUTF8Throw();
+	auto playlist = playlist_list_open_uri(uri_utf8.c_str(), mutex);
 	if (playlist == nullptr)
 		playlist = playlist_open_path_suffix(path, mutex);
 

src/storage/plugins/LocalStorage.cxx

@@ -51,7 +51,7 @@ class LocalStorage final : public Storage {
 
 public:
 	explicit LocalStorage(Path _base_fs)
-		:base_fs(_base_fs), base_utf8(base_fs.ToUTF8()) {
+		:base_fs(_base_fs), base_utf8(base_fs.ToUTF8Throw()) {
 		assert(!base_fs.IsNull());
 		assert(!base_utf8.empty());
 	}
@@ -162,11 +162,11 @@ LocalDirectoryReader::Read() noexcept
 		if (SkipNameFS(name_fs.c_str()))
 			continue;
 
-		name_utf8 = name_fs.ToUTF8();
-		if (name_utf8.empty())
-			continue;
-
-		return name_utf8.c_str();
+		try {
+			name_utf8 = name_fs.ToUTF8Throw();
+			return name_utf8.c_str();
+		} catch (...) {
+		}
 	}
 
 	return nullptr;

src/storage/plugins/NfsStorage.cxx

@@ -378,14 +378,13 @@ NfsListDirectoryOperation::CollectEntries(struct nfsdir *dir)
 		if (SkipNameFS(name_fs.c_str()))
 			continue;
 
-		std::string name_utf8 = name_fs.ToUTF8();
-		if (name_utf8.empty())
+		try {
+			entries.emplace_front(name_fs.ToUTF8Throw());
+			Copy(entries.front().info, *ent);
+		} catch (...) {
 			/* ignore files whose name cannot be converted
 			   to UTF-8 */
-			continue;
-
-		entries.emplace_front(std::move(name_utf8));
-		Copy(entries.front().info, *ent);
+		}
 	}
 }
 

test/ContainerScan.cxx

@@ -48,12 +48,9 @@ FindContainerDecoderPlugin(const char *suffix)
 static const DecoderPlugin *
 FindContainerDecoderPlugin(Path path)
 {
-	const auto utf8 = path.ToUTF8();
-	if (utf8.empty())
-		return nullptr;
-
 	UriSuffixBuffer suffix_buffer;
-	const char *const suffix = uri_get_suffix(utf8.c_str(), suffix_buffer);
+	const char *const suffix = uri_get_suffix(path.ToUTF8Throw().c_str(),
+						  suffix_buffer);
 	if (suffix == nullptr)
 		return nullptr;