PlaylistFile: convert system_error::ENOENT to PlaylistResult::NO_SUCH_LIST

src/PlaylistError.hxx

@@ -55,6 +55,11 @@ public:
 				     "No such song");
 	}
 
+	static PlaylistError NoSuchList() {
+		return PlaylistError(PlaylistResult::NO_SUCH_LIST,
+				     "No such playlist");
+	}
+
 	static PlaylistError BadRange() {
 		return PlaylistError(PlaylistResult::BAD_RANGE,
 				     "Bad song index");

src/PlaylistFile.cxx

@@ -247,7 +247,7 @@ SavePlaylistFile(const PlaylistFileContents &contents, const char *utf8path,
 
 PlaylistFileContents
 LoadPlaylistFile(const char *utf8path, Error &error)
-{
+try {
 	PlaylistFileContents contents;
 
 	const auto path_fs = spl_map_to_fs(utf8path, error);
@@ -301,6 +301,10 @@ LoadPlaylistFile(const char *utf8path, Error &error)
 	}
 
 	return contents;
+} catch (const std::system_error &e) {
+	if (IsFileNotFound(e))
+		throw PlaylistError::NoSuchList();
+	throw;
 }
 
 bool
@@ -393,7 +397,7 @@ spl_remove_index(const char *utf8path, unsigned pos, Error &error)
 
 bool
 spl_append_song(const char *utf8path, const DetachedSong &song, Error &error)
-{
+try {
 	const auto path_fs = spl_map_to_fs(utf8path, error);
 	if (path_fs.IsNull())
 		return false;
@@ -415,6 +419,10 @@ spl_append_song(const char *utf8path, const DetachedSong &song, Error &error)
 
 	idle_add(IDLE_STORED_PLAYLIST);
 	return true;
+} catch (const std::system_error &e) {
+	if (IsFileNotFound(e))
+		throw PlaylistError::NoSuchList();
+	throw;
 }
 
 bool