Codechange: Return std::vector from GetMusicCatEntryData.

Return std::vector instead of pointer to array with manual memory management.

src/base_media_base.h

@@ -313,8 +313,8 @@ static const uint NUM_SONGS_AVAILABLE = 1 + NUM_SONG_CLASSES * NUM_SONGS_CLASS;
 static const uint NUM_SONGS_PLAYLIST  = 32;
 
 /* Functions to read DOS music CAT files, similar to but not quite the same as sound effect CAT files */
-char *GetMusicCatEntryName(const std::string &filename, size_t entrynum);
-uint8_t *GetMusicCatEntryData(const std::string &filename, size_t entrynum, size_t &entrylen);
+std::optional<std::string> GetMusicCatEntryName(const std::string &filename, size_t entrynum);
+std::optional<std::vector<uint8_t>> GetMusicCatEntryData(const std::string &filename, size_t entrynum);
 
 enum MusicTrackType {
 	MTT_STANDARDMIDI, ///< Standard MIDI file

src/music.cpp

@@ -8,6 +8,7 @@
 /** @file music.cpp The songs that OpenTTD knows. */
 
 #include "stdafx.h"
+#include "string_func.h"
 
 
 /** The type of set we're replacing */
@@ -22,55 +23,50 @@
  * Read the name of a music CAT file entry.
  * @param filename Name of CAT file to read from
  * @param entrynum Index of entry whose name to read
- * @return Pointer to string, caller is responsible for freeing memory,
- *         nullptr if entrynum does not exist.
+ * @return Name of CAT file entry if it could be read.
  */
-char *GetMusicCatEntryName(const std::string &filename, size_t entrynum)
+std::optional<std::string> GetMusicCatEntryName(const std::string &filename, size_t entrynum)
 {
-	if (!FioCheckFileExists(filename, BASESET_DIR)) return nullptr;
+	if (!FioCheckFileExists(filename, BASESET_DIR)) return std::nullopt;
 
 	RandomAccessFile file(filename, BASESET_DIR);
 	uint32_t ofs = file.ReadDword();
 	size_t entry_count = ofs / 8;
-	if (entrynum < entry_count) {
-		file.SeekTo(entrynum * 8, SEEK_SET);
-		file.SeekTo(file.ReadDword(), SEEK_SET);
-		uint8_t namelen = file.ReadByte();
-		char *name = MallocT<char>(namelen + 1);
-		file.ReadBlock(name, namelen);
-		name[namelen] = '\0';
-		return name;
-	}
-	return nullptr;
+	if (entrynum >= entry_count) return std::nullopt;
+
+	file.SeekTo(entrynum * 8, SEEK_SET);
+	file.SeekTo(file.ReadDword(), SEEK_SET);
+	uint8_t namelen = file.ReadByte();
+
+	std::string name(namelen, '\0');
+	file.ReadBlock(name.data(), namelen);
+	return StrMakeValid(name);
 }
 
 /**
  * Read the full data of a music CAT file entry.
  * @param filename Name of CAT file to read from.
  * @param entrynum Index of entry to read
- * @param[out] entrylen Receives length of data read
- * @return Pointer to buffer with data read, caller is responsible for freeind memory,
- *         nullptr if entrynum does not exist.
+ * @return Data of CAT file entry.
  */
-uint8_t *GetMusicCatEntryData(const std::string &filename, size_t entrynum, size_t &entrylen)
+std::optional<std::vector<uint8_t>> GetMusicCatEntryData(const std::string &filename, size_t entrynum)
 {
-	entrylen = 0;
-	if (!FioCheckFileExists(filename, BASESET_DIR)) return nullptr;
+	if (!FioCheckFileExists(filename, BASESET_DIR)) return std::nullopt;
 
 	RandomAccessFile file(filename, BASESET_DIR);
 	uint32_t ofs = file.ReadDword();
 	size_t entry_count = ofs / 8;
-	if (entrynum < entry_count) {
-		file.SeekTo(entrynum * 8, SEEK_SET);
-		size_t entrypos = file.ReadDword();
-		entrylen = file.ReadDword();
-		file.SeekTo(entrypos, SEEK_SET);
-		file.SkipBytes(file.ReadByte());
-		uint8_t *data = MallocT<uint8_t>(entrylen);
-		file.ReadBlock(data, entrylen);
-		return data;
-	}
-	return nullptr;
+	if (entrynum >= entry_count) return std::nullopt;
+
+	file.SeekTo(entrynum * 8, SEEK_SET);
+	size_t entrypos = file.ReadDword();
+	size_t entrylen = file.ReadDword();
+	file.SeekTo(entrypos, SEEK_SET);
+	file.SkipBytes(file.ReadByte());
+
+	std::vector<uint8_t> data(entrylen);
+	file.ReadBlock(data.data(), entrylen);
+	return data;
 }
 
 INSTANTIATE_BASE_MEDIA_METHODS(BaseMedia<MusicSet>, MusicSet)
@@ -138,13 +134,12 @@ bool MusicSet::FillSetDetails(const IniFile &ini, const std::string &path, const
 				/* Song has a CAT file index, assume it's MPS MIDI format */
 				this->songinfo[i].filetype = MTT_MPSMIDI;
 				this->songinfo[i].cat_index = atoi(item->value->c_str());
-				char *songname = GetMusicCatEntryName(filename, this->songinfo[i].cat_index);
-				if (songname == nullptr) {
+				auto songname = GetMusicCatEntryName(filename, this->songinfo[i].cat_index);
+				if (!songname.has_value()) {
 					Debug(grf, 0, "Base music set song missing from CAT file: {}/{}", filename, this->songinfo[i].cat_index);
 					continue;
 				}
-				this->songinfo[i].songname = songname;
-				free(songname);
+				this->songinfo[i].songname = *songname;
 			} else {
 				this->songinfo[i].filetype = MTT_STANDARDMIDI;
 			}

src/music/midifile.cpp

@@ -843,11 +843,9 @@ bool MidiFile::LoadSong(const MusicSongInfo &song)
 			return this->LoadFile(song.filename);
 		case MTT_MPSMIDI:
 		{
-			size_t songdatalen = 0;
-			uint8_t *songdata = GetMusicCatEntryData(song.filename, song.cat_index, songdatalen);
-			if (songdata != nullptr) {
-				bool result = this->LoadMpsData(songdata, songdatalen);
-				free(songdata);
+			auto songdata = GetMusicCatEntryData(song.filename, song.cat_index);
+			if (songdata.has_value()) {
+				bool result = this->LoadMpsData(songdata->data(), songdata->size());
 				return result;
 			} else {
 				return false;
@@ -1078,17 +1076,13 @@ std::string MidiFile::GetSMFFile(const MusicSongInfo &song)
 		return output_filename;
 	}
 
-	uint8_t *data;
-	size_t datalen;
-	data = GetMusicCatEntryData(song.filename, song.cat_index, datalen);
-	if (data == nullptr) return std::string();
+	auto songdata = GetMusicCatEntryData(song.filename, song.cat_index);
+	if (!songdata.has_value()) return std::string();
 
 	MidiFile midifile;
-	if (!midifile.LoadMpsData(data, datalen)) {
-		free(data);
+	if (!midifile.LoadMpsData(songdata->data(), songdata->size())) {
 		return std::string();
 	}
-	free(data);
 
 	if (midifile.WriteSMF(output_filename)) {
 		return output_filename;