- serialize the temporary music volume that can be set through ACS.

src/p_saveg.cpp

@@ -546,19 +546,22 @@ void P_SerializeSounds(FSerializer &arc)
 	DSeqNode::SerializeSequences (arc);
 	const char *name = NULL;
 	uint8_t order;
+	float musvol = level.MusicVolume;
 
 	if (arc.isWriting())
 	{
 		order = S_GetMusic(&name);
 	}
 	arc.StringPtr("musicname", name)
-		("musicorder", order);
+		("musicorder", order)
+		("musicvolume", musvol);
 
 	if (arc.isReading())
 	{
 		if (!S_ChangeMusic(name, order))
 			if (level.cdtrack == 0 || !S_ChangeCDMusic(level.cdtrack, level.cdid))
 				S_ChangeMusic(level.Music, level.musicorder);
+		level.SetMusicVolume(musvol);
 	}
 }