Current music playlist continues playing indefinitely if next playlist is empty

If the /Music/Explore folder contains no tracks, the title music from the main menu (morrowind title.mp3 from the /Music/Special folder) continues looping indefinitely during exploration. If interrupted by battle, music from the /Music/Battle folder then continues playing indefinitely even after the player is no longer in battle. Deleting the tracks in the /Music/Battle folder as well results in only the title music looping over and over again.

This is different from vanilla Morrowind, where having an empty Explore music folder results in silence during exploration.

An empty Battle folder results in the exploration music playing continuously, as expected. Both vanilla Morrowind and OpenMW do this.

According to Capo, this is because an empty playlist is not allowed to replace a currently playing playlist, as that would result in silence interrupting the exploration music if the /Music/Battle folder is empty.

Suggested altered behavior of playlist switching:

• Never switch from Explore to an empty playlist
• Always switch to Explore (even if Explore is empty)
• Only switch to Battle if it is not empty

This would mean the title music can keep playing through the menu and be allowed to finish playing after loading/starting a game, unless interrupted by battle. Exploration music (or silence) would then take over. Deleting the battle music would result in neither battle music nor silence ever interrupting any music, as one would expect.

Tested on OpenMW 0.48, on Windows 10, using the english Steam version of Morrowind with Tribunal and Bloodmoon. The problem occurs regardless of mods (barring scripted music mods).