SCI: fix thread lockup issue when loading savegames using a sound driver which depends on the mixer thread for timer calls.

The issues seems to be known. See comments (not by me) in SciMusic::clearPlayList().
For the same reason mentioned there the mutex may also not be locked before calling clearPlayList().

1 files changed, 4 insertions, 3 deletions

diff --git a/engines/sci/engine/savegame.cpp b/engines/sci/engine/savegame.cpp
index c30518ab42..030c0f3f54 100644
--- a/engines/sci/engine/savegame.cpp
+++ b/engines/sci/engine/savegame.cpp
@@ -545,8 +545,6 @@ void DataStack::saveLoadWithSerializer(Common::Serializer &s) {
 void SciMusic::saveLoadWithSerializer(Common::Serializer &s) {
 	// Sync song lib data. When loading, the actual song lib will be initialized
 	// afterwards in gamestate_restore()
-	Common::StackLock lock(_mutex);
-
 	int songcount = 0;
 	byte masterVolume = soundGetMasterVolume();
 	byte reverb = _pMidiDrv->getReverb();
@@ -576,9 +574,12 @@ void SciMusic::saveLoadWithSerializer(Common::Serializer &s) {
 		songcount = _playList.size();
 	s.syncAsUint32LE(songcount);
 
-	if (s.isLoading()) {
+	if (s.isLoading())
 		clearPlayList();
 
+	Common::StackLock lock(_mutex);
+
+	if (s.isLoading()) {
 		for (int i = 0; i < songcount; i++) {
 			MusicEntry *curSong = new MusicEntry();
 			curSong->saveLoadWithSerializer(s);