Fix for RC bug [780675] MI2: Reoccuring crash

Tightened up OOB track selection handling in
MidiParser. Apparently some SMFs in the Mac
version of MI2 (and other games?) specify
track -1 in their jump commands to indicate
a jump within the same track.

svn-id: r9321

2 files changed, 3 insertions, 3 deletions

diff --git a/scumm/imuse_player.cpp b/scumm/imuse_player.cpp
index 3b9c225043..2257230bdd 100644
--- a/scumm/imuse_player.cpp
+++ b/scumm/imuse_player.cpp
@@ -698,8 +698,8 @@ void Player::key_off(uint8 chan, byte note) {
 bool Player::jump(uint track, uint beat, uint tick) {
 	if (!_parser)
 		return false;
-	_track_index = track;
-	_parser->setTrack (track);
+	if (_parser->setTrack (track))
+		_track_index = track;
 	if (!_parser->jumpToTick ((beat - 1) * TICKS_PER_BEAT + tick))
 		return false;
 	turn_off_pedals();
diff --git a/sound/midiparser.cpp b/sound/midiparser.cpp
index f9d360f6e9..0b2408f4cf 100644
--- a/sound/midiparser.cpp
+++ b/sound/midiparser.cpp
@@ -252,7 +252,7 @@ void MidiParser::resetTracking() {
 }
 
 bool MidiParser::setTrack (int track) {
-	if (track >= _num_tracks)
+	if (track < 0 || track >= _num_tracks)
 		return false;
 	else if (track == _active_track)
 		return true;