Add safe-guard against collision of animation IDs.

When debugging another issue, I preloaded all animations, and horrible things
happened that I debugged for a few hours.

svn-id: r45695

2 files changed, 10 insertions, 0 deletions

diff --git a/engines/draci/animation.cpp b/engines/draci/animation.cpp
index 2bbb960fb1..674e2473df 100644
--- a/engines/draci/animation.cpp
+++ b/engines/draci/animation.cpp
@@ -63,6 +63,9 @@ void Animation::setLooping(bool looping) {
 }
 
 void Animation::markDirtyRect(Surface *surface) const {
+	if (getFrameCount() == 0)
+		return;
+
 	// Fetch the current frame's rectangle
 	Drawable *frame = _frames[_currentFrame];
 	Common::Rect frameRect = frame->getRect(_displacement);
diff --git a/engines/draci/game.cpp b/engines/draci/game.cpp
index 7516da3c03..0d9e41f125 100644
--- a/engines/draci/game.cpp
+++ b/engines/draci/game.cpp
@@ -1166,6 +1166,13 @@ void Game::loadRoom(int roomNum) {
 }
 
 int Game::loadAnimation(uint animNum, uint z) {
+	// Make double-sure that an animation isn't loaded more than twice,
+	// otherwise horrible things happen in the AnimationManager, because
+	// they use a simple link-list without duplicate checking.  This should
+	// never happen unless there is a bug in the game, because all GPL2
+	// commands are guarded.
+	assert(!_vm->_anims->getAnimation(animNum));
+
 	const BAFile *animFile = _vm->_animationsArchive->getFile(animNum);
 	Common::MemoryReadStream animationReader(animFile->_data, animFile->_length);