CINE: Fix CollisionPage Uninitialised Reads in Operation Stealth.

The collisionPage is only initialised with values when loadCtFw() / loadCtOS() is called.
However, currently during the display of the Delphine Software Logo in Operation Stealth,
checkCollision() is called, but the collisionPage has not been loaded.
To fix the invalid reads, have added code to set the page to zero after allocation.
Shouldn't cause any issues to FW as this will load over the top anyway.

Have also added debug output around this behaviour so that if this is not sufficient i.e. a collision page load is actually missing, then this will aid investigation.

svn-id: r55071

4 files changed, 21 insertions, 7 deletions

diff --git a/engines/cine/bg.cpp b/engines/cine/bg.cpp
index 449e254021..1c6a55c270 100644
--- a/engines/cine/bg.cpp
+++ b/engines/cine/bg.cpp
@@ -38,6 +38,7 @@ byte *additionalBgTable[9];
 int16 currentAdditionalBgIdx = 0, currentAdditionalBgIdx2 = 0;
 
 byte loadCtFW(const char *ctName) {
+	debugC(1, kCineDebugCollision, "loadCtFW(\"%s\")", ctName);
 	uint16 header[32];
 	byte *ptr, *dataPtr;
 
@@ -71,12 +72,21 @@ byte loadCtFW(const char *ctName) {
 }
 
 byte loadCtOS(const char *ctName) {
+	debugC(1, kCineDebugCollision, "loadCtOS(\"%s\")", ctName);
 	byte *ptr, *dataPtr;
 
+	int16 foundFileIdx = findFileInBundle(ctName);
+	if (foundFileIdx == -1) {
+		warning("loadCtOS: Unable to find collision data file '%s'", ctName);
+		// FIXME: Rework this function's return value policy and return an appropriate value here.
+		// The return value isn't yet used for anything so currently it doesn't really matter.
+		return 0;
+	}
+
 	if (currentCtName != ctName)
 		strcpy(currentCtName, ctName);
 
-	ptr = dataPtr = readBundleFile(findFileInBundle(ctName));
+	ptr = dataPtr = readBundleFile(foundFileIdx);
 
 	uint16 bpp = READ_BE_UINT16(ptr);
 	ptr += 2;
diff --git a/engines/cine/cine.cpp b/engines/cine/cine.cpp
index 38a0eda13e..5498b0f977 100644
--- a/engines/cine/cine.cpp
+++ b/engines/cine/cine.cpp
@@ -53,9 +53,10 @@ Sound *g_sound = 0;
 CineEngine *g_cine = 0;
 
 CineEngine::CineEngine(OSystem *syst, const CINEGameDescription *gameDesc) : Engine(syst), _gameDescription(gameDesc) {
-	DebugMan.addDebugChannel(kCineDebugScript, "Script", "Script debug level");
-	DebugMan.addDebugChannel(kCineDebugPart,   "Part",   "Part debug level");
-	DebugMan.addDebugChannel(kCineDebugSound,  "Sound",  "Sound debug level");
+	DebugMan.addDebugChannel(kCineDebugScript,    "Script",    "Script debug level");
+	DebugMan.addDebugChannel(kCineDebugPart,      "Part",      "Part debug level");
+	DebugMan.addDebugChannel(kCineDebugSound,     "Sound",     "Sound debug level");
+	DebugMan.addDebugChannel(kCineDebugCollision, "Collision", "Collision debug level");
 	_console = new CineConsole(this);
 
 	// Setup mixer
@@ -161,6 +162,7 @@ void CineEngine::initialize() {
 	renderer->initialize();
 
 	collisionPage = new byte[320 * 200];
+	memset(collisionPage, 0, 320 * 200);
 
 	// Clear part buffer as there's nothing loaded into it yet.
 	// Its size will change when loading data into it with the loadPart function.
diff --git a/engines/cine/cine.h b/engines/cine/cine.h
index dd00d9b206..5f49a2907f 100644
--- a/engines/cine/cine.h
+++ b/engines/cine/cine.h
@@ -217,9 +217,10 @@ enum {
 };
 
 enum {
-	kCineDebugScript = 1 << 0,
-	kCineDebugPart   = 1 << 1,
-	kCineDebugSound  = 1 << 2
+	kCineDebugScript    = 1 << 0,
+	kCineDebugPart      = 1 << 1,
+	kCineDebugSound     = 1 << 2,
+	kCineDebugCollision = 1 << 3
 };
 
 enum {
diff --git a/engines/cine/script_fw.cpp b/engines/cine/script_fw.cpp
index 7bd0d99e46..3574a1b73a 100644
--- a/engines/cine/script_fw.cpp
+++ b/engines/cine/script_fw.cpp
@@ -1915,6 +1915,7 @@ int16 getZoneFromPositionRaw(byte *page, int16 x, int16 y, int16 width) {
 }
 
 int16 checkCollision(int16 objIdx, int16 x, int16 y, int16 numZones, int16 zoneIdx) {
+	debugC(1, kCineDebugCollision, "checkCollision(objIdx: %d x: %d y:%d numZones:%d zoneIdx: %d)", objIdx, x, y, numZones, zoneIdx);
 	int16 lx = g_cine->_objectTable[objIdx].x + x;
 	int16 ly = g_cine->_objectTable[objIdx].y + y;
 	int16 idx;