From 97463309ba623606850b5d3b0baf7c9bdf9b6fba Mon Sep 17 00:00:00 2001
From: Kari Salminen
Date: Tue, 19 Aug 2008 11:55:20 +0000
Subject: Fix for bug #2057637: FW: Spaceship glitches in demo (regression).
 This was caused by assuming in-place decompression is ok, it wasn't, although
 AFAIK the original did decompression in-place too. Changed unpacking to be
 done not in-place and the glitch vanished. Also changed the unpacker to also
 handle uncompressed input data.

svn-id: r34034
---
 engines/cine/part.cpp   | 31 ++++++++++++++-----------------
 engines/cine/unpack.cpp |  8 ++++++++
 engines/cine/unpack.h   |  6 +++---
 3 files changed, 25 insertions(+), 20 deletions(-)

(limited to 'engines')

diff --git a/engines/cine/part.cpp b/engines/cine/part.cpp
index 657471be4e..7679d9d380 100644
--- a/engines/cine/part.cpp
+++ b/engines/cine/part.cpp
@@ -123,13 +123,13 @@ void CineEngine::readVolCnf() {
 		unpackedSize = packedSize = f.size();
 	}
 	uint8 *buf = new uint8[unpackedSize];
-	f.read(buf, packedSize);
-	if (packedSize != unpackedSize) {
-		CineUnpacker cineUnpacker;
-		if (!cineUnpacker.unpack(buf, packedSize, buf, unpackedSize)) {
-			error("Error while unpacking 'vol.cnf' data");
-		}
+	uint8 *packedBuf = new uint8[packedSize];
+	f.read(packedBuf, packedSize);
+	CineUnpacker cineUnpacker;
+	if (!cineUnpacker.unpack(packedBuf, packedSize, buf, unpackedSize)) {
+		error("Error while unpacking 'vol.cnf' data");
 	}
+	delete[] packedBuf;
 	uint8 *p = buf;
 	int resourceFilesCount = READ_BE_UINT16(p); p += 2;
 	int entrySize = READ_BE_UINT16(p); p += 2;
@@ -211,26 +211,23 @@ int16 findFileInBundle(const char *fileName) {
 }
 
 void readFromPart(int16 idx, byte *dataPtr, uint32 maxSize) {
+	assert(maxSize >= partBuffer[idx].packedSize);
 	setMouseCursor(MOUSE_CURSOR_DISK);
 
 	g_cine->_partFileHandle.seek(partBuffer[idx].offset, SEEK_SET);
-	g_cine->_partFileHandle.read(dataPtr, MIN(partBuffer[idx].packedSize, maxSize));
+	g_cine->_partFileHandle.read(dataPtr, partBuffer[idx].packedSize);
 }
 
 byte *readBundleFile(int16 foundFileIdx, uint32 *size) {
 	assert(foundFileIdx >= 0 && foundFileIdx < (int32)partBuffer.size());
 	bool error = false;
 	byte *dataPtr = (byte *)calloc(partBuffer[foundFileIdx].unpackedSize, 1);
-	readFromPart(foundFileIdx, dataPtr, partBuffer[foundFileIdx].unpackedSize);
-	if (partBuffer[foundFileIdx].unpackedSize > partBuffer[foundFileIdx].packedSize) {
-		CineUnpacker cineUnpacker;
-		error = !cineUnpacker.unpack(dataPtr, partBuffer[foundFileIdx].packedSize, dataPtr, partBuffer[foundFileIdx].unpackedSize);
-	} else if (partBuffer[foundFileIdx].unpackedSize < partBuffer[foundFileIdx].packedSize) {
-		// Unpacked size of a file should never be less than its packed size
-		error = true;
-	} else { // partBuffer[foundFileIdx].unpackedSize == partBuffer[foundFileIdx].packedSize
-		debugC(5, kCineDebugPart, "Loaded non-compressed file '%s' from bundle file '%s'", partBuffer[foundFileIdx].partName, currentPartName);
-	}
+	byte *packedData = (byte *)calloc(partBuffer[foundFileIdx].packedSize, 1);
+	assert(dataPtr && packedData);
+	readFromPart(foundFileIdx, packedData, partBuffer[foundFileIdx].packedSize);
+	CineUnpacker cineUnpacker;
+	error = !cineUnpacker.unpack(packedData, partBuffer[foundFileIdx].packedSize, dataPtr, partBuffer[foundFileIdx].unpackedSize);
+	free(packedData);
 
 	if (error) {
 		warning("Error unpacking '%s' from bundle file '%s'", partBuffer[foundFileIdx].partName, currentPartName);
diff --git a/engines/cine/unpack.cpp b/engines/cine/unpack.cpp
index 5d85ff6cab..7915fd1cf8 100644
--- a/engines/cine/unpack.cpp
+++ b/engines/cine/unpack.cpp
@@ -100,6 +100,14 @@ bool CineUnpacker::unpack(const byte *src, uint srcLen, byte *dst, uint dstLen)
 	_dstBegin = dst;
 	_dstEnd   = dst + dstLen;
 
+	// Handle already unpacked data here
+	if (srcLen == dstLen) {
+		// Source length is same as destination length so the source
+		// data is already unpacked. Let's just copy it then.
+		memcpy(dst, src, srcLen);
+		return true;
+	}
+
 	// Initialize other variables
 	_src = _srcBegin + srcLen - 4;
 	uint32 unpackedLength = readSource(); // Unpacked length in bytes
diff --git a/engines/cine/unpack.h b/engines/cine/unpack.h
index e16cb594a9..2355df5ee1 100644
--- a/engines/cine/unpack.h
+++ b/engines/cine/unpack.h
@@ -35,14 +35,14 @@ namespace Cine {
  * A LZ77 style decompressor for Delphine's data files
  * used in at least Future Wars and Operation Stealth.
  * @note Works backwards in the source and destination buffers.
- * @note Can work with source and destination in the same buffer if there's space.
+ * @warning Having the source and destination in the same buffer when unpacking can cause errors!
  */
 class CineUnpacker {
 public:
 	/**
 	 * Unpacks packed data from the source buffer to the destination buffer.
-	 * @warning Do NOT call this on data that is not packed.
-	 * @note Source and destination buffer pointers can be the same as long as there's space for the unpacked data.
+	 * @note You may call this on already unpacked data but then source length must be equal to destination length.
+	 * @warning The source and destination should not point to the same buffer. If they do, errors may occur!
 	 * @param src Pointer to the source buffer.
 	 * @param srcLen Length of the source buffer.
 	 * @param dst Pointer to the destination buffer.
-- 
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