Fix bad endian bug in thumbnails code

svn-id: r18256

3 files changed, 13 insertions, 6 deletions

diff --git a/scumm/saveload.cpp b/scumm/saveload.cpp
index d276c8257a..ab050a7673 100644
--- a/scumm/saveload.cpp
+++ b/scumm/saveload.cpp
@@ -130,8 +130,12 @@ bool ScummEngine::loadState(int slot, bool compat) {
 	
 	// Since version 52 a thumbnail is saved directly after the header
 	if (hdr.ver >= VER(52)) {
-		uint32 type = in->readUint32BE();
-		if (type != MKID('THMB')) {
+		uint32 type;
+		in->read(&type, 4);
+
+		// Check for the THMB header. Also, work around a bug which caused
+		// the chunk type (incorrectly) to be written in LE on LE machines.
+		if (! (type == MKID('THMB') || (hdr.ver < VER(55) && type == MKID('BMHT')))){
 			warning("Can not load thumbnail");
 			delete in;
 			return false;
diff --git a/scumm/saveload.h b/scumm/saveload.h
index ac0528c834..faee798a9f 100644
--- a/scumm/saveload.h
+++ b/scumm/saveload.h
@@ -45,7 +45,7 @@ namespace Scumm {
  * only saves/loads those which are valid for the version of the savegame
  * which is being loaded/saved currently.
  */
-#define CURRENT_VER 54
+#define CURRENT_VER 55
 
 /**
  * An auxillary macro, used to specify savegame versions. We use this instead
diff --git a/scumm/thumbnail.cpp b/scumm/thumbnail.cpp
index 81aa830ce4..701b651b31 100644
--- a/scumm/thumbnail.cpp
+++ b/scumm/thumbnail.cpp
@@ -56,8 +56,11 @@ inline void colorToRGB(uint16 color, uint8 &r, uint8 &g, uint8 &b) {
 
 Graphics::Surface *ScummEngine::loadThumbnail(Common::InSaveFile *file) {
 	ThumbnailHeader header;
-	header.type = file->readUint32BE();
-	if (header.type != MKID('THMB'))
+	file->read(&header.type, 4);
+	// We also accept the bad 'BMHT' header here, for the sake of compatibility
+	// with some older savegames which were written incorrectly due to a bug in
+	// ScummVM which wrote the thumb header type incorrectly on LE systems.
+	if (header.type != MKID('THMB') && header.type != MKID('BMHT'))
 		return 0;
 
 	header.size = file->readUint32BE();
@@ -111,7 +114,7 @@ void ScummEngine::saveThumbnail(Common::OutSaveFile *file) {
 	header.height = thumb.h;
 	header.bpp = thumb.bytesPerPixel;
 
-	file->writeUint32BE(header.type);
+	file->write(&header.type, 4);
 	file->writeUint32BE(header.size);
 	file->writeByte(header.version);
 	file->writeUint16BE(header.width);