SCI: Fix some issues with ChunkResourceSource

1. The chunk number was hard-coded to zero and inaccessible.
2. Running ResourceManager::getVolumeFile for a chunk resource
   would always return nullptr instead of a stream of the chunk,
   which made it impossible to generically validate that resources
   being added were within bounds of the container file (or, in
   this case, container chunk).

2 files changed, 11 insertions, 1 deletions

diff --git a/engines/sci/resource.cpp b/engines/sci/resource.cpp
index 9a53627df3..0846b93d04 100644
--- a/engines/sci/resource.cpp
+++ b/engines/sci/resource.cpp
@@ -345,6 +345,14 @@ Common::SeekableReadStream *ResourceManager::getVolumeFile(ResourceSource *sourc
 	Common::List<Common::File *>::iterator it = _volumeFiles.begin();
 	Common::File *file;
 
+#ifdef ENABLE_SCI32
+	ChunkResourceSource *chunkSource = dynamic_cast<ChunkResourceSource *>(source);
+	if (chunkSource != nullptr) {
+		Resource *res = findResource(ResourceId(kResourceTypeChunk, chunkSource->getNumber()), false);
+		return res ? res->makeStream() : nullptr;
+	}
+#endif
+
 	if (source->_resourceFile)
 		return source->_resourceFile->createReadStream();
 
@@ -843,7 +851,7 @@ void IntMapResourceSource::scanSource(ResourceManager *resMan) {
 ChunkResourceSource::ChunkResourceSource(const Common::String &name, uint16 number)
 	: ResourceSource(kSourceChunk, name) {
 
-	_number = 0;
+	_number = number;
 }
 
 void ChunkResourceSource::scanSource(ResourceManager *resMan) {
diff --git a/engines/sci/resource_intern.h b/engines/sci/resource_intern.h
index fe4b0a97f4..f198eddeb3 100644
--- a/engines/sci/resource_intern.h
+++ b/engines/sci/resource_intern.h
@@ -204,6 +204,8 @@ public:
 	virtual void scanSource(ResourceManager *resMan);
 	virtual void loadResource(ResourceManager *resMan, Resource *res);
 
+	uint16 getNumber() const { return _number; }
+
 protected:
 	uint16 _number;