diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index 48207da1f..2442799c7 100644
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -241,7 +241,7 @@ void ContentFeatures::reset()
 	sound_dug = SimpleSoundSpec();
 }
 
-void ContentFeatures::serialize(std::ostream &os, u16 protocol_version)
+void ContentFeatures::serialize(std::ostream &os, u16 protocol_version) const
 {
 	if(protocol_version < 24){
 		serializeOld(os, protocol_version);
@@ -398,9 +398,9 @@ public:
 	virtual content_t allocateDummy(const std::string &name);
 	virtual void updateAliases(IItemDefManager *idef);
 	virtual void updateTextures(IGameDef *gamedef,
-	/*argument: */void (*progress_callback)(void *progress_args, u32 progress, u32 max_progress),
-	/*argument: */void *progress_callback_args);
-	void serialize(std::ostream &os, u16 protocol_version);
+		void (*progress_cbk)(void *progress_args, u32 progress, u32 max_progress),
+		void *progress_cbk_args);
+	void serialize(std::ostream &os, u16 protocol_version) const;
 	void deSerialize(std::istream &is);
 
 	inline virtual bool getNodeRegistrationStatus() const;
@@ -409,6 +409,7 @@ public:
 	virtual void pendNodeResolve(NodeResolver *nr, NodeResolveMethod how);
 	virtual bool cancelNodeResolveCallback(NodeResolver *nr);
 	virtual void runNodeResolveCallbacks();
+	virtual void resetNodeResolveState();
 
 private:
 	void addNameIdMapping(content_t i, std::string name);
@@ -474,8 +475,7 @@ void CNodeDefManager::clear()
 	m_group_to_items.clear();
 	m_next_id = 0;
 
-	m_node_registration_complete = false;
-	m_pending_resolve_callbacks.clear();
+	resetNodeResolveState();
 
 	u32 initial_length = 0;
 	initial_length = MYMAX(initial_length, CONTENT_UNKNOWN + 1);
@@ -972,7 +972,7 @@ void CNodeDefManager::fillTileAttribs(ITextureSource *tsrc, TileSpec *tile,
 #endif
 
 
-void CNodeDefManager::serialize(std::ostream &os, u16 protocol_version)
+void CNodeDefManager::serialize(std::ostream &os, u16 protocol_version) const
 {
 	writeU8(os, 1); // version
 	u16 count = 0;
@@ -981,7 +981,7 @@ void CNodeDefManager::serialize(std::ostream &os, u16 protocol_version)
 		if (i == CONTENT_IGNORE || i == CONTENT_AIR
 				|| i == CONTENT_UNKNOWN)
 			continue;
-		ContentFeatures *f = &m_content_features[i];
+		const ContentFeatures *f = &m_content_features[i];
 		if (f->name == "")
 			continue;
 		writeU16(os2, i);
@@ -1062,7 +1062,7 @@ IWritableNodeDefManager *createNodeDefManager()
 
 
 //// Serialization of old ContentFeatures formats
-void ContentFeatures::serializeOld(std::ostream &os, u16 protocol_version)
+void ContentFeatures::serializeOld(std::ostream &os, u16 protocol_version) const
 {
 	if (protocol_version == 13)
 	{
@@ -1342,6 +1342,13 @@ void CNodeDefManager::runNodeResolveCallbacks()
 }
 
 
+void CNodeDefManager::resetNodeResolveState()
+{
+	m_node_registration_complete = false;
+	m_pending_resolve_callbacks.clear();
+}
+
+
 ////
 //// NodeResolver
 ////
diff --git a/src/nodedef.h b/src/nodedef.h
index d9829c495..42b345059 100644
--- a/src/nodedef.h
+++ b/src/nodedef.h
@@ -265,9 +265,9 @@ struct ContentFeatures
 	ContentFeatures();
 	~ContentFeatures();
 	void reset();
-	void serialize(std::ostream &os, u16 protocol_version);
+	void serialize(std::ostream &os, u16 protocol_version) const;
 	void deSerialize(std::istream &is);
-	void serializeOld(std::ostream &os, u16 protocol_version);
+	void serializeOld(std::ostream &os, u16 protocol_version) const;
 	void deSerializeOld(std::istream &is, int version);
 
 	/*
@@ -288,48 +288,44 @@ enum NodeResolveMethod {
 	NODE_RESOLVE_DEFERRED,
 };
 
-class INodeDefManager
-{
+class INodeDefManager {
 public:
 	INodeDefManager(){}
 	virtual ~INodeDefManager(){}
 	// Get node definition
-	virtual const ContentFeatures& get(content_t c) const=0;
-	virtual const ContentFeatures& get(const MapNode &n) const=0;
+	virtual const ContentFeatures &get(content_t c) const=0;
+	virtual const ContentFeatures &get(const MapNode &n) const=0;
 	virtual bool getId(const std::string &name, content_t &result) const=0;
 	virtual content_t getId(const std::string &name) const=0;
 	// Allows "group:name" in addition to regular node names
 	virtual void getIds(const std::string &name, std::set<content_t> &result)
 			const=0;
-	virtual const ContentFeatures& get(const std::string &name) const=0;
+	virtual const ContentFeatures &get(const std::string &name) const=0;
 
-	virtual void serialize(std::ostream &os, u16 protocol_version)=0;
+	virtual void serialize(std::ostream &os, u16 protocol_version) const=0;
 
 	virtual bool getNodeRegistrationStatus() const=0;
-	virtual void setNodeRegistrationStatus(bool completed)=0;
 
 	virtual void pendNodeResolve(NodeResolver *nr, NodeResolveMethod how)=0;
 	virtual bool cancelNodeResolveCallback(NodeResolver *nr)=0;
-	virtual void runNodeResolveCallbacks()=0;
 };
 
-class IWritableNodeDefManager : public INodeDefManager
-{
+class IWritableNodeDefManager : public INodeDefManager {
 public:
 	IWritableNodeDefManager(){}
 	virtual ~IWritableNodeDefManager(){}
 	virtual IWritableNodeDefManager* clone()=0;
 	// Get node definition
-	virtual const ContentFeatures& get(content_t c) const=0;
-	virtual const ContentFeatures& get(const MapNode &n) const=0;
+	virtual const ContentFeatures &get(content_t c) const=0;
+	virtual const ContentFeatures &get(const MapNode &n) const=0;
 	virtual bool getId(const std::string &name, content_t &result) const=0;
 	// If not found, returns CONTENT_IGNORE
 	virtual content_t getId(const std::string &name) const=0;
 	// Allows "group:name" in addition to regular node names
 	virtual void getIds(const std::string &name, std::set<content_t> &result)
-			const=0;
+		const=0;
 	// If not found, returns the features of CONTENT_UNKNOWN
-	virtual const ContentFeatures& get(const std::string &name) const=0;
+	virtual const ContentFeatures &get(const std::string &name) const=0;
 
 	// Register node definition by name (allocate an id)
 	// If returns CONTENT_IGNORE, could not allocate id
@@ -348,10 +344,10 @@ public:
 		Update tile textures to latest return values of TextueSource.
 	*/
 	virtual void updateTextures(IGameDef *gamedef,
-	/*argument: */void (*progress_callback)(void *progress_args, u32 progress, u32 max_progress),
-	/*argument: */void *progress_callback_args)=0;
+		void (*progress_cbk)(void *progress_args, u32 progress, u32 max_progress),
+		void *progress_cbk_args)=0;
 
-	virtual void serialize(std::ostream &os, u16 protocol_version)=0;
+	virtual void serialize(std::ostream &os, u16 protocol_version) const=0;
 	virtual void deSerialize(std::istream &is)=0;
 
 	virtual bool getNodeRegistrationStatus() const=0;
@@ -360,6 +356,7 @@ public:
 	virtual void pendNodeResolve(NodeResolver *nr, NodeResolveMethod how)=0;
 	virtual bool cancelNodeResolveCallback(NodeResolver *nr)=0;
 	virtual void runNodeResolveCallbacks()=0;
+	virtual void resetNodeResolveState()=0;
 };
 
 IWritableNodeDefManager *createNodeDefManager();
diff --git a/src/unittest/test_noderesolver.cpp b/src/unittest/test_noderesolver.cpp
index c440b2399..a4ea647bc 100644
--- a/src/unittest/test_noderesolver.cpp
+++ b/src/unittest/test_noderesolver.cpp
@@ -31,36 +31,30 @@ public:
 
 	void runTests(IGameDef *gamedef);
 
-	void testNodeResolving(INodeDefManager *ndef);
-	void testPendingResolveCancellation(INodeDefManager *ndef);
-	void testDirectResolveMethod(INodeDefManager *ndef);
-	void testNoneResolveMethod(INodeDefManager *ndef);
+	void testNodeResolving(IWritableNodeDefManager *ndef);
+	void testPendingResolveCancellation(IWritableNodeDefManager *ndef);
+	void testDirectResolveMethod(IWritableNodeDefManager *ndef);
+	void testNoneResolveMethod(IWritableNodeDefManager *ndef);
 };
 
 static TestNodeResolver g_test_instance;
 
 void TestNodeResolver::runTests(IGameDef *gamedef)
 {
-	IWritableNodeDefManager *parent_ndef;
-	INodeDefManager *ndef;
+	IWritableNodeDefManager *ndef =
+		(IWritableNodeDefManager *)gamedef->getNodeDefManager();
 
-	parent_ndef = (IWritableNodeDefManager *)gamedef->getNodeDefManager();
-
-	ndef = parent_ndef->clone();
+	ndef->resetNodeResolveState();
 	TEST(testNodeResolving, ndef);
-	delete ndef;
 
-	ndef = parent_ndef->clone();
+	ndef->resetNodeResolveState();
 	TEST(testPendingResolveCancellation, ndef);
-	delete ndef;
 
-	ndef = parent_ndef->clone();
+	ndef->resetNodeResolveState();
 	TEST(testDirectResolveMethod, ndef);
-	delete ndef;
 
-	ndef = parent_ndef->clone();
+	ndef->resetNodeResolveState();
 	TEST(testNoneResolveMethod, ndef);
-	delete ndef;
 }
 
 class Foobar : public NodeResolver {
@@ -113,7 +107,7 @@ void Foobaz::resolveNodeNames()
 }
 
 
-void TestNodeResolver::testNodeResolving(INodeDefManager *ndef)
+void TestNodeResolver::testNodeResolving(IWritableNodeDefManager *ndef)
 {
 	Foobar foobar;
 	size_t i;
@@ -191,7 +185,7 @@ void TestNodeResolver::testNodeResolving(INodeDefManager *ndef)
 }
 
 
-void TestNodeResolver::testPendingResolveCancellation(INodeDefManager *ndef)
+void TestNodeResolver::testPendingResolveCancellation(IWritableNodeDefManager *ndef)
 {
 	Foobaz foobaz1;
 	foobaz1.test_content1 = 1234;
@@ -219,7 +213,7 @@ void TestNodeResolver::testPendingResolveCancellation(INodeDefManager *ndef)
 }
 
 
-void TestNodeResolver::testDirectResolveMethod(INodeDefManager *ndef)
+void TestNodeResolver::testDirectResolveMethod(IWritableNodeDefManager *ndef)
 {
 	Foobaz foobaz;
 
@@ -240,7 +234,7 @@ void TestNodeResolver::testDirectResolveMethod(INodeDefManager *ndef)
 }
 
 
-void TestNodeResolver::testNoneResolveMethod(INodeDefManager *ndef)
+void TestNodeResolver::testNoneResolveMethod(IWritableNodeDefManager *ndef)
 {
 	Foobaz foobaz;