6 files changed, 69 insertions, 2 deletions

diff --git a/src/itemdef.cpp b/src/itemdef.cpp
index a618ad631..a6c627a03 100644
--- a/src/itemdef.cpp
+++ b/src/itemdef.cpp
@@ -466,11 +466,17 @@ public:
 			infostream<<"ItemDefManager: erased alias "<<def.name
 					<<" because item was defined"<<std::endl;
 	}
+	virtual void unregisterItem(const std::string &name)
+	{
+		verbosestream<<"ItemDefManager: unregistering \""<<name<<"\""<<std::endl;
+
+		delete m_item_definitions[name];
+		m_item_definitions.erase(name);
+	}
 	virtual void registerAlias(const std::string &name,
 			const std::string &convert_to)
 	{
-		if(m_item_definitions.find(name) == m_item_definitions.end())
-		{
+		if (m_item_definitions.find(name) == m_item_definitions.end()) {
 			verbosestream<<"ItemDefManager: setting alias "<<name
 				<<" -> "<<convert_to<<std::endl;
 			m_aliases[name] = convert_to;
diff --git a/src/itemdef.h b/src/itemdef.h
index 805b4aa5d..b14ed41f7 100644
--- a/src/itemdef.h
+++ b/src/itemdef.h
@@ -144,6 +144,7 @@ public:
 	virtual void clear()=0;
 	// Register item definition
 	virtual void registerItem(const ItemDefinition &def)=0;
+	virtual void unregisterItem(const std::string &name)=0;
 	// Set an alias so that items named <name> will load as <convert_to>.
 	// Alias is not set if <name> has already been defined.
 	// Alias will be removed if <name> is defined at a later point of time.
diff --git a/src/nodedef.cpp b/src/nodedef.cpp
index 646375575..bfb2999bd 100644
--- a/src/nodedef.cpp
+++ b/src/nodedef.cpp
@@ -778,6 +778,7 @@ public:
 	content_t allocateId();
 	virtual content_t set(const std::string &name, const ContentFeatures &def);
 	virtual content_t allocateDummy(const std::string &name);
+	virtual void removeNode(const std::string &name);
 	virtual void updateAliases(IItemDefManager *idef);
 	virtual void applyTextureOverrides(const std::string &override_filepath);
 	virtual void updateTextures(IGameDef *gamedef,
@@ -1072,6 +1073,40 @@ content_t CNodeDefManager::allocateDummy(const std::string &name)
 }
 
 
+void CNodeDefManager::removeNode(const std::string &name)
+{
+	// Pre-condition
+	assert(name != "");
+
+	// Erase name from name ID mapping
+	content_t id = CONTENT_IGNORE;
+	if (m_name_id_mapping.getId(name, id)) {
+		m_name_id_mapping.eraseName(name);
+		m_name_id_mapping_with_aliases.erase(name);
+	}
+
+	// Erase node content from all groups it belongs to
+	for (std::map<std::string, GroupItems>::iterator iter_groups =
+			m_group_to_items.begin();
+			iter_groups != m_group_to_items.end();) {
+		GroupItems &items = iter_groups->second;
+		for (GroupItems::iterator iter_groupitems = items.begin();
+				iter_groupitems != items.end();) {
+			if (iter_groupitems->first == id)
+				items.erase(iter_groupitems++);
+			else
+				iter_groupitems++;
+		}
+
+		// Check if group is empty
+		if (items.size() == 0)
+			m_group_to_items.erase(iter_groups++);
+		else
+			iter_groups++;
+	}
+}
+
+
 void CNodeDefManager::updateAliases(IItemDefManager *idef)
 {
 	std::set<std::string> all = idef->getAll();
diff --git a/src/nodedef.h b/src/nodedef.h
index f17c53727..80396f992 100644
--- a/src/nodedef.h
+++ b/src/nodedef.h
@@ -384,6 +384,8 @@ public:
 			const ContentFeatures &def)=0;
 	// If returns CONTENT_IGNORE, could not allocate id
 	virtual content_t allocateDummy(const std::string &name)=0;
+	// Remove a node
+	virtual void removeNode(const std::string &name)=0;
 
 	/*
 		Update item alias mapping.
diff --git a/src/script/lua_api/l_item.cpp b/src/script/lua_api/l_item.cpp
index 5381cba76..ff0baea14 100644
--- a/src/script/lua_api/l_item.cpp
+++ b/src/script/lua_api/l_item.cpp
@@ -525,6 +525,27 @@ int ModApiItemMod::l_register_item_raw(lua_State *L)
 	return 0; /* number of results */
 }
 
+// unregister_item(name)
+int ModApiItemMod::l_unregister_item_raw(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	std::string name = luaL_checkstring(L, 1);
+
+	IWritableItemDefManager *idef =
+			getServer(L)->getWritableItemDefManager();
+
+	// Unregister the node
+	if (idef->get(name).type == ITEM_NODE) {
+		IWritableNodeDefManager *ndef =
+			getServer(L)->getWritableNodeDefManager();
+		ndef->removeNode(name);
+	}
+
+	idef->unregisterItem(name);
+
+	return 0; /* number of results */
+}
+
 // register_alias_raw(name, convert_to_name)
 int ModApiItemMod::l_register_alias_raw(lua_State *L)
 {
@@ -570,6 +591,7 @@ int ModApiItemMod::l_get_name_from_content_id(lua_State *L)
 void ModApiItemMod::Initialize(lua_State *L, int top)
 {
 	API_FCT(register_item_raw);
+	API_FCT(unregister_item_raw);
 	API_FCT(register_alias_raw);
 	API_FCT(get_content_id);
 	API_FCT(get_name_from_content_id);
diff --git a/src/script/lua_api/l_item.h b/src/script/lua_api/l_item.h
index 0f9e4ba9b..be919b701 100644
--- a/src/script/lua_api/l_item.h
+++ b/src/script/lua_api/l_item.h
@@ -135,6 +135,7 @@ public:
 class ModApiItemMod : public ModApiBase {
 private:
 	static int l_register_item_raw(lua_State *L);
+	static int l_unregister_item_raw(lua_State *L);
 	static int l_register_alias_raw(lua_State *L);
 	static int l_get_content_id(lua_State *L);
 	static int l_get_name_from_content_id(lua_State *L);