Get rid of node metadata when it becomes empty

fixes #8943

2 files changed, 12 insertions, 7 deletions

diff --git a/src/script/lua_api/l_nodemeta.cpp b/src/script/lua_api/l_nodemeta.cpp
index 1d052685e..514a1b78b 100644
--- a/src/script/lua_api/l_nodemeta.cpp
+++ b/src/script/lua_api/l_nodemeta.cpp
@@ -40,7 +40,7 @@ NodeMetaRef* NodeMetaRef::checkobject(lua_State *L, int narg)
 Metadata* NodeMetaRef::getmeta(bool auto_create)
 {
 	if (m_is_local)
-		return m_meta;
+		return m_local_meta;
 
 	NodeMetadata *meta = m_env->getMap().getNodeMetadata(m_p);
 	if (meta == NULL && auto_create) {
@@ -62,9 +62,12 @@ void NodeMetaRef::clearMeta()
 void NodeMetaRef::reportMetadataChange(const std::string *name)
 {
 	SANITY_CHECK(!m_is_local);
-	// NOTE: This same code is in rollback_interface.cpp
 	// Inform other things that the metadata has changed
-	NodeMetadata *meta = dynamic_cast<NodeMetadata*>(m_meta);
+	NodeMetadata *meta = dynamic_cast<NodeMetadata*>(getmeta(false));
+
+	// If the metadata is now empty, get rid of it
+	if (meta && meta->empty())
+		clearMeta();
 
 	MapEditEvent event;
 	event.type = MEET_BLOCK_NODE_METADATA_CHANGED;
@@ -174,8 +177,8 @@ NodeMetaRef::NodeMetaRef(v3s16 p, ServerEnvironment *env):
 }
 
 NodeMetaRef::NodeMetaRef(Metadata *meta):
-	m_meta(meta),
-	m_is_local(true)
+	m_is_local(true),
+	m_local_meta(meta)
 {
 }
 
diff --git a/src/script/lua_api/l_nodemeta.h b/src/script/lua_api/l_nodemeta.h
index fdc1766ed..265ece3d0 100644
--- a/src/script/lua_api/l_nodemeta.h
+++ b/src/script/lua_api/l_nodemeta.h
@@ -33,10 +33,12 @@ class NodeMetadata;
 
 class NodeMetaRef : public MetaDataRef {
 private:
+	bool m_is_local = false;
+	// Set for server metadata
 	v3s16 m_p;
 	ServerEnvironment *m_env = nullptr;
-	Metadata *m_meta = nullptr;
-	bool m_is_local = false;
+	// Set for client metadata
+	Metadata *m_local_meta = nullptr;
 
 	static const char className[];
 	static const luaL_Reg methodsServer[];