Keep PlayerMetaRef via name not pointer

src/script/lua_api/l_playermeta.h

@@ -24,12 +24,14 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "lua_api/l_metadata.h"
 #include "irrlichttypes_bloated.h"
 #include "inventory.h"
-#include "metadata.h"
+
+class ServerEnvironment;
 
 class PlayerMetaRef : public MetaDataRef
 {
 private:
-	IMetadata *metadata = nullptr;
+	ServerEnvironment *m_env;
+	std::string m_name;
 
 	static const luaL_Reg methods[];
 
@@ -40,12 +42,17 @@ class PlayerMetaRef : public MetaDataRef
 	virtual void reportMetadataChange(const std::string *name = nullptr);
 
 public:
-	PlayerMetaRef(IMetadata *metadata) : metadata(metadata) {}
+	PlayerMetaRef(ServerEnvironment *env, std::string_view name) :
+		m_env(env), m_name(name)
+	{
+		assert(m_env);
+		assert(!m_name.empty());
+	}
 	~PlayerMetaRef() = default;
 
-	// Creates an ItemStackMetaRef and leaves it on top of stack
+	// Creates an PlayerMetaRef and leaves it on top of stack
 	// Not callable from Lua; all references are created on the C side.
-	static void create(lua_State *L, IMetadata *metadata);
+	static void create(lua_State *L, ServerEnvironment *env, std::string_view name);
 
 	static void Register(lua_State *L);