Fix Table::raw_len

src/table.rs

@@ -147,10 +147,8 @@ impl<'a> Table<'a> {
         let s = self.state.state_ptr();
         unsafe {
             self.lref.push_to_lua_stack(self.state)?;
-            lua::lua_rawlen(s, -1);
-            
-            let len = lua::lua_tonumber(s, -1);
-            lua::lua_pop(self.state.state_ptr(), -1);
+            let len = lua::lua_rawlen(s, -1);
+            lua::lua_pop(s, -1); // pop table
             
             Ok(len as u64)
         }