add ENTITY_NONE, ENTITY_AUTO reserved entity id & update player.set_entity(...)

src/objects/Player.cpp

@@ -62,7 +62,7 @@ Player::Player(
 Player::~Player() = default;
 
 void Player::updateEntity() {
-    if (eid == 0) {
+    if (eid == ENTITY_AUTO) {
         auto& def = level.content.entities.require("base:player");
         eid = level.entities->spawn(def, getPosition());
         if (auto entity = level.entities->get(eid)) {
@@ -73,7 +73,7 @@ void Player::updateEntity() {
         if (auto entity = level.entities->get(eid)) {
             entity->setPlayer(id);
         }
-    } else if (chunks->getChunkByVoxel(position)) {
+    } else if (chunks->getChunkByVoxel(position) && eid != ENTITY_NONE) {
         logger.error() << "player entity despawned or deleted; "
                           "will be respawned";
         eid = 0;