From 29b288238108ca34b25a58a9376f418d61e55420 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mikrut?= <mikrutrafal@protonmail.com>
Date: Thu, 31 Dec 2020 15:47:37 +0100
Subject: [PATCH] Do not iterate over map when removing its values

---
 scene/2d/tile_map.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scene/2d/tile_map.cpp b/scene/2d/tile_map.cpp
index 928a839cc1f..cf8f395821a 100644
--- a/scene/2d/tile_map.cpp
+++ b/scene/2d/tile_map.cpp
@@ -1024,7 +1024,9 @@ void TileMap::update_dirty_bitmask() {
 
 void TileMap::fix_invalid_tiles() {
 	ERR_FAIL_COND_MSG(tile_set.is_null(), "Cannot fix invalid tiles if Tileset is not open.");
-	for (Map<PosKey, Cell>::Element *E = tile_map.front(); E; E = E->next()) {
+
+	Map<PosKey, Cell> temp_tile_map = tile_map;
+	for (Map<PosKey, Cell>::Element *E = temp_tile_map.front(); E; E = E->next()) {
 		if (!tile_set->has_tile(get_cell(E->key().x, E->key().y))) {
 			set_cell(E->key().x, E->key().y, INVALID_CELL);
 		}