From a088f7615b1c9f22b03dc7a7e60149eb1226bd32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Janiszewski?=
 <janisozaur@users.noreply.github.com>
Date: Thu, 2 May 2024 18:14:22 +0200
Subject: [PATCH] Fix #21748: TileElement out of bounds (#21749)

* Fix #21748: TileElement out of bounds

This fixes crashes observed and allows the park to load. The park is
overlarge and breaks some assumptions we have in our code.

* Use ternaries for checking conditions
---
 distribution/changelog.txt          | 1 +
 src/openrct2/world/Map.cpp          | 6 +++---
 src/openrct2/world/MapAnimation.cpp | 4 ++++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/distribution/changelog.txt b/distribution/changelog.txt
index b0fb37a7d6..ea327ed55e 100644
--- a/distribution/changelog.txt
+++ b/distribution/changelog.txt
@@ -12,6 +12,7 @@
 - Fix: [#18723, #21870] Attempting to demolish a flat ride in pause mode allows you to place multiple copies.
 - Fix: [#19559] Custom rides with long descriptions extend into lower widgets.
 - Fix: [#21696] Fullscreen window option not correctly applied on macOS.
+- Fix: [#21749] Crash when loading park bigger than current limits.
 - Fix: [#21787] Map generator heightmap should respect increased height limits.
 - Fix: [#21829] When creating a new scenario, the default name contains formatting codes.
 - Fix: [#21937] Build errors with the ORIGINAL_RATINGS flag.
diff --git a/src/openrct2/world/Map.cpp b/src/openrct2/world/Map.cpp
index 4c28730c5a..bca8e1bf62 100644
--- a/src/openrct2/world/Map.cpp
+++ b/src/openrct2/world/Map.cpp
@@ -300,7 +300,7 @@ int32_t TileElementIteratorNext(TileElementIterator* it)
     if (it->element == nullptr)
     {
         it->element = MapGetFirstElementAt(TileCoordsXY{ it->x, it->y });
-        return 1;
+        return it->element == nullptr ? 0 : 1;
     }
 
     if (!it->element->IsLastForTile())
@@ -314,7 +314,7 @@ int32_t TileElementIteratorNext(TileElementIterator* it)
     {
         it->y++;
         it->element = MapGetFirstElementAt(TileCoordsXY{ it->x, it->y });
-        return 1;
+        return it->element == nullptr ? 0 : 1;
     }
 
     if (it->x < (gameState.MapSize.x - 2))
@@ -322,7 +322,7 @@ int32_t TileElementIteratorNext(TileElementIterator* it)
         it->y = 1;
         it->x++;
         it->element = MapGetFirstElementAt(TileCoordsXY{ it->x, it->y });
-        return 1;
+        return it->element == nullptr ? 0 : 1;
     }
 
     return 0;
diff --git a/src/openrct2/world/MapAnimation.cpp b/src/openrct2/world/MapAnimation.cpp
index f582b0eda4..9c1751d48b 100644
--- a/src/openrct2/world/MapAnimation.cpp
+++ b/src/openrct2/world/MapAnimation.cpp
@@ -619,6 +619,10 @@ void MapAnimationAutoCreate()
 
 void MapAnimationAutoCreateAtTileElement(TileCoordsXY coords, TileElement* el)
 {
+    if (el == nullptr)
+    {
+        return;
+    }
     auto loc = CoordsXYZ{ coords.ToCoordsXY(), el->GetBaseZ() };
     switch (el->GetType())
     {