From e9c480c66edfdde773cc06b8c957ce23739ef6ed Mon Sep 17 00:00:00 2001
From: Matthias Moninger <5415177+ZehMatt@users.noreply.github.com>
Date: Wed, 3 May 2023 22:15:02 +0300
Subject: [PATCH] Fix #20121: Guard against nullptr on viewport scroll (#20122)

---
 src/openrct2-ui/input/MouseInput.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/openrct2-ui/input/MouseInput.cpp b/src/openrct2-ui/input/MouseInput.cpp
index b36c1307c6..7fbfc8a902 100644
--- a/src/openrct2-ui/input/MouseInput.cpp
+++ b/src/openrct2-ui/input/MouseInput.cpp
@@ -1646,7 +1646,12 @@ bool InputTestPlaceObjectModifier(PLACE_OBJECT_MODIFIER modifier)
 void InputScrollViewport(const ScreenCoordsXY& scrollScreenCoords)
 {
     WindowBase* mainWindow = WindowGetMain();
+    if (mainWindow == nullptr)
+        return;
+
     Viewport* viewport = mainWindow->viewport;
+    if (viewport == nullptr)
+        return;
 
     const int32_t speed = gConfigGeneral.EdgeScrollingSpeed;