From c324f1ce8285f1bd629b37bca71153ad8607f7e9 Mon Sep 17 00:00:00 2001
From: Christian Speckner <christian.speckner@mayflower.de>
Date: Thu, 19 Dec 2019 18:12:20 +0100
Subject: [PATCH] Safety belt.

---
 src/emucore/tia/frame-manager/FrameManager.cxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/emucore/tia/frame-manager/FrameManager.cxx b/src/emucore/tia/frame-manager/FrameManager.cxx
index 34179d864..cc3b9fafe 100644
--- a/src/emucore/tia/frame-manager/FrameManager.cxx
+++ b/src/emucore/tia/frame-manager/FrameManager.cxx
@@ -127,6 +127,8 @@ Int32 FrameManager::missingScanlines() const
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void FrameManager::setVcenter(Int32 vcenter)
 {
+  if (vcenter < TIAConstants::minVcenter || vcenter > TIAConstants::maxVcenter) return;
+
   myVcenter = vcenter;
   updateYStart();
 }