From 31fe9979dd4b5c604f3acb69ba5d84ecdf3da92b Mon Sep 17 00:00:00 2001
From: refractionpcsx2 <refraction@gmail.com>
Date: Fri, 15 Apr 2022 19:17:36 +0100
Subject: [PATCH] GS: Fix undefined behaviour on interlacing

---
 pcsx2/GS/Renderers/Common/GSRenderer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pcsx2/GS/Renderers/Common/GSRenderer.cpp b/pcsx2/GS/Renderers/Common/GSRenderer.cpp
index 82a5396f63..6d21a376f2 100644
--- a/pcsx2/GS/Renderers/Common/GSRenderer.cpp
+++ b/pcsx2/GS/Renderers/Common/GSRenderer.cpp
@@ -402,7 +402,7 @@ bool GSRenderer::Merge(int field)
 			}
 			else
 			{
-				const int field2 = scanmask ? 0 : 0 - ((static_cast<int>(GSConfig.InterlaceMode) - 1) & 1);
+				const int field2 = scanmask ? 0 : 1 - ((static_cast<int>(GSConfig.InterlaceMode) - 1) & 1);
 				const int offset = tex[1] ? tex[1]->GetScale().y : tex[0]->GetScale().y;
 				const int mode = scanmask ? 2 : ((static_cast<int>(GSConfig.InterlaceMode) - 1) >> 1);