From 51b39b68b7ac3f46e75806026ab44b69cf6281ac Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Thu, 3 Nov 2022 19:54:53 +0000
Subject: [PATCH] VarAction2: Fix technical undefined behaviour advancing
 iterator

Fixes error when using debug mode containers
---
 src/newgrf_optimiser.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/newgrf_optimiser.cpp b/src/newgrf_optimiser.cpp
index 3b67d5cd77..9424640b02 100644
--- a/src/newgrf_optimiser.cpp
+++ b/src/newgrf_optimiser.cpp
@@ -2336,7 +2336,7 @@ static void OptimiseVarAction2DeterministicSpriteGroupInsertJumps(DeterministicS
 						i--;
 					}
 				}
-				group->adjusts.insert(group->adjusts.begin() + j + 1, current);
+				group->adjusts.insert(group->adjusts.begin() + (j + 1), current);
 				group->dsg_flags |= DSGF_CHECK_INSERT_JUMP;
 				i++;
 			}