From 2f09eff40434ad48d3110faf95182f0525f4093f Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Thu, 26 May 2022 00:12:54 +0100
Subject: [PATCH] VarAction2: Convert boolean, invert sequence to ternary

---
 src/newgrf.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 3f55c8be4d..253d1dc0cc 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -5800,6 +5800,14 @@ static void NewSpriteGroup(ByteReader *buf)
 											inference = VA2AIF_SIGNED_NON_NEGATIVE | VA2AIF_ONE_OR_ZERO;
 											break;
 										}
+										if (prev.operation == DSGA_OP_UMIN && prev.type == DSGA_TYPE_NONE && prev.variable == 0x1A && prev.shift_num == 0 && prev.and_mask == 1) {
+											prev.operation = DSGA_OP_TERNARY;
+											prev.and_mask = 0;
+											prev.add_val = 1;
+											group->adjusts.pop_back();
+											inference = VA2AIF_PREV_TERNARY;
+											break;
+										}
 									}
 									if (adjust.and_mask <= 1) inference = prev_inference & (VA2AIF_SIGNED_NON_NEGATIVE | VA2AIF_ONE_OR_ZERO);
 									break;