From 609f37cef953b2e95ed21216eaa51928aa688d1e Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Fri, 2 Oct 2020 17:50:20 +0100
Subject: [PATCH] Fix OverflowSafeInt negation not handling INT64_MIN

See: https://github.com/OpenTTD/OpenTTD/issues/8284
---
 src/core/overflowsafe_type.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/overflowsafe_type.hpp b/src/core/overflowsafe_type.hpp
index 25fa715572..19cfd2bfb5 100644
--- a/src/core/overflowsafe_type.hpp
+++ b/src/core/overflowsafe_type.hpp
@@ -36,7 +36,7 @@ public:
 
 	inline OverflowSafeInt& operator = (const OverflowSafeInt& other) { this->m_value = other.m_value; return *this; }
 
-	inline OverflowSafeInt operator - () const { return OverflowSafeInt(-this->m_value); }
+	inline OverflowSafeInt operator - () const { return OverflowSafeInt(this->m_value == T_MIN ? T_MAX : -this->m_value); }
 
 	/**
 	 * Safe implementation of addition.