From 5f288cbd43baf6e236f131a5619b8df193d5af5c Mon Sep 17 00:00:00 2001
From: thebigMuh <daniel.rind@chello.at>
Date: Sun, 18 Apr 2021 22:22:03 +0200
Subject: [PATCH] Fixes small AC malus of less than 1 resulting in a bonus of 1
 AC

---
 Source/items.cpp    |  3 ++-
 Source/utils/math.h | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 Source/utils/math.h

diff --git a/Source/items.cpp b/Source/items.cpp
index d4b4b1bd3..e62a2cf26 100644
--- a/Source/items.cpp
+++ b/Source/items.cpp
@@ -16,6 +16,7 @@
 #include "options.h"
 #include "stores.h"
 #include "utils/language.h"
+#include "utils/math.h"
 
 namespace devilution {
 
@@ -600,7 +601,7 @@ void CalcPlrItemVals(int p, bool Loadgfx)
 					tmpac *= itm->_iPLAC;
 					tmpac /= 100;
 					if (tmpac == 0)
-						tmpac = 1;
+						tmpac = math::Sign(itm->_iPLAC);
 					bac += tmpac;
 				}
 				iflgs |= itm->_iFlags;
diff --git a/Source/utils/math.h b/Source/utils/math.h
new file mode 100644
index 000000000..6cb2b97f3
--- /dev/null
+++ b/Source/utils/math.h
@@ -0,0 +1,24 @@
+/**
+* @file math.h
+*
+* Math utility functions
+*/
+#pragma once
+
+namespace devilution {
+namespace math {
+
+/**
+ * @brief Compute sign of t
+ * @tparam T Any arithmetic type
+ * @param t Value to compute sign of
+ * @return -1 if t < 0, 1 if t > 0, 0 if t == 0
+*/
+template<typename T>
+int Sign(T t)
+{
+	return (t > T(0)) - (t < T(0));
+}
+
+} // namespace math
+} // namespace devilution