From 89feacb813f3791ff7cd74498b2b568aa7b7e4ba Mon Sep 17 00:00:00 2001
From: Artur Bieniek <ar2rekb@gmail.com>
Date: Wed, 5 Jun 2019 13:48:13 +0200
Subject: [PATCH] Fix map() division by zero (#2848)

---
 cores/esp32/WMath.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/cores/esp32/WMath.cpp b/cores/esp32/WMath.cpp
index 891a737d..abec110b 100644
--- a/cores/esp32/WMath.cpp
+++ b/cores/esp32/WMath.cpp
@@ -65,9 +65,12 @@ long random(long howsmall, long howbig)
     return random(diff) + howsmall;
 }
 
-long map(long x, long in_min, long in_max, long out_min, long out_max)
-{
-    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+long map(long x, long in_min, long in_max, long out_min, long out_max) {
+    long divisor = (in_max - in_min);
+    if(divisor == 0){
+        return -1; //AVR returns -1, SAM returns 0
+    }
+    return (x - in_min) * (out_max - out_min) / divisor + out_min;
 }
 
 unsigned int makeWord(unsigned int w)