Detect division by zero.

slav-at-attachix · slav-at-attachix · commit b77d6bd21a75 · 2017-06-01T13:39:41.000+02:00
See esp8266/Arduino#2397 for details.
diff --git a/Sming/Wiring/WMath.cpp b/Sming/Wiring/WMath.cpp
@@ -79,9 +79,12 @@ long random(long howsmall, long howbig)
 }
 
 
-long map(long x, long in_min, long in_max, long out_min, long out_max)
-{
-  return (x - in_min) * (out_max - out_min + 1) / (in_max - in_min + 1) + out_min;
+long map(long x, long in_min, long in_max, long out_min, long out_max) {
+    long divisor = (in_max - in_min) + out_min;
+    if(divisor == 0){
+        return -1; //AVR returns -1, SAM returns 0
+    }
+    return (x - in_min) * (out_max - out_min) / divisor;
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -79,9 +79,12 @@ long random(long howsmall, long howbig)`
`79`	`79`	`}`
`80`	`80`
`81`	`81`
`82`		`-long map(long x, long in_min, long in_max, long out_min, long out_max)`
`83`		`-{`
`84`		`- return (x - in_min) * (out_max - out_min + 1) / (in_max - in_min + 1) + out_min;`
	`82`	`+long map(long x, long in_min, long in_max, long out_min, long out_max) {`
	`83`	`+ long divisor = (in_max - in_min) + out_min;`
	`84`	`+ if(divisor == 0){`
	`85`	`+ return -1; //AVR returns -1, SAM returns 0`
	`86`	`+ }`
	`87`	`+ return (x - in_min) * (out_max - out_min) / divisor;`
`85`	`88`	`}`
`86`	`89`
`87`	`90`