From 5b4d28f710b28fe05639825cc98d80b209b46a47 Mon Sep 17 00:00:00 2001
From: Terry Moore <tmm@mcci.com>
Date: Mon, 30 Dec 2019 11:48:27 -0500
Subject: [PATCH] Fix #510: correct macCmd validity check

---
 src/lmic/lmic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lmic/lmic.c b/src/lmic/lmic.c
index 3fcb4e84..3dce9c07 100644
--- a/src/lmic/lmic.c
+++ b/src/lmic/lmic.c
@@ -721,7 +721,7 @@ static CONST_TABLE(u1_t, macCmdSize)[] = {
 static u1_t getMacCmdSize(u1_t macCmd) {
     if (macCmd < 2)
         return 0;
-    if (macCmd >= LENOF_TABLE(macCmdSize) - 2)
+    if ((macCmd - 2) >= LENOF_TABLE(macCmdSize))
         return 0;
     return TABLE_GET_U1(macCmdSize, macCmd - 2);
 }