From dadbeff43375e586e42f614b548d4d2b5288b48e Mon Sep 17 00:00:00 2001
From: Sean Parkinson <sean@wolfssl.com>
Date: Tue, 26 Nov 2019 09:55:17 +1000
Subject: [PATCH] sp_int: When setting digit of 0, set used to 0

---
 wolfcrypt/src/sp_int.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index 137f75f16..1acda20a3 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -420,8 +420,14 @@ int sp_init_copy (sp_int * a, sp_int * b)
  */
 int sp_set(sp_int* a, sp_int_digit d)
 {
-    a->dp[0] = d;
-    a->used = 1;
+    if (d == 0) {
+      a->dp[0] = d;
+      a->used = 0;
+    }
+    else {
+      a->dp[0] = d;
+      a->used = 1;
+    }
     return MP_OKAY;
 }