From c96f2e4e3a36629ef78187f00fae10c46a7a849f Mon Sep 17 00:00:00 2001
From: Max Prokhorov <prokhorov.max@outlook.com>
Date: Mon, 18 Nov 2019 03:28:24 +0300
Subject: [PATCH] Fix strtoul error condition (#1995)

endptr is set to '\0' when successful
---
 code/espurna/utils.ino | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/espurna/utils.ino b/code/espurna/utils.ino
index d710f42b..a0c35b9c 100644
--- a/code/espurna/utils.ino
+++ b/code/espurna/utils.ino
@@ -195,7 +195,7 @@ namespace Heartbeat {
         // invalidate the whole string when invalid chars are detected
         char *value_endptr = nullptr;
         const auto value = strtoul(cfg.c_str(), &value_endptr, 10);
-        if (value_endptr) {
+        if (value_endptr == cfg.c_str() || value_endptr[0] != '\0') {
             return defaultValue();
         }