From 5d61d8ddd004e83fec3d5cabca46c1990fee7b13 Mon Sep 17 00:00:00 2001
From: me-no-dev <hristo@espressif.com>
Date: Tue, 11 Oct 2016 11:42:47 +0300
Subject: [PATCH] copy va_list in Print::printf

---
 cores/esp32/Print.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cores/esp32/Print.cpp b/cores/esp32/Print.cpp
index d758478b..5afa9ded 100644
--- a/cores/esp32/Print.cpp
+++ b/cores/esp32/Print.cpp
@@ -49,9 +49,12 @@ size_t Print::printf(const char *format, ...)
     char loc_buf[64];
     char * temp = loc_buf;
     va_list arg;
+    va_list copy;
     va_start(arg, format);
+    va_copy(copy, arg);
     size_t len = vsnprintf(NULL, 0, format, arg);
-    if(len > 64){
+    va_end(copy);
+    if(len >= sizeof(loc_buf)){
         temp = new char[len+1];
         if(temp == NULL) {
             return 0;