From 40e5a4fcee373e8ec3e666b35a3020f0d9bf31c0 Mon Sep 17 00:00:00 2001
From: Sandeep Mistry <s.mistry@arduino.cc>
Date: Tue, 12 Jul 2016 17:42:40 -0400
Subject: [PATCH] Make String::move of an invalidated String result in an
 invalidated String

---
 cores/arduino/WString.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cores/arduino/WString.cpp b/cores/arduino/WString.cpp
index e1d60f471..533298225 100644
--- a/cores/arduino/WString.cpp
+++ b/cores/arduino/WString.cpp
@@ -195,7 +195,7 @@ String & String::copy(const __FlashStringHelper *pstr, unsigned int length)
 void String::move(String &rhs)
 {
 	if (buffer) {
-		if (capacity >= rhs.len) {
+		if (rhs && capacity >= rhs.len) {
 			strcpy(buffer, rhs.buffer);
 			len = rhs.len;
 			rhs.len = 0;