From 5c9d10ad9484c26eb94d2030628b676f8d0d5fc7 Mon Sep 17 00:00:00 2001
From: "David A. Mellis" <d.mellis@arduino.cc>
Date: Tue, 25 Oct 2011 11:15:14 -0400
Subject: [PATCH] Bug fix in replace().

http://code.google.com/p/arduino/issues/detail?id=694
---
 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 ad8d828..3e81331 100644
--- a/cores/arduino/WString.cpp
+++ b/cores/arduino/WString.cpp
@@ -593,7 +593,7 @@ void String::replace(const String& find, const String& replace)
 		if (size == len) return;
 		if (size > capacity && !changeBuffer(size)) return; // XXX: tell user!
 		int index = len - 1;
-		while ((index = lastIndexOf(find, index)) >= 0) {
+		while (index >= 0 && (index = lastIndexOf(find, index)) >= 0) {
 			readFrom = buffer + index + find.len;
 			memmove(readFrom + diff, readFrom, len - (readFrom - buffer));
 			len += diff;