From 030b2b5be81dce82589534ddbfcf1f9c530bb354 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sat, 24 Jul 2010 06:46:58 +0000
Subject: [PATCH] don't dereference empty strings

---
 include/libtorrent/utf8.hpp | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/libtorrent/utf8.hpp b/include/libtorrent/utf8.hpp
index ae8f2a59d..7587ab36e 100644
--- a/include/libtorrent/utf8.hpp
+++ b/include/libtorrent/utf8.hpp
@@ -50,15 +50,15 @@ namespace libtorrent
 	{
 		// allocate space for worst-case
 		wide.resize(utf8.size());
-		wchar_t const* dst_start = &wide[0];
-		char const* src_start = &utf8[0];
+		wchar_t const* dst_start = wide.c_str();
+		char const* src_start = utf8.c_str();
 		ConversionResult ret;
 		if (sizeof(wchar_t) == sizeof(UTF32))
 		{
 			ret = ConvertUTF8toUTF32((const UTF8**)&src_start, (const UTF8*)src_start
 				+ utf8.size(), (UTF32**)&dst_start, (UTF32*)dst_start + wide.size()
 				, lenientConversion);
-			wide.resize(dst_start - &wide[0]);
+			wide.resize(dst_start - wide.c_str());
 			return ret;
 		}
 		else if (sizeof(wchar_t) == sizeof(UTF16))
@@ -66,7 +66,7 @@ namespace libtorrent
 			ret = ConvertUTF8toUTF16((const UTF8**)&src_start, (const UTF8*)src_start
 				+ utf8.size(), (UTF16**)&dst_start, (UTF16*)dst_start + wide.size()
 				, lenientConversion);
-			wide.resize(dst_start - &wide[0]);
+			wide.resize(dst_start - wide.c_str());
 			return ret;
 		}
 		else
@@ -79,8 +79,9 @@ namespace libtorrent
 	{
 		// allocate space for worst-case
 		utf8.resize(wide.size() * 6);
+		if (wide.empty()) return 0;
 		char* dst_start = &utf8[0];
-		wchar_t const* src_start = &wide[0];
+		wchar_t const* src_start = wide.c_str();
 		ConversionResult ret;
 		if (sizeof(wchar_t) == sizeof(UTF32))
 		{