workaround std::string problem in MacOS Xc50-fixes

git-svn-id: svn://svn.code.sf.net/p/cryptopp/code/branches/c50-fixes/c5@36 57ff6487-cd31-0410-9ec3-f628ee90f5f0

1 files changed, 2 insertions, 1 deletions

diff --git a/filters.h b/filters.h
index 1b8965b..eb119b2 100644
--- a/filters.h
+++ b/filters.h
@@ -493,7 +493,8 @@ public:
 		{if (!parameters.GetValue("OutputStringPointer", m_output)) throw InvalidArgument("StringSink: OutputStringPointer not specified");}
 	unsigned int Put2(const byte *begin, unsigned int length, int messageEnd, bool blocking)
 	{
-		m_output->append((const char_type *)begin, (const char_type *)begin+length);
+		if (length > 0)
+			m_output->append((const char_type *)begin, (const char_type *)begin+length);
 		return 0;
 	}