diff --git a/core/postmultiparser.cpp b/core/postmultiparser.cpp
index 0772c50..db115c9 100755
--- a/core/postmultiparser.cpp
+++ b/core/postmultiparser.cpp
@@ -238,16 +238,24 @@ size_t i;
 
 void PostMultiParser::ReadContentSkipBoundary(bool has_boundary)
 {
-	if( has_boundary )
+	if( has_boundary && content.size() >= boundary.size() )
+	{
 		content.erase(content.size()-boundary.size());
+		content_len -= boundary.size();
+	}
 
 	// the last new line character doesn't belong to the content
+	// this is a new line character before the boundary
 	if( !content.empty() && content[content.size()-1] == 10 )
 	{
 		content.erase(content.size()-1);
+		content_len -= 1;
 
 		if( line_end_dos && !content.empty() && content[content.size()-1] == 13 )
+		{
 			content.erase(content.size()-1);
+			content_len -= 1;
+		}
 	}
 }
 
@@ -260,12 +268,12 @@ bool has_boundary = false;
 	while( last!=-1 && !(has_boundary=HasBoundary()) )
 	{
 		content += last;
+		content_len += 1;
 		ReadChar();
 
 		if( content.size() > WINIX_POSTMULTI_OUTPUT_BUFFER + boundary.size() + 2 ) // +2 for the new line character
 		{
 			tmp_file.write(content.c_str(), WINIX_POSTMULTI_OUTPUT_BUFFER);
-			content_len += WINIX_POSTMULTI_OUTPUT_BUFFER;
 			content.erase(0, WINIX_POSTMULTI_OUTPUT_BUFFER);
 		}
 
@@ -283,7 +291,6 @@ bool has_boundary = false;
 	if( !content.empty() )
 	{
 		tmp_file.write(content.c_str(), content.size());
-		content_len += content.size();
 		content.clear();
 	}
 }