filter useless (and errorfull) ASCII char for XML output

Author: Olivier Courtin

src/struct/buffer.c

@@ -502,6 +502,9 @@ buffer *buffer_encode_xml_entities_str(const char * str)
   buf = buffer_init();
 
   for( /* empty */ ; *str ; str++) {
+
+    if ((int) *str < 32 && (*str != '\n' && *str != '\r' && *str != '	')) break;
+
     switch(*str) {
       case '&':
         buffer_add_str(buf, "&amp;");