If either or both of the parameters passed to ASN1_TYPE_cmp() is NULL the
return value is nonzero. Technically if both parameters are NULL the two
-types could be absent OPTIONAL fields and so should match, however passing
+types could be absent OPTIONAL fields and so should match, however, passing
NULL values could also indicate a programming error (for example an
unparsable type which returns NULL) for types which do B<not> match. So
applications should handle the case of two absent values separately.