add test empty domain in to bytes in nsec (fails for a bug)

Author: konegoro

src/message/rdata/nsec_rdata.rs

@@ -477,5 +477,28 @@ mod nsec_rdata_test{
         assert_eq!(nsec_rdata.to_bytes(), bytes_to_test);
     }
 
+    #[test]
+    fn from_bytes_empty_domain() {
+        let next_domain_name_bytes = vec![0, 0]; //codification for domain name = ""
+
+        let bit_map_bytes_to_test = vec![0, 6, 64, 1, 0, 0, 0, 3, 
+                                    4, 27, 0, 0, 0, 0, 0, 0, 0,
+                                    0, 0, 0, 0, 0, 0, 0, 0, 0, 
+                                    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32];
+
+        let bytes_to_test = [next_domain_name_bytes, bit_map_bytes_to_test].concat();
+
+        //FIXME: If the domain name in bytes is the "", then from_bytes reads the 64 like the map lenght instead of 6
+        // this must because are two zeros in the domain, and after read the first zero, the other (the second) became part of the bitmap
+        let nsec_rdata = NsecRdata::from_bytes(&bytes_to_test, &bytes_to_test).unwrap();
+
+        let expected_next_domain_name = String::from("");
+
+        assert_eq!(nsec_rdata.get_next_domain_name().get_name(), expected_next_domain_name);
+
+        let expected_type_bit_maps = vec![Rtype::A, Rtype::MX, Rtype::RRSIG, Rtype::NSEC, Rtype::UNKNOWN(1234)];
+
+        assert_eq!(nsec_rdata.get_type_bit_maps(), expected_type_bit_maps);
+    }
 
 }