rcode0-driver: add regressiontest for #2042

Author: MikeAT

libcloud/test/dns/fixtures/rcodezero/list_records.json

@@ -26,6 +26,17 @@
                     "disabled": false
                 }
             ]
+        },
+        {
+            "name": "aaaaexisting.example.at.",
+            "type": "AAAA",
+            "ttl": 3600,
+            "records": [
+                {
+                    "content": "2001:db8::42",
+                    "disabled": false
+                }
+            ]
         }
     ],
     "from": 1,

libcloud/test/dns/test_rcodezero.py

@@ -89,7 +89,7 @@ def test_list_record_types(self):
 
     def test_list_records(self):
         records = self.driver.list_records(self.test_zone)
-        self.assertEqual(len(records), 3)
+        self.assertEqual(len(records), 4)
 
     def test_list_zones(self):
         zones = self.driver.list_zones()
@@ -118,6 +118,24 @@ def test_update_record(self):
         self.assertEqual(record.type, RecordType.A)
         self.assertEqual(record.ttl, 300)
 
+    # test issue #2042
+    def test_add_other_type_to_existing_record(self):
+        payload = self.driver._to_patchrequest(
+            self.test_record.zone.id,
+            self.test_record,
+            "aaaaexisting",
+            RecordType.A,
+            "127.0.0.1",
+            {"ttl": 300},
+            "update",
+        )
+        self.assertEqual(payload[0]["name"], "aaaaexisting.example.at.")
+        self.assertEqual(payload[0]["type"], RecordType.A)
+        self.assertEqual(payload[0]["ttl"], 300)
+        self.assertEqual(payload[0]["changetype"], "update")
+        expected_record = [{"content": "127.0.0.1"}]
+        self.assertEqual(payload[0]["records"], expected_record)
+
     def test_update_zone(self):
         with self.assertRaises(NotImplementedError):
             self.driver.update_zone(self.test_zone, "example.at")