idna_decode barfs on .., so needs a work-around

octodns/idna.py

@@ -45,7 +45,10 @@ def idna_decode(name):
             if name.startswith('*'):
                 # idna.decode doesn't like the *
                 return f'*.{_decode(name[2:])}'
-            return _decode(name)
+            # idna.decode doesn't like .. so we stick a unique placeholder
+            # anywhere we see it and then remove it again afterwards.
+            name = name.replace('..', '.pl-a-ce--hold-e--r.')
+            return _decode(name).replace('.pl-a-ce--hold-e--r.', '..')
         except _IDNAError as e:
             raise IdnaError(e)
     # not idna, just return as-is

tests/test_octodns_idna.py

@@ -66,8 +66,10 @@ class TestIdna(TestCase):
         self.assertEqual('Empty Label', str(ctx.exception))
 
         with self.assertRaises(IdnaError) as ctx:
-            idna_decode('xn--djvu-1na6c..com.')
-        self.assertEqual('Empty Label', str(ctx.exception))
+            idna_decode('xn--djvu-1na6c.something-.com.')
+        self.assertEqual(
+            'Label must not start or end with a hyphen', str(ctx.exception)
+        )
 
 
 class TestIdnaDict(TestCase):

tests/test_octodns_record.py

@@ -692,6 +692,18 @@ class TestRecordValidation(TestCase):
             reason,
         )
 
+        # double dots in idna names
+        with self.assertRaises(ValidationError) as ctx:
+            Record.new(
+                self.zone,
+                'niño.',
+                {'ttl': 301, 'type': 'A', 'value': '1.2.3.4'},
+            )
+        reason = ctx.exception.reasons[0]
+        self.assertEqual(
+            'invalid name, double `.` in "niño..unit.tests."', reason
+        )
+
         # no ttl
         with self.assertRaises(ValidationError) as ctx:
             Record.new(self.zone, '', {'type': 'A', 'value': '1.2.3.4'})