fix for 3940.17.12

when the newly created object has the signature __attrs_attrs__ attribute
initialisation is not done using update by by calling __init__()

1 files changed, 4 insertions, 1 deletions

diff --git a/constructor.py b/constructor.py
index 3cc76a3..1673479 100644
--- a/constructor.py
+++ b/constructor.py
@@ -1635,7 +1635,10 @@ class RoundTripConstructor(SafeConstructor):
             data.__setstate__(state)
         else:
             state = SafeConstructor.construct_mapping(self, node)
-            data.__dict__.update(state)
+            if hasattr(data, '__attrs_attrs__'):  # issue 394
+                cls.__init__(cls, **state)
+            else:
+                data.__dict__.update(state)
         if node.anchor:
             from ruamel.yaml.serializer import templated_id
             from ruamel.yaml.anchor import Anchor