Clear cached serializer data on `save()` + test. Fixes #1116.

1 files changed, 3 insertions, 0 deletions

diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index a63c7f6c..8d2e0feb 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -518,6 +518,9 @@ class BaseSerializer(WritableField):
         """
         Save the deserialized object and return it.
         """
+        # Clear cached _data, which may be invalidated by `save()`
+        self._data = None
+
         if isinstance(self.object, list):
             [self.save_object(item, **kwargs) for item in self.object]