Call error_handler when calling Schema#validate

fix #121

marshmallow/schema.py

@@ -488,8 +488,6 @@ def load(self, data, many=None):
         .. versionadded:: 1.0.0
         """
         result, errors = self._do_load(data, many, postprocess=True)
-        if self._unmarshal.errors and callable(self.__error_handler__):
-            self.__error_handler__(self._unmarshal.errors, data)
         return UnmarshalResult(data=result, errors=errors)
 
     def loads(self, json_data, many=None, *args, **kwargs):
@@ -598,6 +596,8 @@ def _do_load(self, data, many=None, postprocess=True):
             dict_class=self.dict_class
         )
         errors = self._unmarshal.errors
+        if errors and callable(self.__error_handler__):
+            self.__error_handler__(errors, data)
         return result, errors
 
     def _update_fields(self, obj=None, many=False):

tests/test_schema.py

@@ -775,6 +775,14 @@ def handle_errors(serializer, errors, data):
         with pytest.raises(CustomError):
             MySchema().load({'email': 'invalid'})
 
+    def test_validate_with_custom_error_handler(self):
+        @MySchema.error_handler
+        def handle_errors(schema, errors, data):
+            raise CustomError('Something bad happened')
+
+        with pytest.raises(CustomError):
+            MySchema().validate({'email': 'invalid'})
+
     def test_multiple_serializers_with_same_error_handler(self, user):
 
         @MySchema.error_handler