Do not skip sequence attribute on decode error

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2096](https://github.com/open-telemetry/opentelemetry-python/pull/2096))
 - Fix propagation bug caused by counting skipped entries
   ([#2071](https://github.com/open-telemetry/opentelemetry-python/pull/2071))
+- Do not skip sequence attribute on decode error
+  ([#2097](https://github.com/open-telemetry/opentelemetry-python/pull/2097))
 
 ## [1.5.0-0.24b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.5.0-0.24b0) - 2021-08-26
 

opentelemetry-api/src/opentelemetry/attributes/__init__.py

@@ -59,13 +59,9 @@ def _clean_attribute(
         cleaned_seq = []
 
         for element in value:
-            # None is considered valid in any sequence
-            if element is None:
-                cleaned_seq.append(element)
-
             element = _clean_attribute_value(element, max_len)
-            # reject invalid elements
             if element is None:
+                cleaned_seq.append(element)
                 continue
 
             element_type = type(element)

opentelemetry-api/tests/attributes/test_attributes.py

@@ -69,6 +69,25 @@ def test_clean_attribute(self):
         self.assertInvalid("value", "")
         self.assertInvalid("value", None)
 
+    def test_sequence_attr_decode(self):
+        seq = [
+            None,
+            b"Content-Disposition",
+            b"Content-Type",
+            b"\x81",
+            b"Keep-Alive",
+        ]
+        expected = [
+            None,
+            "Content-Disposition",
+            "Content-Type",
+            None,
+            "Keep-Alive",
+        ]
+        self.assertEqual(
+            _clean_attribute("headers", seq, None), tuple(expected)
+        )
+
 
 class TestBoundedAttributes(unittest.TestCase):
     base = collections.OrderedDict(