From 6d759283877e30f5e680c25765ebe35c4e408cb2 Mon Sep 17 00:00:00 2001
From: Benjamin Wohlwend <beni@elastic.co>
Date: Wed, 30 Mar 2022 13:50:41 +0200
Subject: [PATCH 1/2] fix issue in span serialization when using APM Server <
 7.16

the issue wasn't originally caught in testing because we hardcode
the server_version to a certain value (currently 8.0.0), and this
bug was in a branch that only is hit with a server version lower
than 7.16

fixes #1509
---
 elasticapm/traces.py              |  2 +-
 tests/client/transaction_tests.py | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/elasticapm/traces.py b/elasticapm/traces.py
index 8d4df7dbc..815b9527d 100644
--- a/elasticapm/traces.py
+++ b/elasticapm/traces.py
@@ -577,7 +577,7 @@ def to_dict(self) -> dict:
                         result["otel"]["attributes"] = self.context.pop("otel_attributes")
             else:
                 # Attributes map to labels for older versions
-                attributes = self.context.pop("otel_attributes")
+                attributes = self.context.pop("otel_attributes", {})
                 if attributes and ("tags" not in self.context):
                     self.context["tags"] = {}
                 for key, value in attributes.items():
diff --git a/tests/client/transaction_tests.py b/tests/client/transaction_tests.py
index 6ee0a7dce..1c7db2ede 100644
--- a/tests/client/transaction_tests.py
+++ b/tests/client/transaction_tests.py
@@ -38,6 +38,23 @@
 from elasticapm.utils.disttracing import TraceParent
 
 
+@pytest.mark.parametrize("elasticapm_client", [{"server_version": (7, 15)}, {"server_version": (7, 16)}], indirect=True)
+def test_transaction_span(elasticapm_client):
+    elasticapm_client.begin_transaction("test")
+    with elasticapm.capture_span("test", extra={"a": "b"}):
+        pass
+    elasticapm_client.end_transaction("test", constants.OUTCOME.SUCCESS)
+    transactions = elasticapm_client.events[constants.TRANSACTION]
+    assert len(transactions) == 1
+    assert transactions[0]["name"] == "test"
+    assert transactions[0]["type"] == "test"
+    assert transactions[0]["result"] == constants.OUTCOME.SUCCESS
+
+    spans = elasticapm_client.events[constants.SPAN]
+    assert len(spans) == 1
+    assert spans[0]["name"] == "test"
+
+
 @pytest.mark.parametrize(
     "elasticapm_client", [{"transactions_ignore_patterns": ["^OPTIONS", "views.api.v2"]}], indirect=True
 )

From 3c0cb4d157e4015e2941e186e3970ee334585c2d Mon Sep 17 00:00:00 2001
From: Colton Myers <colton.myers@gmail.com>
Date: Wed, 30 Mar 2022 07:57:36 -0600
Subject: [PATCH 2/2] CHANGELOG

---
 CHANGELOG.asciidoc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index 85cf3af45..462fd2e4f 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -29,6 +29,19 @@ endif::[]
 //===== Bug fixes
 //
 
+
+=== Unreleased
+
+// Unreleased changes go here
+// When the next release happens, nest these changes under the "Python Agent version 6.x" heading
+//[float]
+//===== Features
+//
+[float]
+===== Bug fixes
+
+* Fix `otel_attributes`-related regression with older versions of APM Server (<7.16) {pull}1510[#1510]
+
 [[release-notes-6.x]]
 === Python Agent version 6.x