Correct status transform in OTLP exporter (#2102)

* Correct status transform in OTLP exporter

* Add changes to changelog

CHANGELOG.md

@@ -29,6 +29,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - When using WithNewRoot, don't use the parent context for making sampling decisions. (#2032)
 - `oteltest.Tracer` now creates a valid `SpanContext` when using `WithNewRoot`. (#2073)
 - OS type detector now sets the correct `dragonflybsd` value for DragonFly BSD. (#2092)
+- The OTel span status is correctly transformed into the OTLP status in the `go.opentelemetry.io/otel/exporters/otlp/otlptrace` package.
+  This fix will by default set the status to `Unset` if it is not explicitly set to `Ok` or `Error`. (#2099 #2102)
 
 ### Security
 

exporters/otlp/otlptrace/internal/tracetransform/span.go

@@ -132,10 +132,12 @@ func span(sd tracesdk.ReadOnlySpan) *tracepb.Span {
 func status(status codes.Code, message string) *tracepb.Status {
 	var c tracepb.Status_StatusCode
 	switch status {
+	case codes.Ok:
+		c = tracepb.Status_STATUS_CODE_OK
 	case codes.Error:
 		c = tracepb.Status_STATUS_CODE_ERROR
 	default:
-		c = tracepb.Status_STATUS_CODE_OK
+		c = tracepb.Status_STATUS_CODE_UNSET
 	}
 	return &tracepb.Status{
 		Code:    c,

exporters/otlp/otlptrace/internal/tracetransform/span_test.go

@@ -169,7 +169,11 @@ func TestStatus(t *testing.T) {
 		{
 			codes.Unset,
 			"test Unset",
-			tracepb.Status_STATUS_CODE_OK,
+			tracepb.Status_STATUS_CODE_UNSET,
+		},
+		{
+			message:    "default code is unset",
+			otlpStatus: tracepb.Status_STATUS_CODE_UNSET,
 		},
 		{
 			codes.Error,