From 27f70a335008ed7cdb398013eedf6812cc1c44e0 Mon Sep 17 00:00:00 2001
From: CZ <cz@mx51.io>
Date: Fri, 29 Dec 2023 06:46:17 +1300
Subject: [PATCH] bridge/opentracing: fix baggage item key is canonicalized
 (#4776)
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Co-authored-by: Robert Pająk <pellared@hotmail.com>
Co-authored-by: Yuri Shkuro <yurishkuro@users.noreply.github.com>
---
 CHANGELOG.md                      |  1 +
 bridge/opentracing/bridge.go      |  7 +--
 bridge/opentracing/bridge_test.go | 84 +++++++++++++++++++++++++++++++
 bridge/opentracing/mix_test.go    |  4 +-
 4 files changed, 89 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b94281d2ff5..717a990bc7a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,6 +35,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - Fix `Parse` in `go.opentelemetry.io/otel/baggage` to validate member value before percent-decoding. (#4755)
 - Fix whitespace encoding of `Member.String` in `go.opentelemetry.io/otel/baggage`. (#4756)
+- Fix baggage item key so that it is not canonicalized in `go.opentelemetry.io/otel/bridge/opentracing`. (#4776)
 
 ## [1.21.0/0.44.0] 2023-11-16
 
diff --git a/bridge/opentracing/bridge.go b/bridge/opentracing/bridge.go
index cc3d7d19c7f..f61dc9eee00 100644
--- a/bridge/opentracing/bridge.go
+++ b/bridge/opentracing/bridge.go
@@ -17,7 +17,6 @@ package opentracing // import "go.opentelemetry.io/otel/bridge/opentracing"
 import (
 	"context"
 	"fmt"
-	"net/http"
 	"strings"
 	"sync"
 
@@ -74,8 +73,7 @@ func (c *bridgeSpanContext) ForeachBaggageItem(handler func(k, v string) bool) {
 }
 
 func (c *bridgeSpanContext) setBaggageItem(restrictedKey, value string) {
-	crk := http.CanonicalHeaderKey(restrictedKey)
-	m, err := baggage.NewMember(crk, value)
+	m, err := baggage.NewMember(restrictedKey, value)
 	if err != nil {
 		return
 	}
@@ -83,8 +81,7 @@ func (c *bridgeSpanContext) setBaggageItem(restrictedKey, value string) {
 }
 
 func (c *bridgeSpanContext) baggageItem(restrictedKey string) baggage.Member {
-	crk := http.CanonicalHeaderKey(restrictedKey)
-	return c.bag.Member(crk)
+	return c.bag.Member(restrictedKey)
 }
 
 type bridgeSpan struct {
diff --git a/bridge/opentracing/bridge_test.go b/bridge/opentracing/bridge_test.go
index bbeb3f9fbfe..7a3e384424b 100644
--- a/bridge/opentracing/bridge_test.go
+++ b/bridge/opentracing/bridge_test.go
@@ -574,3 +574,87 @@ func TestBridgeSpanContextPromotedMethods(t *testing.T) {
 		assert.True(t, spanContext.(spanContextProvider).HasTraceID())
 	})
 }
+
+func TestBridgeCarrierBaggagePropagation(t *testing.T) {
+	carriers := []struct {
+		name    string
+		carrier interface{}
+		format  ot.BuiltinFormat
+	}{
+		{
+			name:    "TextMapCarrier",
+			carrier: ot.TextMapCarrier{},
+			format:  ot.TextMap,
+		},
+		{
+			name:    "HTTPHeadersCarrier",
+			carrier: ot.HTTPHeadersCarrier{},
+			format:  ot.HTTPHeaders,
+		},
+	}
+
+	testCases := []struct {
+		name         string
+		baggageItems []bipBaggage
+	}{
+		{
+			name: "single baggage item",
+			baggageItems: []bipBaggage{
+				{
+					key:   "foo",
+					value: "bar",
+				},
+			},
+		},
+		{
+			name: "multiple baggage items",
+			baggageItems: []bipBaggage{
+				{
+					key:   "foo",
+					value: "bar",
+				},
+				{
+					key:   "foo2",
+					value: "bar2",
+				},
+			},
+		},
+	}
+
+	for _, c := range carriers {
+		for _, tc := range testCases {
+			t.Run(fmt.Sprintf("%s %s", c.name, tc.name), func(t *testing.T) {
+				mockOtelTracer := internal.NewMockTracer()
+				b, _ := NewTracerPair(mockOtelTracer)
+				b.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
+					propagation.TraceContext{},
+					propagation.Baggage{}), // Required for baggage propagation.
+				)
+
+				// Set baggage items.
+				span := b.StartSpan("test")
+				for _, bi := range tc.baggageItems {
+					span.SetBaggageItem(bi.key, bi.value)
+				}
+				defer span.Finish()
+
+				err := b.Inject(span.Context(), c.format, c.carrier)
+				assert.NoError(t, err)
+
+				spanContext, err := b.Extract(c.format, c.carrier)
+				assert.NoError(t, err)
+
+				// Check baggage items.
+				bsc, ok := spanContext.(*bridgeSpanContext)
+				assert.True(t, ok)
+
+				var got []bipBaggage
+				for _, m := range bsc.bag.Members() {
+					got = append(got, bipBaggage{m.Key(), m.Value()})
+				}
+
+				assert.ElementsMatch(t, tc.baggageItems, got)
+			})
+		}
+	}
+}
diff --git a/bridge/opentracing/mix_test.go b/bridge/opentracing/mix_test.go
index 0cd5a667ca5..b57f37e8ea7 100644
--- a/bridge/opentracing/mix_test.go
+++ b/bridge/opentracing/mix_test.go
@@ -334,7 +334,7 @@ func newBaggageItemsPreservationTest() *baggageItemsPreservationTest {
 				value: "two",
 			},
 			{
-				key:   "Third",
+				key:   "third",
 				value: "three",
 			},
 		},
@@ -427,7 +427,7 @@ func newBaggageInteroperationTest() *baggageInteroperationTest {
 				value: "two",
 			},
 			{
-				key:   "Third",
+				key:   "third",
 				value: "three",
 			},
 		},