From 1ae97818fd90c4c734bb754a81415f3832049657 Mon Sep 17 00:00:00 2001
From: Bruce Bujon <bruce.bujon@datadoghq.com>
Date: Mon, 6 Nov 2023 16:08:57 +0100
Subject: [PATCH] fix(core): Fix terminated context addition in span builder

---
 .../java/datadog/trace/core/CoreTracer.java   | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java b/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java
index dae7c75cfce..684b3794ba0 100644
--- a/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java
+++ b/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java
@@ -1191,13 +1191,7 @@ public CoreSpanBuilder ignoreActiveSpan() {
     }
 
     private DDSpan buildSpan() {
-      if (parent instanceof TagContext) {
-        List<AgentSpanLink> terminatedContextLinks =
-            ((TagContext) parent).getTerminatedContextLinks();
-        if (!terminatedContextLinks.isEmpty()) {
-          links.addAll(terminatedContextLinks);
-        }
-      }
+      addTerminatedContextAsLinks();
       DDSpan span = DDSpan.create(instrumentationName, timestampMicro, buildSpanContext(), links);
       if (span.isLocalRootSpan()) {
         EndpointTracker tracker = tracer.onRootSpanStarted(span);
@@ -1206,6 +1200,19 @@ private DDSpan buildSpan() {
       return span;
     }
 
+    private void addTerminatedContextAsLinks() {
+      if (this.parent instanceof TagContext) {
+        List<AgentSpanLink> terminatedContextLinks =
+            ((TagContext) this.parent).getTerminatedContextLinks();
+        if (!terminatedContextLinks.isEmpty()) {
+          if (this.links == null) {
+            this.links = new ArrayList<>();
+          }
+          this.links.addAll(terminatedContextLinks);
+        }
+      }
+    }
+
     @Override
     public AgentSpan start() {
       return buildSpan();