fix invalid parent index on segment reset

Author: rochdev

packages/dd-trace/src/collector/span.js

@@ -52,7 +52,7 @@ class DatadogCollectorSpan extends DatadogSpan {
 
     spanContext._spanIndex = trace.lastIndex++
 
-    if (fields.parent) {
+    if (parent && trace.segmentId === parent.segmentId) {
       spanContext._parentIndex = parent._spanIndex >= 0
         ? parent._spanIndex + 1
         : 0
@@ -98,14 +98,16 @@ class DatadogCollectorSpan extends DatadogSpan {
     } else {
       const traceId = spanContext._traceId
       const parentId = spanContext._parentId
-      const time = trace.startTime
+      const time = trace.startTime // TODO: update time on new segment
 
       trace.active = 1
       trace.lastIndex = 0
       trace.segmentId = ++segmentId
 
       startSegmentChannel.publish({ parentId, segmentId, time, traceId })
     }
+
+    spanContext.segmentId = trace.segmentId
   }
 
   _initContext (props) {