Reinstate isolation scope pinning in startActiveSpan

Author: andreiborza

packages/opentelemetry/src/tracer.ts

@@ -6,6 +6,7 @@ import {
   _INTERNAL_setSpanForScope,
   _INTERNAL_startInactiveSpan,
   addChildSpanToSpan,
+  getCapturedScopesOnSpan,
   getCurrentScope,
   getDynamicSamplingContextFromSpan,
   getIsolationScope,
@@ -18,6 +19,7 @@ import {
 } from '@sentry/core';
 import type { Span, SpanAttributes, SpanLink } from '@sentry/core';
 import { applyOtelSpanData, applyOtelSpanKind } from './applyOtelSpanData';
+import { SENTRY_FORK_SET_ISOLATION_SCOPE_CONTEXT_KEY } from './constants';
 import { getSamplingDecision } from './utils/getSamplingDecision';
 
 export class SentryTracer implements Tracer {
@@ -66,7 +68,15 @@ export class SentryTracer implements Tracer {
     ) as F;
 
     const span = this.startSpan(name, options, ctx);
-    const ctxWithSpan = trace.setSpan(ctx, span);
+    let ctxWithSpan = trace.setSpan(ctx, span);
+
+    // Run the span's callback under the isolation scope captured when the span was created, so scope state
+    // used or set during the span (tags, breadcrumbs, captured errors) belongs to that span and stays
+    // isolated from other concurrent work. Without this it can land on a different isolation scope.
+    const capturedIsolationScope = getCapturedScopesOnSpan(span as unknown as Span).isolationScope;
+    if (capturedIsolationScope) {
+      ctxWithSpan = ctxWithSpan.setValue(SENTRY_FORK_SET_ISOLATION_SCOPE_CONTEXT_KEY, capturedIsolationScope);
+    }
 
     return context.with(ctxWithSpan, () => {
       _INTERNAL_setSpanForScope(getCurrentScope(), span as unknown as Span);