POTEL 30 - span.startChild now uses .makeCurrent() by default (#3544)

* Partially fix class loading into bootstrap classloader

* startChild span now makes the child span the current span by default

* changelog

Author: adinauer

CHANGELOG.md

@@ -11,6 +11,8 @@
 - Support spans that are split into multiple batches ([#3539](https://github.com/getsentry/sentry-java/pull/3539))
   - When spans belonging to a single transaction were split into multiple batches for SpanExporter, we did not add all spans because the isSpanTooOld check wasn't inverted.
 - Parse and use `send-default-pii` and `max-request-body-size` from `sentry.properties` ([#3534](https://github.com/getsentry/sentry-java/pull/3534))
+- `span.startChild` now uses `.makeCurrent()` by default ([#3544](https://github.com/getsentry/sentry-java/pull/3544))
+  - This caused an issue where the span tree wasn't correct because some spans were not added to their direct parent 
 - Partially fix bootstrap class loading ([#3543](https://github.com/getsentry/sentry-java/pull/3543))
   - There was a problem with two separate Sentry `Scopes` being active inside each OpenTelemetry `Context` due to using context keys from more than one class loader.
 

sentry-opentelemetry/sentry-opentelemetry-extra/src/main/java/io/sentry/opentelemetry/OtelSpanWrapper.java

@@ -129,7 +129,11 @@ public OtelSpanWrapper(
       return NoOpSpan.getInstance();
     }
 
-    return scopes.getOptions().getSpanFactory().createSpan(scopes, spanOptions, spanContext, this);
+    final @NotNull ISpan childSpan =
+        scopes.getOptions().getSpanFactory().createSpan(scopes, spanOptions, spanContext, this);
+    // TODO [POTEL] spanOptions.isBindToScope with default true?
+    childSpan.makeCurrent();
+    return childSpan;
   }
 
   @Override