Why baggage header override parent sampling decision

[DanielLiu1123]

Description

From io.sentry.TransactionContext#fromSentryTrace()

  public static @NotNull TransactionContext fromSentryTrace(
      final @NotNull String name,
      final @NotNull TransactionNameSource transactionNameSource,
      final @NotNull String operation,
      final @NotNull SentryTraceHeader sentryTrace,
      final @Nullable Baggage baggage) {
    @Nullable Boolean parentSampled = sentryTrace.isSampled();
    TracesSamplingDecision samplingDecision =
        parentSampled == null ? null : new TracesSamplingDecision(parentSampled);

    if (baggage != null) {
      baggage.freeze();

      Double sampleRate = baggage.getSampleRateDouble();
      // Override the parent sampling decision, makes me confused.
      // So no matter what parent sampling decision is, it becomes true.
      if (sampleRate != null) {
        samplingDecision = new TracesSamplingDecision(true, sampleRate);
      } else {
        samplingDecision = new TracesSamplingDecision(true);
      }
    }

    // ...
  }

[adinauer]

@DanielLiu1123 thanks for raising this. This is a bug. We'll change it so it respects an incoming sampling decision of false.