OtelTracer does not set parent context when explicitly specified

[jamesmoessis]

The following code does not work with the OtelTracer. We expect that the span has trace ID equal to the one we specified in the parent context, but it actually ends up using Context.current().

@Test
void manualparentContext() {
    TraceContext parentCtx =
            tracer.traceContextBuilder()
                    .traceId(TRACE_ID)
                    .spanId(SPAN_ID)
                    .sampled(SAMPLING_FLAG)
                    .build();

    Span span =
            tracer.spanBuilder().setParent(parentCtx)
                    .name("test-span").start();

    assertThat(span.context().traceId()).isEqualTo(TRACE_ID);
}

This can be achieved using the OTel API in such a way that this repo does not seem to implement:

io.opentelemetry.api.trace.Tracer otelTracer;

@Test
void manualParentContextOtel() {
    SpanContext spanCtx  = SpanContext
            .createFromRemoteParent(
                    TRACE_ID,
                    SPAN_ID,
                    TraceFlags.fromByte((byte)1),
                    TraceState.getDefault());
    Context ctx = Context.current().with(io.opentelemetry.api.trace.Span.wrap(spanCtx));

    io.opentelemetry.api.trace.Span span = otelTracer
            .spanBuilder("s")
            .setParent(ctx)
            .startSpan();
    try (Scope ignored = span.makeCurrent()) {
        doStuff();
    } finally {
        span.end();
    }
}

I believe the problem is in the toOtelContext() method, and doesn't use the Span.wrap() method.

[jamesmoessis]

Thankyou for fixing!!