Segfault when receiving the traceparent header and otel is not configured

[psdesse-vivlio]

We have encountered this problem with Nginx Unit after upgrading to 1.34. Our setup is:

• No otel configuration block in Nginx Unit configuration;
• Our system has tracing enable on some other components of the system, this result in a traceparent header being present on the request.

In this case, the router of Nginx Unit segfault every time when receiving the request. This seems to be due to a missing check on whereas the otel structure is initialized in nxt_otel_parse_traceparent (not verified but probably too in nxt_otel_parse_tracestate).

We will test, as a workaround, to configure otel in Nginx Unit which should make the problem disappear.

[psdesse-vivlio]

We will test, as a workaround, to configure otel in Nginx Unit which should make the problem disappear.

I confirm that configuring otel in the settings get rid of the problem.