fix: Check span recording state before ending process span

[juandelacruz-calvo]

Summary

This PR adds a check to verify that the subscribe span is still recording before attempting to end the process span in the __exit__ method of the SubscribeOpenTelemetry context manager.

Problem

When the OpenTelemetry subscriber context manager exits, it may attempt to end the process span even when the parent subscribe span has already been terminated or is no longer in a recording state. This leads to log errors like:

/.venv/lib/python3.12/site-packages/opentelemetry/sdk/trace/init.py#L943

                logger.warning("Calling end() on an ended span.")

This happens because using pubsub instrumentation the end() method may be called twice:

• On ack

  python-pubsub/google/cloud/pubsub_v1/subscriber/message.py

  Line 276 in e6294a1

  self.opentelemetry_data.end_process_span()

• Then on __exit__

  python-pubsub/google/cloud/pubsub_v1/subscriber/_protocol/streaming_pull_manager.py

  Lines 174 to 175 in e6294a1

  	with message.opentelemetry_data:
  	callback(message)

Solution

Added a condition self._subscribe_span.is_recording() to the existing check before calling self.end_process_span():

if self._process_span and self._subscribe_span.is_recording():
    self.end_process_span()

Testing

• Existing unit tests pass
• Integration tests with OpenTelemetry context propagation pass

Impact

This is a defensive code change that prevents edge case errors in span management. It should not affect normal operation but provides better handling when spans are terminated in non-standard flows.

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[abbrowne126]

Thanks for putting this together!

[juandelacruz-calvo]

Thanks for putting this together!

Thanks for the review, I'll be away next week, but I'll try to fix the flaky test the week after that 👍