feat: Speculative improvement of handling of unsymbolized profiles

[oleg-kozlyuk-grafana]

No description provided.

[simonswine]

LGTM

[marcsanmi]

I think the current logic doesn't handle locations with empty Line arrays (unsymbolized). When len(ol.Line) == 0, the inner loop never runs, so hasFunctions stays true. This prevents blocks from being tagged as unsymbolized, causing the symbolizer to never run - when enabled. This affects both fully unsymbolized profiles and mixed-symbolization cases (where some locations are symbolized, some aren't). We could check if len(ol.Line) == 0 before the loop and set all flags to false

[oleg-kozlyuk-grafana]

I think the current logic doesn't handle locations with empty Line arrays (unsymbolized). When len(ol.Line) == 0, the inner loop never runs, so hasFunctions stays true. This prevents blocks from being tagged as unsymbolized, causing the symbolizer to never run - when enabled. This affects both fully unsymbolized profiles and mixed-symbolization cases (where some locations are symbolized, some aren't). We could check if len(ol.Line) == 0 before the loop and set all flags to false

Fair point point. I don't think opentelemetry-collector currently produces frames like that, but we might encounter clients with different interpretation of standard. Raised #4517