GitLab topic filters are case-sensitive on project topics

[DivyamTalwar]

Problem

GitLab connection topic filters normalize configured topics to lowercase, but compare them against project topics without normalizing the project side. A project topic like Backend does not match a config topic or glob such as backend.

Reproduction

Evaluate GitLab project filtering with include.topics: ["backend"] and a project whose API response includes topics: ["Backend"].

Expected

Topic include/exclude matching should be case-insensitive and symmetric between configured topics and project topics.

Actual

Configured topics are lowercased, while project topics retain their original case, so mixed-case GitLab topics can fail otherwise matching filters.

Impact

GitLab sync can unexpectedly include or exclude repositories when GitLab projects use mixed-case topics.

[dubeyharshit0605]

Hi @DivyamTalwar, thanks for the clear reproduction. I’d like to work on this if it’s available for an external contribution.
I’ll first reproduce the mismatch using a GitLab project topic such as Backend with a configured backend filter. Then I’ll add regression coverage for exact and glob-based include/exclude filters, normalize project topics at the same comparison boundary as configured topics, and verify that behavior for other providers remains unchanged.
Could a maintainer confirm that this is the intended direction?