Change a sponsor's logo

Sponsor logos and data are shared globally, so overwriting assets/sponsors/<c>/<id>.png would retroactively change every event that sponsor has ever supported. This project deliberately does not rewrite history — a 2018 event should still show the 2018 logo.

The fix is to keep the old logo under a date-stamped id, repoint past events at it, and give the new logo the original id so current and future events pick it up with no action from their organizers.

When you do not need any of this

If this event is the only one that has ever listed the sponsor, just replace the image and open a normal PR. Check first:

grep -rl "id: <sponsor-id>" data/events/ | sort

One result → simple replacement. More than one → continue.

Run the script

This is the one utility script worth calling directly: it takes arguments, has no interactive loop, and validates its inputs.

./utilities/change_sponsor_logo.sh <sponsor-id> /full/path/to/new-logo.png

Use the exact existing id as it appears in data/sponsors/, not the display name. The path to the new image must be absolute.

It will:

1. Copy the current logo to assets/sponsors/<c>/<id>-before-<YYYYMMDD>.png
2. Copy it again to static/img/sponsors/<id>-before-<YYYYMMDD>.png (the legacy tree — this filename pattern is the one exemption to the CI block on that directory)
3. Copy the current data/sponsors/<id>.yml to <id>-before-<YYYYMMDD>.yml
4. Overwrite assets/sponsors/<c>/<id>.png with the new image
5. Rewrite past events' id: <sponsor-id> to id: <sponsor-id>-before-<YYYYMMDD>

Check what it actually did — this part matters

The script's idea of "past" is a path prefix match on the current calendar year, so it does not exclude future years. An event in a later year gets wrongly rewritten to the old logo.

git diff --stat
git diff -- data/events/ | grep '^[-+].*id:'

Then revert any event whose year is the current year or later:

git checkout -- data/events/2027/

Also check nothing was missed. The script enumerates through git ls-tree HEAD, so an event whose data file is not yet committed is invisible to it:

git status --short data/events/

Finish the sponsor data

Update data/sponsors/<id>.yml with anything else that changed — a new name after a rebrand, a new URL. The -before- copy keeps the old values for the old events.

Confirm the new logo meets the requirements: at least 200px wide (600px preferred), white or transparent background, and it really is a PNG.

Verify

• A past event's sponsor page still shows the old logo
• A current or upcoming event shows the new one
• data/sponsors/<id>-before-<date>.yml exists and has the old values
• Nothing under static/img/sponsors/ changed except the -before-<date> file, or CI blocks the PR
• Preview two events — one old, one current — side by side

Submit

Follow .claude/skills/submit-changes/SKILL.md.

PR title: [SITE] Update <Sponsor> logo, since this is not scoped to one event.

Mention in the PR body which events were repointed to the -before- id, so a reviewer can sanity check the year boundary.