fix: guard against short paths in changelog GitHub URL redirect - #9688

Hi @AruneshDwivedi,
I am not familiar with those short changelog url.
Do you have an example of a failing pipeline due to this?

@olblak good question it's a real panic, not a theoretical one.
An image annotated with org.opencontainers.image.changelog: https://github.com/CHANGELOG.md (short URL, changelog at repo root) hits redirectToGitHubRawContent, which does strings.Split(u.Path, "/")[3]. That path only has two segments, so it panics with index out of range [3] with length 2 and kills the whole run. Any pipeline doing dockerimage changelog autodiscovery over such an image crashes. put up a fix in #9689 with a test that repros it. The example in my earlier message used a 4-segment URL by mistake that one doesn't panic; the 2-segment github.com/CHANGELOG.md is the actual trigger.

Thanks for the explanation, why did you created two differernt pullrequest with the same content
#9688 vs #9689