This avoids generating review drafts for merge commits unless the merge commit has modifications to the review draft (which I hope means that it's different from all parents of the merge).
The code prior to this change tries to generate a review draft if the first parent of the merge commit introduces a review draft. (This happens if "git merge main" is done on a feature branch and main has introduced a review draft.)
Indeed, it's for pull requests... and I do think merge commits are useful on pull requests since they let the commit history of the pull request reflect reality.
This avoids generating review drafts for merge commits unless the merge commit has modifications to the review draft (which I hope means that it's different from all parents of the merge).
The code prior to this change tries to generate a review draft if the first parent of the merge commit introduces a review draft. (This happens if "git merge main" is done on a feature branch and main has introduced a review draft.)
This matches the change in https://github.com/whatwg/html-build/pull/284 .