[mifuha]

Rationale for this change

Add a test for a transaction that adds a nullable column and appends a row, while another writer commits first.

The test checks that the first writer retries and keeps the new column, its field ID, and all three rows. It also checks the snapshot's parent and schema ID, and that reloading the table gives the same result.

Are these changes tested?

After updating from main on 4 November, local validation on Python 3.12 passed: 4,479 tests passed, 5 skipped and 129 deselected. make lint also passed. All eight GitHub CI workflows passed, including integration tests and documentation.

Are there any user-facing changes?

No. This adds test coverage only.

AI-assisted implementation.

[mifuha]

Hi @kevinjqliu, just following up on this PR.

I saw that #4025 fixed the setup-uv allowlist issue, but this PR still shows the earlier CI startup failures. Should I update my branch from main to pick up the fix?
This PR only adds regression coverage, and the tests and lint checks passed locally. I’d appreciate a review when convenient, or a pointer to the right reviewer.

Thanks!

[mifuha]

Hi @Fokko, I’ve updated the branch from main and all eight CI workflows now pass. This PR adds regression coverage for schema changes and appends during commit retry. Could you take a look when you have time? Thanks!