cmd/bbolt: reject overflowing page-item indexes

[immanuwell]

page-item takes itemid as uint64 but then casts it to uint16. So 65536 wraps to 0 and prints the first item. tiny CLI footgun, but pretty real.

Repro:

bbolt page-item test.db <leaf-page-id> 65536

Before: succeeds and prints item 0, kinda yikes.
After: returns an itemid range error before reading the page.

Added a regression test for the wraparound case.

Tests:

go test ./cmd/bbolt/command -count=1
go test $(go list ./... | rg -v '/tests/failpoint$')

go test ./... still hits local failpoint setup failures here (failpoint: failpoint does not exist), unrelated to this change.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: immanuwell
Once this PR has been reviewed and has the lgtm label, please assign tjungblu for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• cmd/bbolt/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[Elbehery]

/ok-to-test

[Elbehery]

@immanuwell thanks for your contribution

Would you kindly share logs from the repro scenario above ?