Incorrect author is listed on a change-less publish

[NightJar]

An publish action that makes no changes is recorded with a snapshot. The snapshot however lists the previous author as the author for the newest snapshot.

This causes much confusion, particularly in cases concerning #50 - a common case as no page level content has changed, only related items reached via a cascading publish.

Recreation

• A new project with versioned-snapshot-admin & 2 users (e.g. Default Admin & a Content Editor)
• /admin/pages/edit/show/2 click Save & Publish
• 👀 view history, see a single entry with no author at all. ❌
• Edit the page's content, save and publish again.
• 👀 view history, see a new entry listing the active user ✅
• Using the other user click Save & Publish (without editing)
• 👀 view history, see a new entry listing the user that is not active (did not complete the latest publish). ❌

User "Editor" (a "Content Author") publishes without changes

User "Editor" (a "Content Author") publishes with changes

User "Default Admin" (an "Administrator") publishes without changes

[unclecheese]

Should be resolved by: a06a95f

Author was being listed as the "origin version" author, but in changeless publish (or a publish of only "owned" content, e.g. blocks), there was no new version being created for the page, so the previous publisher was showing. Snapshot actions track their own authors and maintain that state independently.

[NightJar]

a06a95f indeed has resolved this issue for new entries.
However is appears old entries have been lost to time by this change.
I have not downgraded this project to re-confirm there were values there to begin with yet. If this is the case, I suspect it might be related to silverstripe/silverstripe-versioned-snapshots#41

[NightJar]

Indeed, rolling back the testing updates has seen author information return.
Perhaps some kind of migration task or fallback lookup might be best

(edit:) oops, the cross should be against the entry above it, but hopefully you get the idea :)