I'm pretty sure this is a wishlist item.

All the pieces are there; someone's just got to want it enough to string them all together.

What Warren said, plus...

Currently very few bits of the web UI acknowledg or interact with a checkout. The settings page recognizes versioned settings, and the /doc/ckout path allows reading local copies of embedded docs (essential when editing them), but that's about it.

I recently ran into another instances of the same problem: /file?ci=ckout URLs also don't work.

I'll acknowledge that this is kind of a strange thing to want to do, but I think it'd be better if ckout simply worked in all places you can give a version string while running under Fossil UI, simply in order to reduce the number of special cases a Fossil user has to keep in mind.

I recently ran into another instances of the same problem: /file?ci=ckout URLs also don't work.

Patches thoughtfully considered! (Sorry, had to say it!)

(That is an interesting suggestion, though. As you certainly know, though, each page has to implement this distinction separately... wait a minute... Isn't that what vtables are for, to allow us to do this transparently? Hmmmm..... you may have just found my next rainy day project.)

Edit: this might just be a matter of extending foci.c to handle ckout as a version number.

this might just be a matter of extending foci.c to handle ckout as a version number.

No. Files in ckout don't necessarily have any other version number. That is, fossil diff --from ckout --to tip may give non-empty output.