you will see the page added by user A in the Special:Book
While collaboration should be encouraged (see T46185) I think this is pretty
unexpected.
Version: master
Severity: minor
See Also: T46185: Store created books on a server, not in the browser
To clarify, this is about the current (non-saved) collection in the process of being gathered, not about the actual output. The collection, when submitted for rendering, is only accessible at an URL containing something like collection_id=64d6f54fa718e186 (safer than most passwords).
Fully agree, thanks. I actually wonder how much this is an actual problem. One could imagine for example, that anonymous user has this feature enabled as well and then this kind of behavior is correct (same set of pages available regardless whether logged in or out).
(In reply to Marcin Cieślak from comment #2)
I actually wonder how much this is an actual problem.
I was tempted to close it invalid/wontfix. :) As currently phrased I think it's valid in principle, but I don't know what expectations registered users with shared computers have.