Compare revisions on 2 different pages

Problem/Motivation

I know this may be minor, but if the revisions list gets too long you can't really do a comparison if the revision you're trying to compare exists on another page.

Steps to reproduce

Using a page with a lot of revisions, select current revision. Go to the next page and select another revision. A message will return "Select two revisions to compare".

Proposed resolution

This is a tricky one. Not sure if the value of one should be stored temporarily or...something else?

Remaining tasks

I'm wondering if I'm overthinking this and/or how often this happens?