Comparing versions after upgrade has extra changes not made by the user

Steps

1. Upgrade from Confluence < 6 to Confluence 6+
2. Edit a page and make some minor changes
3. Check the history and compare to the previous version

What happened

It looks confluence editor tried to add some additional formatting (things like <div class="content-wrapper">, class="wrapped") to the content (specifically to table) if they are not present during the editing. And some spaces ( ) are replaced with "<br/>" within a table as well.

What should have happened

The expectation is that no other changes are present in the comparison as the user didn't make them.

Reason

Confluence does lazy content migrations on upgrade when changes are needed due to changes in the way the content is presented and edited. Rather than upgrading the content in an upgrade task, Confluence performs the changes live in the editor the next time the page is opened.