What problem does this address?

The new revisions option is a great tool, but at the moment there is no way to revert to the original theme file version of a template or template part, using the revisions tool. The closest you can get is the second save. As a result, users are forced to either manually edit the template (and therefore creating another revision), or use the "clear customizations" option.

The issue with clearing customizations is that it wipes all revisions from the database, so at this point there's no going back, and a potential heart breaking scenario for an un-seasoned user. There's also no second chances with this action - clicking the button does not bring up a warning or modal window to confirm the action or consequence.

What is your proposed solution?

There's likely a few possibilities around this, here's a few options:

• Add a second button, "Clear Customizations and save revision history", wordy, but something along those lines.
• Make it very clear what happens. Add a modal or popup to indicate the consequences of clearing customizations.
• Per the above, add a "Save revisions" checkbox in the modal/pop-up. Internally, a new revision with content copied from the theme file is created.
• Make it transparent to the user and always create a new revision per the above point, by default. For devs or theme creators, potentially create a dev mode, or hook, to disable that action.