This plugin will make sure that any link you enter to other posts or pages will always stay valid.
When documents that you link to move, change slugs or even when the entire permlink structure changes completely, links will be correct.
It does so by replacing all internal links to their default link format (e.g. /?p=N or /?page_id=M).
Then, when rendering, the default links are changed to the current permlink values.
The plugin can scan existing contents (posts and pages). It will automatically convert all live links and would suggest how to fix links to pages that have moved.
The plugin lets you return all links to their current permlink structure in the database, so if you choose to deactivate the plugin, things go back to the exact way they were.
This plugin is part of SitePress – a collection of plugins that turn WordPress into a fully featured multilingual content management system.