Please read the blog post that introduces this fix: http://umbraco.com/follow-us/blog-archive/2013/2/1/umbraco-4114-released.aspx
Upgraders from 4.10.x or 4.11.x to 6.0.x should also run this to fix their paths. As of 4.11.4 and 6.0.0 the path is not corrupted any more.
This is a developer dashboard control to fix database issues based on a bug introduced in 4.10. This bug causes the descendants of any node that is moved to not have their path or level updated in the database. This will cause inconsistencies when trying to retreive the Descendants of a node using the business logic APIs (not the published APIs). This bug may also cause a YSOD to occur when publishing, full details can be found here: