contao/core — pull request #4930 by aschempp (2012-10-15 14:27:55+00:00)
Title: Automatically add isPermaLink=false to RSS feed

According to W3C, an RSS item GUID should be an URL (permalink) by default, but not necessarily. If it's not an URL (and I assume it must be absolute), the attribute "isPermaLink" should be set to "false".