Hmm. I think a plugin could do this…
RSS Link2Home plugin:
Download zip | View source
To use this, your index.php–or home.php if one is in your theme–must provide an unique ID attribute (also known as a fragment identifier) to each post so the link actually sends the reader to the post’s location on the home page. The plugin assumes the format post-123
for an ID attribute value, where 123 is the numeric post ID for each post.
Here’s an example of how it would be set up in a template:
<h2 id="post-<?php the_ID(); ?>"><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
The “post-” prefix can be altered if you want to use (or are using) something else by editing the $anchor_prefix
variable within the plugin file.
EDIT note: This is not presently a perfect solution. For one, comment links in RSS2 are broken by it. But mainly the problem is permalinks under any condition, including category, archive, and single post queries, will be converted. I’ve no idea how to avoid the former, but I’m looking at how the plugin can bypass the latter.