Feed excerpts are missing important filter formatting

[mdgl]

Excerpts included in feeds are missing important formatting because the relevant filters are not applied (e.g. wpautop).

In file wp-includes/feed.php, function the_excerpt_rss() does not apply the same filters as the_excerpt() whilst results in lost formatting instructions. By comparison, function the_content_feed() ensures that the same filters declared for the_content() are applied.

A suggested patch is attached. Note that for symmetry between the_excerpt_rss() and the_content_feed() this patch also removes the (unnecessary?) filter ent2ncr() from the_excerpt_rss() and retains the (controversial?) escaping for CDATA blocks (see #3670).

A few related issues are worth mentioning. Firstly, shortcodes are still not applied to excerpts (see #7093). Also, the (obsolete?) RDF feed does not make use of a CDATA block unlike those for RSS, RSS2 and Atom (see #20888). Finally, a similar problem occurs with comment text in feeds (see #16466).

[raamdev]

@mdgl Thanks for the report. I'm sorry that you never got a reply on this!

I tried testing your patch but it did not apply cleanly for me. Could you please submit an updated patch?

[mdgl]

Patch refreshed for trunk. Earlier caveats still apply. It remains both surprising and disappointing that WordPress doesn't have a clean and consistent way of dealing with fundamental concepts such as the_content and the_excerpt. We mess with this stuff far too much and in different ways.

[raamdev]

@mdgl Thank you for the updated patch. I've confirmed that it applies cleanly to trunk.

[chriscct7]

Refreshed patch