Thanks for your work.

Unfortunately I cannot merge this as-is, as it interferes in xml parsing modes that do not have the same HTML self-closing behaviour.

Okay, what if the doctype is dynamically bound during parsing? Maybe make a toggle to force HTML/XML parsing?

What's the default parsing mode for Plump, actually? Is it XML?

There already is a toggle, it's binding the *tag-dispatchers*.

The default parsing mode is a mix between the two, but that really doesn't matter for this.

If I'm reading it right, then checking for XML tag presence in *tag-dispatchers* should be enough to say whether it's XML-ish parsing or no-XML HTML one?

Something like:

(unless (any (lambda (dispatcher)
               (find (tag-dispatcher-name dispatcher) *tag-dispatchers* :key #'tag-dispatcher-name))
             *xml-tags*)
  #|...|#)

No, that would be an extremely ugly and leaky hack that would break custom dispatcher tables. The fundamental approach of this PR is not mergable.

Okay, what about defining a fully custom default dispatcher (whatever that means, I don't yet understand all this infrastructure of dispatchers) for HTML tags, making it absolutely separate from XML?

I suppose you could install a custom default parser in the dispatch table for html.

Closing this. Thanks for feedback and pointers!