Bulleted/numbered list applied to description list breaks HTML

[Piotrek Koszuliński]

1. Use source (remember about ACF):

<dl><dt>Foo</dt><dd>bar</dd></dl>

2. Make selection in "Foo".
3. Apply bulleted list.

Expected:

<ul><li>Foo</li></ul><dl><dd>bar</dd></dl>

Actual:

<dl><ul><li>Foo</li></ul><dd>bar</dd></dl>

[Piotrek Koszuliński]

I pushed some tests into ​branch:t/12274.

Unfortunately, description list is a special kind of structure which is similar only to ul and ol lists. It requires a wrapper that can contain only specific elements thus must be correctly handled (including splitting and removing emptied fragments, etc.). There's no other example and therefore list plugin does not expect this situation to happen. I looked into the code and from what I saw it will need a lot of changes and very deep analysis. Tests showed also that at least two parts of algorithm are broken.

Workaround for this issue is to remove description list before applying other list. This can be done by listening on list commands' exec events. I plan to implement this workaround in my description list plugin (​https://github.com/Reinmar/ckeditor-descriptionlist) because it's much, much simpler.

[Jakub Ś]

Other issues concerning description lists #16941, #1333.