Inline editor replacing textarea doesn't handle [required]

[John Flatness]

#8031 long ago fixed the issue of [required] on a replaced textarea making submission impossible.

However, it seems that the same problem is present if CKEDITOR.inline is used to replace the textarea rather than CKEDITOR.replace. The code for handling the presence of [required] only seems to exist for themedui, not inline.

It seems the check for "saved [required]" to actually prevent submission and fire events is in onSubmit, and so is already used by both the replace and inline codepaths. It's just that inline doesn't check for the presence of [required] when creating the editor.

[John Flatness]

I think the problem's fairly obvious (and I'd assume known), but in case an example is desired, here's a minimal one:

​https://jsfiddle.net/7sw9hspc/1/

Filling out the input doesn't allow the form to be submitted. Simply changing CKEDITOR.inline to CKEDITOR.replace with no other change does make it work.

[Jakub Ś]

Yes, the inline textarea CKEditor doesn't seem to handle the required attribute. I will set the 4.2 version because this is when handling for required attribute was introduced.