[Inline] Entire inline editable may be selected and copied from inside

[Piotrek Koszuliński]

1. Open inlineall sample.
2. Focus first editor.
3. Press ctrl+a, ctrl+c.
4. Go to 3rd editor (right one).
5. Paste.
6. Editor was pasted with all classes and attributes.

This may be reproduced on 2nd editable (bottom left) after pressing shift+enter (inserting <br>, which is present in the first editor).

I reproduced this on Chrome and FF (latest and 3.6).

[Piotrek Koszuliński]

Few findings:

1. This issue is reproducible from the beginning.
2. It is reproducible on FF (latest and 3.6) and Webkits.
3. Editable has to be one of h1-h6. Div, paragraphs, aside, etc cannot be copied.
4. At least one <br> has to be inside the editable.
5. This can be reproduced even on bare native editables - so that's not CKEditor interfering here - it's weird behaviour shared between FF and Webkits.

[Garry Yao]

Yeap...even there's a long list of of pre-conditions to occur this bug, it's still pretty often to hit that in a real usage.

The browser is putting there the entire editable (instead of only it's content) in the paste bin, this's one one where "copybin" idea is to be the rescue ;)

IMO the severity of this one can be deferred to 4.0.1, if no easy solution can be found.

[Piotrek Koszuliński]

Temporary fix - heading which is an editable is stripped on paste.

In the future we shouldn't allow this heading to get copied, but to control this we'll need copybin.

[Frederico Caldeira Knabben]

I've committed a small enhancement to the regex.

[Piotrek Koszuliński]

Masterised: ​https://github.com/ckeditor/ckeditor-dev/commit/3cbf8af