Getting data from nested editable with newly pasted widget inside throws an error

[Comandeer]

Are you reporting a feature request or a bug?

Bug

Provide detailed reproduction steps (if any)

1. Open https://jsfiddle.net/31dh68nv/
2. Open console.
3. Select and copy widget.
4. Paste into widget's caption.

Expected result

There is no error in the console.

Actual result

There is error thrown:

(index):54 Uncaught TypeError: Cannot read property 'editables' of undefined
    at ckeditor.js:1116
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.htmlParser.element.forEach (ckeditor.js:284)
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.htmlParser.element.forEach (ckeditor.js:284)
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.htmlParser.element.forEach (ckeditor.js:284)
    at window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.htmlParser.element.forEach (ckeditor.js:284)
    at a.<anonymous> (ckeditor.js:1115)
    at a.c (ckeditor.js:10)
    at a.<anonymous> (ckeditor.js:11)
    at a.window.CKEDITOR.window.CKEDITOR.dom.CKEDITOR.editor.CKEDITOR.editor.fire (ckeditor.js:13)
    at CKEDITOR.htmlDataProcessor.toDataFormat (ckeditor.js:305)

Other details

• Installed CKEditor plugins: widget

Error is thrown only if getData is called from inside selectionChange callback. It does not throw in paste or afterPaste events. The order of events is:

1. paste
2. selectionChange (may be multiple)
3. afterPaste

selectionChange in such scenario is fired in a weird moment, when pasted widget is already inside widget's content, but it's not upcasted yet.

Spinoff #1468.

[f1ames]

Related to #1462.

[uladzimir-miadzinski]

when will the fix?