[IE8] Errors while DnD of widgets in the embed widget tests

[Piotrek Koszuliński]

1. Open ​http://tests.ckeditor.dev:1030/tests/plugins/embed/manual/embed
2. Try DnD.
3. Error: Object doesn't support this property or method

				// Don't visit non-editable internals, for example widget's
				// guts (above wrapper, below nested). Still check editable limits,
				// as they are siblings with editable contents.
				if ( !el.hasAttribute( 'contenteditable' ) && el.isReadOnly() )
					continue;

Which means that "el" is something weird.

[Piotrek Koszuliński]

Funny fact is that this issue is reproducible only in that test file. It works fine with code snippets, embedsemantic, image2. If this turns out to be hard to fix, we should check if it's reproducible outside the test, on a real web page. It may not be worth to fight this.

[Jakub Ś]

It seems it is enough to click on grab handle and error pops out.

[Tade0]

Could you describe what kind of drag and drop specifically causes this error?

[Piotrek Koszuliński]

This issue isn't reproducible any more. Earlier it was enough to click the drag handle and error pops out.