Table header "scope" attribute is incorrect for 'header: both' option

[Dumluregn]

Type of report

Bug

Provide detailed reproduction steps (if any)

1. Go to https://ckeditor.com/docs/ckeditor4/latest/examples/standardpreset.html.
2. Create 2x2 table with both headers option.
3. Check the source code of table.

Expected result

Table source code should be:

<table border="1" cellpadding="1" cellspacing="1" style="width:500px">
	<thead>
		<tr>
			<th scope="col">&nbsp;</th>
			<th scope="col">&nbsp;</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<th scope="row">&nbsp;</th>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

Actual result

scope attribute is incorrect for [ 1, 1 ] cell:

<table border="1" cellpadding="1" cellspacing="1" style="width:500px">
	<thead>
		<tr>
			<th scope="row">&nbsp;</th>
			<th scope="col">&nbsp;</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<th scope="row">&nbsp;</th>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

Other details

• Browser: every, e.g. Chrome v73.0.x
• OS: macOS 10.14.3
• CKEditor version: 4.11.3
• Installed CKEditor plugins: table

[Dumluregn]

Related to #2881 and #2882.

[bhdzllr]

I created a quick fix for this problem as a plugin by overwriting the "onOk" function for the table dialog. To do this I copied the code from the plugin, the modified parts are marked with "// Modified" in the code: https://gist.github.com/bhdzllr/995d71c2ee725f1cc0565d8f4dabe6c9

I just tested it by myself and did not run any automated tests with this solution.

[Dumluregn]

Thank you for taking your time to solve this issue, feel free to create PR to our repo.

[KarolDawidziuk]

Closed in #5357.