7 zero-width spaces are not removed from Message Board threads

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X, 7.1.X, 7.2.X, 7.3.X, Master
• Fix Version/s: 7.0.0 DXP FP97, 7.0.X, 7.1.10 DXP FP21, 7.1.X, 7.2.10 DXP FP10, 7.2.10.4 DXP SP4, 7.2.X, 7.3.10 DXP FP1, 7.3.10.1 DXP SP1, 7.3.6 CE GA7, 7.3.X, 7.4.13 DXP GA1, Master
• Component/s: CKEditor
• Labels:
  • ee-ts
  • liferay-dxp-72-sp4
  • liferay-dxp-73-sp1
  • liferay-fixpack-de-97-7010
  • liferay-fixpack-dxp-1-7310
  • liferay-fixpack-dxp-10-7210
  • liferay-fixpack-dxp-21-7110
• Branch Version/s:
  7.3.x, 7.2.x, 7.1.x, 7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/liferay-frontend/liferay-portal/pull/545

Issue
7 zero-width space characters are not auto-removed when composing a Message Board thread using CKEditor. As a result, these characters are included in the thread's contents. The usage of these characters is part of a workaround for a Webkit selection bug (see https://dev.ckeditor.com/ticket/13816).

Steps to reproduce

1. For versions prior to 7.3.x, use the following portal properties to use CKEditor:

   editor.wysiwyg.portal-web.docroot.html.portlet.message_boards.edit_message.bb_code.jsp=ckeditor_bbcode
   editor.wysiwyg.portal-web.docroot.html.portlet.message_boards.edit_message.html.jsp=ckeditor
   

1. Create a new user
2. Go to Content > Message Boards > New Thread
3. In the thread body, create a mention to and select the user from Step 2
4. After the mention, add a new line
5. Publish
6. Inspect the source code of the thread body

See steps.mp4

Expected results
7 ZWS characters are not present in the source

Actual results
7 ZWS characters are present in the source