@bender-tags: 4.16.1, bug, 4659
@bender-ui: collapsed
@bender-ckeditor-plugins: wysiwygarea, toolbar, basicstyles, sourcearea

## Procedure

1. Copy HTML above the editor.
1. Open source editing area.
1. Paste copied HTML.
1. Switch back to content mode.

### Expected result

* Editor contains paragraph with bold "Test" text followed by a paragraph containing "-->".

### Unexpected result

* Editor is empty.
