Pasting a URL in the external link added by the WYSIWYG makes the URL disappear

Summary

Using the WYSIWYG editor in visual mode and using the button to add an external link, the link will disappear if you simply replace the example URL.

Steps to Reproduce

1. Create a new issue.
2. In the issue description, click the Link button and click on External link. The following text will be inserted in the description:

   [link title|http://example.com]
   

3. Replace http://example.com with an external URL.

Expected Results

The URL is replaced and displayed in the editor.

Actual Results

The whole URL wiki markup code disappears as soon as you paste the external URL.

Notes

This happens with the WYSIWYG visual editor both in comments and the issue description.

Workaround

Use text mode to add the external link.