data loss when clicking links in Preview window

If an edited page has links in them, and the user is in the "Preview" window of the wysiwyg editor, clicking the link replaces the editor window with the new target, as expected.

However if the user has entered new text, it is now lost. Clicking the web browser "back" button returns only an empty editor, or whatever was there before the last edits. This is very user-unfriendly

The previous contents should be restored, or the link should open in a new window (which is probably the easiest fix).