Junk HTML is added when inserting a comment while editing it

[JonasCz]

To reproduce:

• Open the dialog with the normal "auto" link

• Double click one of the comments in the list to edit it

• Then click the Insert button without first saving or cancelling the modifications to the comment in the list.

• The following HTML is inserted into the comment area:

  <textarea></textarea><div class="actions"><a>save</a><span class="lsep"> | </span><a>cancel</a></div>

I encountered this when accidentally doubleclicking on a comment in the list, and then inserting it, so it's quite easy to trigger.