On Mon, Apr 27, 2015 at 6:11 AM, Stefan Monnier 
<monnier@iro.umontreal.ca> wrote:
>>  +(defun prog-fill-paragraph (&optional justify)
> [...]
>>  +        ;; Filling inside a comment whose comment-end marker is not
>>  +        ;; \n.  This code is meant to be generic, so that it works 
>> for
>>  +        ;; all modes.
> 
> Hmm... so the code doesn't handle the case of comments that end with 
> \n?
> 
> 
>         Stefan

No, I don't think so. When the comment-end marker is \n,
`forward-comment' will leave point at the beginning of the next line,
causing the whole filling code to be skipped. Even when tweaking the
predicate so that the code is run anyway, it doesn't fill the comment
properly. Was it ever intended to do so? I assumed from the comment
that you quoted that it wasn't.

Those kinds of comments seem to be handled well by the default
`fill-paragraph', though.

-- Simen