A few questions about open-line

A few questions about open-line

[Artur Malabarba]

For reference, the function:

(defun open-line (n)
  "Insert a newline and leave point before it.
If there is a fill prefix and/or a `left-margin', insert them
on the new line if the line would have been blank.
With arg N, insert N newlines."
  (interactive "*p")
  (let* ((do-fill-prefix (and fill-prefix (bolp)))
     (do-left-margin (and (bolp) (> (current-left-margin) 0)))
     (loc (point-marker))
     ;; Don't expand an abbrev before point.
     (abbrev-mode nil))
    (newline n)
    (goto-char loc)
    (while (> n 0)
      (cond ((bolp)
         (if do-left-margin (indent-to (current-left-margin)))
         (if do-fill-prefix (insert-and-inherit fill-prefix))))
      (forward-line 1)
      (setq n (1- n)))
    (goto-char loc)
    (end-of-line)))

1. The docstring claims that "If there is a fill prefix and/or a
`left-margin', insert them
on the new line". However, the code actually applies the prefix and
left-margin on the old line, not the new one. Should I fix that or did
I miss something?

2. After the last (goto-char loc), is there any situation where the
point isn't already at the end of the line? Why is that end-of-line
necessary?

3. I think, when electric-indent-mode is on, open-line should indent
the line that was created below if it isn't empty. May I go ahead?

Re: A few questions about open-line

[bruce.connor.am]

> 1. The docstring claims that "If there is a fill prefix and/or a
> `left-margin', insert them
> on the new line". However, the code actually applies the prefix and
> left-margin on the old line, not the new one. Should I fix that or did
> I miss something?

Actually, it looks it's the docstring that is off here. I think it
should say "insert them on the new line.  If the old line would be
left empty, insert them on the old line too.".

Re: A few questions about open-line

[Artur Malabarba]

> 2. After the last (goto-char loc), is there any situation where the
> point isn't already at the end of the line? Why is that end-of-line
> necessary?

After a lot of testing, I see it's necessary in case a left-margin was inserted.