Re: comment-dwim on blank lines

[martin rudalics]

Glen, if you're going to spend some time on newcomment please have a
look at the below.  I once asked Stefan but apparently he forgot.

With emacs -Q customize `comment-style' to box or box-multi.  In
*scratch* insert

(foo bar baz)

set the region around bar and do `comment-region'.  Gets you

(foo ;; bar ;; baz)

instead of

(foo ;; bar ;;
     baz)

Responsible is the

    (when block (unless ce (setq ce (comment-string-reverse cs))))

line in `comment-region-internal' which makes the subsequent

      (unless (or ce (eolp)) (insert "\n") (indent-according-to-mode))

fail.  I proposed the attached patch.

*** newcomment.el.~1.101.~      Mon Apr  2 07:45:08 2007
--- newcomment.el       Thu May 10 10:38:22 2007
***************
*** 926,941 ****
  the region rather than at left margin."
    ;;(assert (< beg end))
    (let ((no-empty (not (or (eq comment-empty-lines t)
!                          (and comment-empty-lines (zerop (length ce)))))))
      ;; Sanitize CE and CCE.
      (if (and (stringp ce) (string= "" ce)) (setq ce nil))
      (if (and (stringp cce) (string= "" cce)) (setq cce nil))
      ;; If CE is empty, multiline cannot be used.
      (unless ce (setq ccs nil cce nil))
      ;; Should we mark empty lines as well ?
      (if (or ccs block lines) (setq no-empty nil))
      ;; Make sure we have end-markers for BLOCK mode.
!     (when block (unless ce (setq ce (comment-string-reverse cs))))
      ;; If BLOCK is not requested, we don't need CCE.
      (unless block (setq cce nil))
      ;; Continuation defaults to the same as CS and CE.
--- 926,943 ----
  the region rather than at left margin."
    ;;(assert (< beg end))
    (let ((no-empty (not (or (eq comment-empty-lines t)
!                          (and comment-empty-lines (zerop (length ce))))))
!       ce-sanitized)
      ;; Sanitize CE and CCE.
      (if (and (stringp ce) (string= "" ce)) (setq ce nil))
+     (setq ce-sanitized ce)
      (if (and (stringp cce) (string= "" cce)) (setq cce nil))
      ;; If CE is empty, multiline cannot be used.
      (unless ce (setq ccs nil cce nil))
      ;; Should we mark empty lines as well ?
      (if (or ccs block lines) (setq no-empty nil))
      ;; Make sure we have end-markers for BLOCK mode.
!     (when (and block (not ce)) (setq ce (comment-string-reverse cs)))
      ;; If BLOCK is not requested, we don't need CCE.
      (unless block (setq cce nil))
      ;; Continuation defaults to the same as CS and CE.
***************
*** 945,951 ****
        (goto-char end)
        ;; If the end is not at the end of a line and the comment-end
        ;; is implicit (i.e. a newline), explicitly insert a newline.
!       (unless (or ce (eolp)) (insert "\n") (indent-according-to-mode))
        (comment-with-narrowing beg end
        (let ((min-indent (point-max))
              (max-indent 0))
--- 947,954 ----
        (goto-char end)
        ;; If the end is not at the end of a line and the comment-end
        ;; is implicit (i.e. a newline), explicitly insert a newline.
!       (unless (or ce-sanitized (eolp))
!       (insert "\n") (indent-according-to-mode))
        (comment-with-narrowing beg end
        (let ((min-indent (point-max))
              (max-indent 0))
***************
*** 1163,1169 ****
                               (buffer-substring (point)
                                                 (progn (move-to-left-margin)
                                                        (point)))))))))))))
!                     

  ;;;###autoload
  (defun comment-indent-new-line (&optional soft)
--- 1166,1172 ----
                               (buffer-substring (point)
                                                 (progn (move-to-left-margin)
                                                        (point)))))))))))))
! 

  ;;;###autoload
  (defun comment-indent-new-line (&optional soft)