How to copy current buffer to a temporary buffer

[Cecil Westerhof <Cecil@decebal.nl>]

I want to copy the current buffer to a temporary buffer, to do some
edits on it. (Converting a text file to a html file.)

The following works:
    (defun make-html-file ()
      (interactive)
      (let ((buffer-name (generate-new-buffer-name "tempori.html")))
        (copy-region-as-kill (point-min) (point-max))
        (switch-to-buffer buffer-name)
        (html-mode)
        (yank)))

But the ‘problem’ is that this adds your current buffer to the kill
ring. That is a side effect that should be circumvented.

So I tried the following:
    (defun make-html-file ()
      (interactive)
      (let ((buffer-name (generate-new-buffer-name "tempori.html"))
            (old-buffer (current-buffer)))
        (switch-to-buffer buffer-name)
        (auto-fill-mode 0)
        (insert-buffer-substring old-buffer)
        (html-mode)))

The problem is that this formats the lines and because of this the
regular expressions that are used for the converting do not work
anymore. How can I write the function in such a way that it does not
add to the kill ring, without the lines being formatted?

I could of-course use:
    (pop kill-ring)

in the first function, but could the second function made to work?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof