Function-Problem

[Klaus Jantzen <k.d.jantzen@mailbox.org>]

Hello,

the attached function should return true if a line contains all blanks
or is empty.

Currently the function returns a quick 'nil' and then the message 

"No catch for tag: --cl-block-nil--, nil"

What is my problem?

=====
(defun blank-line-p ()
  "Returns t if line contains all blanks or is empty"
  (let ((lep (line-end-position))
        (cpp (point)) ; the current position
        (res 0)
       )
    (beginning-of-line)
    (if (re-search-forward "^[ ]+$\|^$" lep t)
        (progn (goto-char cpp) ; line is blank/empty
               (message "t")
               t)
        (progn (goto-char cpp) ; line is not blank/empty
               (message "nil")
               (return nil))
        )
    ) ; end of let
  ) ; end of 'blank-line-p'
====
Thanks for any hint.
-- 

K.D.J.