Function: rfc2047-pad-base64
rfc2047-pad-base64 is a byte-compiled function defined in
rfc2047.el.gz.
Signature
(rfc2047-pad-base64 STRING)
Documentation
Pad STRING to quartets.
Source Code
;; Defined in /usr/src/emacs/lisp/mail/rfc2047.el.gz
(defun rfc2047-pad-base64 (string)
"Pad STRING to quartets."
;; Be more liberal to accept buggy base64 strings. If
;; base64-decode-string accepts buggy strings, this function could
;; be aliased to identity.
(if (= 0 (mod (length string) 4))
string
(when (string-match "=+$" string)
(setq string (substring string 0 (match-beginning 0))))
(pcase (mod (length string) 4)
(0 string)
(1 string) ;; Error, don't pad it.
(2 (concat string "=="))
(3 (concat string "=")))))