+(defun mime-text-decode-buffer-maybe (charset &optional encoding)
+ "Decode text of current buffer as CHARSET if ENCODING is actual encoding.
+It code-converts current buffer from network representation specified
+by MIME CHARSET to internal code if ENCODING is not nil, \"7bit\",
+\"8bit\" or \"binary\". CHARSET is symbol of MIME charset.
+See also variable `mime-charset-coding-system-alist'."