-(mel-define-method-function (mime-encode-string string (nil "8bit"))
- 'identity)
-(mel-define-method-function (mime-decode-string string (nil "8bit"))
- 'identity)
-(mel-define-method mime-encode-region (start end (nil "8bit")))
-(mel-define-method mime-decode-region (start end (nil "8bit")))
-(mel-define-method-function (mime-insert-encoded-file filename (nil "8bit"))
- 'insert-file-contents-as-binary)
-(mel-define-method-function (mime-write-decoded-region
- start end filename (nil "8bit"))
- 'write-region-as-binary)
+(mel-define-backend "8bit" ("7bit"))
+
+(mel-define-backend "binary" ("8bit"))
+
+(defvar mel-b-builtin
+ (and (fboundp 'base64-encode-string)
+ (subrp (symbol-function 'base64-encode-string))))
+
+(when mel-b-builtin
+ (mel-define-backend "base64")
+ (mel-define-method-function (mime-encode-string string (nil "base64"))
+ 'base64-encode-string)
+ (mel-define-method-function (mime-decode-string string (nil "base64"))
+ 'base64-decode-string)
+ (mel-define-method-function (mime-encode-region start end (nil "base64"))
+ 'base64-encode-region)
+ (mel-define-method-function (mime-decode-region start end (nil "base64"))
+ 'base64-decode-region)
+ (mel-define-method mime-insert-encoded-file (filename (nil "base64"))
+ "Encode contents of file FILENAME to base64, and insert the result.
+It calls external base64 encoder specified by
+`base64-external-encoder'. So you must install the program (maybe
+mmencode included in metamail or XEmacs package)."
+ (interactive (list (read-file-name "Insert encoded file: ")))
+ (insert (base64-encode-string
+ (with-temp-buffer
+ (set-buffer-multibyte nil)
+ (insert-file-contents-as-binary filename)
+ (buffer-string))))
+ (or (bolp)
+ (insert "\n"))
+ )
+
+ (mel-define-method-function (encoded-text-encode-string string (nil "B"))
+ 'base64-encode-string)
+ (mel-define-method encoded-text-decode-string (string (nil "B"))
+ (if (and (string-match B-encoded-text-regexp string)
+ (string= string (match-string 0 string)))
+ (base64-decode-string string)
+ (error "Invalid encoded-text %s" string)))
+ )