X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=lisp%2Fmm-encode.el;h=669df35810dd7bd65199d9bedf39036683c73047;hb=3231d171219d5742818bec2054ba39b478cff6cc;hp=272dc82548f9d832982bbe071c7617b0fd60068b;hpb=23c969058026ed1e55687f9942acf0d2e406fb01;p=elisp%2Fgnus.git-

diff --git a/lisp/mm-encode.el b/lisp/mm-encode.el
index 272dc82..669df35 100644
--- a/lisp/mm-encode.el
+++ b/lisp/mm-encode.el
@@ -1,5 +1,5 @@
-;;; mm-encode.el --- Functions for encoding MIME things
-;; Copyright (C) 1998 Free Software Foundation, Inc.
+;;; mm-encode.el --- Functions for encoding MIME things 
+;; Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
 
 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
 ;;	MORIOKA Tomohiko <morioka@jaist.ac.jp>
@@ -25,15 +25,30 @@
 ;;; Code:
 
 (require 'mail-parse)
-(require 'mailcap)
+(require 'gnus-mailcap)
 
 (defvar mm-content-transfer-encoding-defaults
-  '(("text/.*" quoted-printable)
-    ("message/rfc822" quoted-printable)
+  '(("text/x-patch" 8bit)
+    ("text/.*" qp-or-base64)
+    ("message/rfc822" 8bit)
     ("application/emacs-lisp" 8bit)
     ("application/x-patch" 8bit)
-    (".*" base64))
-  "Alist of regexps that match MIME types and their encodings.")
+    (".*" qp-or-base64))
+  "Alist of regexps that match MIME types and their encodings.
+If the encoding is `qp-or-base64', then either quoted-printable
+or base64 will be used, depending on what is more efficient.")
+
+(defvar mm-use-ultra-safe-encoding nil
+  "If non-nil, use encodings aimed at Procrustean bed survival.
+
+This means that textual parts are encoded as quoted-printable if they
+contain lines longer than 76 characters or starting with \"From \" in
+the body.  Non-7bit encodings (8bit, binary) are generally disallowed.
+This is to reduce the probability that a broken MTA or MDA changes the
+message.
+
+This variable should never be set directly, but bound before a call to
+`mml-generate-mime' or similar functions.")
 
 (defun mm-insert-rfc822-headers (charset encoding)
   "Insert text/plain headers with CHARSET and ENCODING."
@@ -57,30 +72,36 @@
       "application/octet-stream"
     (mailcap-extension-to-mime (match-string 0 file))))
 
+(defun mm-safer-encoding (encoding)
+  "Return a safer but similar encoding."
+  (cond
+   ((memq encoding '(7bit 8bit quoted-printable)) 'quoted-printable)
+   ;; The remaing encodings are binary and base64 (and perhaps some
+   ;; non-standard ones), which are both turned into base64.
+   (t 'base64)))
+
 (defun mm-encode-content-transfer-encoding (encoding &optional type)
   (cond
    ((eq encoding 'quoted-printable)
-    (quoted-printable-encode-region (point-min) (point-max)))
+    (quoted-printable-encode-region (point-min) (point-max) t))
    ((eq encoding 'base64)
     (when (equal type "text/plain")
       (goto-char (point-min))
       (while (search-forward "\n" nil t)
 	(replace-match "\r\n" t t)))
-    (condition-case ()
+    (condition-case error
 	(base64-encode-region (point-min) (point-max))
-      (error nil)))
+      (error
+       (message "Error while decoding: %s" error)
+       nil)))
    ((memq encoding '(7bit 8bit binary))
+    ;; Do nothing.
     )
    ((null encoding)
+    ;; Do nothing.
     )
-   ;;((eq encoding 'x-uuencode)
-   ;; (condition-case ()
-   ;;	(uudecode-encode-region (point-min) (point-max))
-   ;;   (error nil)))
    ((functionp encoding)
-    (condition-case ()
-	(funcall encoding (point-min) (point-max))
-      (error nil)))
+    (ignore-errors (funcall encoding (point-min) (point-max))))
    (t
     (message "Unknown encoding %s; defaulting to 8bit" encoding))))
 
@@ -91,7 +112,12 @@ The encoding used is returned."
 	 (encoding
 	  (or (and (listp type)
 		   (cadr (assq 'encoding type)))
-	      (mm-content-transfer-encoding mime-type))))
+	      (mm-content-transfer-encoding mime-type)))
+	 (bits (mm-body-7-or-8)))
+    ;; We force buffers that are 7bit to be unencoded, no matter
+    ;; what the preferred encoding is.
+    (when (eq bits '7bit)
+      (setq encoding bits))
     (mm-encode-content-transfer-encoding encoding mime-type)
     encoding))
 
@@ -109,14 +135,35 @@ The encoding used is returned."
   (insert "\n"))
 
 (defun mm-content-transfer-encoding (type)
-  "Return a CTE suitable for TYPE."
+  "Return a CTE suitable for TYPE to encode the current buffer."
   (let ((rules mm-content-transfer-encoding-defaults))
     (catch 'found
       (while rules
 	(when (string-match (caar rules) type)
-	  (throw 'found (cadar rules)))
+	  (throw 'found
+		 (let ((encoding 
+			(if (eq (cadar rules) 'qp-or-base64)
+			    (mm-qp-or-base64)
+			  (cadar rules))))
+		   (if mm-use-ultra-safe-encoding
+		       (mm-safer-encoding encoding)
+		     encoding))))
 	(pop rules)))))
 
+(defun mm-qp-or-base64 ()
+  (save-excursion
+    (let ((limit (min (point-max) (+ 2000 (point-min))))
+	  (n8bit 0))
+      (goto-char (point-min))
+      (skip-chars-forward "\x20-\x7f\r\n\t" limit)
+      (while (< (point) limit)
+	(incf n8bit)
+	(forward-char 1)
+	(skip-chars-forward "\x20-\x7f\r\n\t" limit))
+      (if (< (* 6 n8bit) (- limit (point-min)))
+	  'quoted-printable
+	'base64))))
+
 (provide 'mm-encode)
 
 ;;; mm-encode.el ends here