(mail-quote-printable, mail-unquote-printable)

(mail-unquote-printable-hexdigit): New functions.

diff --git a/lisp/mail/mail-utils.el b/lisp/mail/mail-utils.el
index 71dd1950728abc3db1991fa31d9857a146da2982..954505442481b37198353fe648e8962c00fd92fb 100644 (file)
--- a/lisp/mail/mail-utils.el
+++ b/lisp/mail/mail-utils.el
@@ -57,6 +57,49 @@ from START (inclusive) to END (exclusive)."
     (concat (substring string 0 start)
            (substring string end nil))))
 
+(defun mail-quote-printable (string &optional wrapper)
+  "Convert a string to the \"quoted printable\" Q encoding.
+If the optional argument WRAPPER is non-nil,
+we add the wrapper characters =3D?ISO-8859-1?Q?....?=3D."
+  (let ((i 0) (result ""))
+    (save-match-data
+      (while (string-match "[?=\"\200-\377]" string i)
+       (setq result
+             (concat result (substring string i (match-beginning 0))
+                     (upcase (format "=%02x"
+                                     (aref string (match-beginning 0))))))
+       (setq i (match-end 0)))
+      (if wrapper
+         (concat "=3D?ISO-8859-1?Q?"
+                 result (substring string i)
+                 "?=3D")
+       (concat result (substring string i))))))
+
+(defun mail-unquote-printable-hexdigit (char)
+  (if (>= char ?A)
+      (+ (- char ?A) 10)
+    (- char ?0)))
+
+(defun mail-unquote-printable (string &optional wrapper)
+  "Undo the \"quoted printable\" encoding.
+If the optional argument WRAPPER is non-nil,
+we expect to find and remove the wrapper characters =3D?ISO-8859-1?Q?....?=3D."
+  (save-match-data
+    (and wrapper
+        (string-match "\\`=3D\\?ISO-8859-1\\?Q\\?\\([^?]*\\)\\?" string)
+        (setq string (match-string 1 string)))
+    (let ((i 0) (result ""))
+      (while (string-match "=\\(..\\)" string i)
+       (setq result
+             (concat result (substring string i (match-beginning 0))
+                     (make-string 1
+                                  (+ (* 16 (mail-unquote-printable-hexdigit
+                                            (aref string (match-beginning 1))))
+                                     (mail-unquote-printable-hexdigit
+                                      (aref string (1+ (match-beginning 1))))))))
+       (setq i (match-end 0)))
+      (concat result (substring string i)))))
+
 (defun mail-strip-quoted-names (address)
   "Delete comments and quoted strings in an address list ADDRESS.
 Also delete leading/trailing whitespace and replace FOO <BAR> with just BAR.