From: Eli Zaretskii <eliz@gnu.org>
Date: Tue, 20 Apr 2021 14:58:18 +0000 (+0300)
Subject: Fix Rmail-MIME size estimations
X-Git-Tag: emacs-28.0.90~2801
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=2647b7b78c6c40def8f40a0169a27fd265bd4de4;p=emacs.git

Fix Rmail-MIME size estimations

The quoted-printable estimation was obviously wrong: the size becomes
smaller when decoded, not larger...
* lisp/mail/rmailmm.el (rmail-mime-set-bulk-data): Fix estimations
of decoded MIME attachment.
---

diff --git a/lisp/mail/rmailmm.el b/lisp/mail/rmailmm.el
index e08500a1898..1295a086f52 100644
--- a/lisp/mail/rmailmm.el
+++ b/lisp/mail/rmailmm.el
@@ -784,9 +784,11 @@ directly."
 	   (let ((encoding (rmail-mime-entity-transfer-encoding entity)))
 	     (setq size (- (aref body 1) (aref body 0)))
 	     (cond ((string= encoding "base64")
-		    (setq size (/ (* size 3) 4)))
+                    ;; https://en.wikipedia.org/wiki/Base64#MIME
+		    (setq size (max (* (- size 814) 0.73) 100)))
 		   ((string= encoding "quoted-printable")
-		    (setq size (/ (* size 7) 3)))))))
+                    ;; Assume most of the text is ASCII...
+		    (setq size (/ (* size 5) 7)))))))
 
     (cond
      ((string-match "text/html" content-type)