Re: master eaf224f: Repad the Face header in Gnus

[Alex Bochannek]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Alex Bochannek <alex@bochannek.com> writes:
>
>> OK, agreed. Do you want me to submit a patch to revert that code and the
>> tests?
>
> I think that might make sense, but I have no strong feelings about the
> matter.

Here's a patch that reverts that code and the tests.

diff --git a/lisp/gnus/gnus-fun.el b/lisp/gnus/gnus-fun.el
index c2e72aba93..8bca4ffe38 100644
--- a/lisp/gnus/gnus-fun.el
+++ b/lisp/gnus/gnus-fun.el
@@ -206,12 +206,11 @@ gnus-face-encode
 (defun gnus-convert-face-to-png (face)
   "Convert FACE (which is base64-encoded) to a PNG.
 The PNG is returned as a string."
-  (let ((face (gnus-base64-repad face nil nil t)))
-    (mm-with-unibyte-buffer
-      (insert face)
-      (ignore-errors
-       (base64-decode-region (point-min) (point-max)))
-      (buffer-string))))
+  (mm-with-unibyte-buffer
+    (insert face)
+    (ignore-errors
+      (base64-decode-region (point-min) (point-max)))
+    (buffer-string)))
 
 ;;;###autoload
 (defun gnus-convert-png-to-face (file)
diff --git a/lisp/gnus/gnus-util.el b/lisp/gnus/gnus-util.el
index e558f639e4..0f4df34740 100644
--- a/lisp/gnus/gnus-util.el
+++ b/lisp/gnus/gnus-util.el
@@ -1,3 +1,4 @@
+
 ;;; gnus-util.el --- utility functions for Gnus  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 1996-2021 Free Software Foundation, Inc.
@@ -1291,61 +1292,6 @@ gnus-url-unhex-string
     (setq tmp (concat tmp str))
     tmp))
 
-(defun gnus-base64-repad (str &optional reject-newlines line-length no-check)
-  "Take a base 64-encoded string and return it padded correctly.
-Existing padding is ignored.
-
-If any combination of CR and LF characters are present and
-REJECT-NEWLINES is nil, remove them; otherwise raise an error.
-If LINE-LENGTH is set and the string (or any line in the string
-if REJECT-NEWLINES is nil) is longer than that number, raise an
-error.  Common line length for input characters are 76 plus CRLF
-\(RFC 2045 MIME), 64 plus CRLF (RFC 1421 PEM), and 1000 including
-CRLF (RFC 5321 SMTP).
-
-If NOCHECK, don't check anything, but just repad."
-  ;; RFC 4648 specifies that:
-  ;; - three 8-bit inputs make up a 24-bit group
-  ;; - the 24-bit group is broken up into four 6-bit values
-  ;; - each 6-bit value is mapped to one character of the base 64 alphabet
-  ;; - if the final 24-bit quantum is filled with only 8 bits the output
-  ;;   will be two base 64 characters followed by two "=" padding characters
-  ;; - if the final 24-bit quantum is filled with only 16 bits the output
-  ;;   will be three base 64 character followed by one "=" padding character
-  ;;
-  ;; RFC 4648 section 3 considerations:
-  ;; - if reject-newlines is nil (default), concatenate multi-line
-  ;;   input (3.1, 3.3)
-  ;; - if line-length is set, error on input exceeding the limit (3.1)
-  ;; - reject characters outside base encoding (3.3, also section 12)
-  ;;
-  ;; RFC 5322 section 2.2.3 consideration:
-  ;; Because base 64-encoded strings can appear in long header fields, remove
-  ;; folding whitespace while still observing the RFC 4648 decisions above.
-  (when no-check
-    (setq str (replace-regexp-in-string "[\n\r \t]+" "" str)));
-  (let ((splitstr (split-string str "[ \t]*[\r\n]+[ \t]?" t)))
-    (when (and reject-newlines (> (length splitstr) 1))
-      (error "Invalid Base64 string"))
-    (dolist (substr splitstr)
-      (when (and line-length (> (length substr) line-length))
-       (error "Base64 string exceeds line-length"))
-      (when (string-match "[^A-Za-z0-9+/=]" substr)
-       (error "Invalid Base64 string")))
-    (let* ((str (string-join splitstr))
-          (len (length str)))
-      (when (string-match "=" str)
-       (setq len (match-beginning 0)))
-      (concat
-       (substring str 0 len)
-       (make-string (/
-                    (- 24
-                       (pcase (mod (* len 6) 24)
-                         (`0 24)
-                         (n n)))
-                    6)
-                   ?=)))))
-
 (defun gnus-make-predicate (spec)
   "Transform SPEC into a function that can be called.
 SPEC is a predicate specifier that contains stuff like `or', `and',
diff --git a/test/lisp/gnus/gnus-util-tests.el 
b/test/lisp/gnus/gnus-util-tests.el
index 959be7987d..f8d30f6373 100644
--- a/test/lisp/gnus/gnus-util-tests.el
+++ b/test/lisp/gnus/gnus-util-tests.el
@@ -132,41 +132,4 @@ gnus-setdiff
   (should (equal '("1") (gnus-setdiff '(2 "1" 2) '(2))))
   (should (equal '("1" "1") (gnus-setdiff '(2 "1" 2 "1") '(2)))))
 
-(ert-deftest gnus-base64-repad ()
-  (should-error (gnus-base64-repad 1)
-                :type 'wrong-type-argument)
-
-  ;; RFC4648 test vectors
-  (should (equal "" (gnus-base64-repad "")))
-  (should (equal "Zg==" (gnus-base64-repad "Zg==")))
-  (should (equal "Zm8=" (gnus-base64-repad "Zm8=")))
-  (should (equal "Zm9v" (gnus-base64-repad "Zm9v")))
-  (should (equal "Zm9vYg==" (gnus-base64-repad "Zm9vYg==")))
-  (should (equal "Zm9vYmE=" (gnus-base64-repad "Zm9vYmE=")))
-  (should (equal "Zm9vYmFy" (gnus-base64-repad "Zm9vYmFy")))
-
-  (should (equal "Zm8=" (gnus-base64-repad "Zm8")))
-  (should (equal "Zg==" (gnus-base64-repad "Zg")))
-  (should (equal "Zg==" (gnus-base64-repad "Zg====")))
-
-  (should-error (gnus-base64-repad " ")
-                :type 'error)
-  (should-error (gnus-base64-repad "Zg== ")
-                :type 'error)
-  (should-error (gnus-base64-repad "Z?\x00g==")
-                :type 'error)
-  ;; line-length
-  (should-error (gnus-base64-repad "Zg====" nil 4)
-                :type 'error)
-  ;; reject-newlines
-  (should-error (gnus-base64-repad "Zm9v\r\nYmFy" t)
-                :type 'error)
-  (should (equal "Zm9vYmFy" (gnus-base64-repad "Zm9vYmFy" t)))
-  (should (equal "Zm9vYmFy" (gnus-base64-repad "Zm9v\r\nYmFy")))
-  (should (equal "Zm9vYmFy" (gnus-base64-repad "Zm9v\r\nYmFy\n")))
-  (should (equal "Zm9vYmFy" (gnus-base64-repad "Zm9v\r\n YmFy\r\n")))
-  (should (equal "Zm9vYmFy" (gnus-base64-repad "Zm9v \r\n\tYmFy")))
-  (should-error (gnus-base64-repad "Zm9v\r\nYmFy" nil 3)
-                :type 'error))
-
 ;;; gnustest-gnus-util.el ends here

-- 
Alex.