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diff --git a/lisp/gnus/gnus-rmail.el b/lisp/gnus/gnus-rmail.el
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+;;; gnus-rmail.el --- Saving to rmail/babyl files  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2021 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+;;; Functions for saving to babyl/mail files.
+
+(require 'rmail)
+(require 'rmailsum)
+(require 'nnmail)
+
+(defun gnus-output-to-rmail (filename &optional ask)
+  "Append the current article to an Rmail file named FILENAME.
+In Emacs 22 this writes Babyl format; in Emacs 23 it writes mbox unless
+FILENAME exists and is Babyl format."
+  ;; Some of this codes is borrowed from rmailout.el.
+  (setq filename (expand-file-name filename))
+  ;; FIXME should we really be messing with this defcustom?
+  ;; It is not needed for the operation of this function.
+  (if (boundp 'rmail-default-rmail-file)
+      (setq rmail-default-rmail-file filename) ; 22
+    (setq rmail-default-file filename))        ; 23
+  (let ((artbuf (current-buffer))
+	(tmpbuf (gnus-get-buffer-create " *Gnus-output*"))
+        ;; Babyl rmail.el defines this, mbox does not.
+        (babyl (fboundp 'rmail-insert-rmail-file-header)))
+    (save-excursion
+      ;; Note that we ignore the possibility of visiting a Babyl
+      ;; format buffer in Emacs 23, since Rmail no longer supports that.
+     (or (get-file-buffer filename)
+         (progn
+           ;; In case someone wants to write to a Babyl file from Emacs 23.
+           (when (file-exists-p filename)
+             (setq babyl (mail-file-babyl-p filename))
+             t))
+	  (if (or (not ask)
+		  (gnus-yes-or-no-p
+		   (concat "\"" filename "\" does not exist, create it? ")))
+	      (let ((file-buffer (create-file-buffer filename)))
+		(with-current-buffer file-buffer
+                  (if (fboundp 'rmail-insert-rmail-file-header)
+                      (rmail-insert-rmail-file-header))
+		  (let ((require-final-newline nil)
+			(coding-system-for-write mm-text-coding-system))
+		    (gnus-write-buffer filename)))
+		(kill-buffer file-buffer))
+	    (error "Output file does not exist")))
+      (set-buffer tmpbuf)
+      (erase-buffer)
+      (insert-buffer-substring artbuf)
+      (if babyl
+          (gnus-convert-article-to-rmail)
+        ;; Non-Babyl case copied from gnus-output-to-mail.
+        (goto-char (point-min))
+        (if (looking-at "From ")
+            (forward-line 1)
+          (insert "From nobody " (current-time-string) "\n"))
+        (let (case-fold-search)
+          (while (re-search-forward "^From " nil t)
+            (beginning-of-line)
+            (insert ">"))))
+      ;; Decide whether to append to a file or to an Emacs buffer.
+      (let ((outbuf (get-file-buffer filename)))
+	(if (not outbuf)
+            (progn
+              (unless babyl             ; from gnus-output-to-mail
+                (let ((buffer-read-only nil))
+                  (goto-char (point-max))
+                  (forward-char -2)
+                  (unless (looking-at "\n\n")
+                    (goto-char (point-max))
+                    (unless (bolp)
+                      (insert "\n"))
+                    (insert "\n"))))
+              (let ((file-name-coding-system nnmail-pathname-coding-system))
+                (mm-append-to-file (point-min) (point-max) filename)))
+	  ;; File has been visited, in buffer OUTBUF.
+	  (set-buffer outbuf)
+	  (let ((buffer-read-only nil)
+		(msg (and (boundp 'rmail-current-message)
+			  (symbol-value 'rmail-current-message))))
+	    ;; If MSG is non-nil, buffer is in RMAIL mode.
+            ;; Compare this with rmail-output-to-rmail-buffer in Emacs 23.
+	    (when msg
+              (unless babyl
+                (rmail-swap-buffers-maybe)
+                (rmail-maybe-set-message-counters))
+              (widen)
+              (unless babyl
+		(goto-char (point-max))
+		;; Ensure we have a blank line before the next message.
+		(unless (bolp)
+		  (insert "\n"))
+		(insert "\n"))
+              (narrow-to-region (point-max) (point-max)))
+	    (insert-buffer-substring tmpbuf)
+	    (when msg
+              (when babyl
+                (goto-char (point-min))
+                (widen)
+                (search-backward "\n\^_")
+                (narrow-to-region (point) (point-max)))
+	      (rmail-count-new-messages t)
+	      (when (rmail-summary-exists)
+		(rmail-select-summary
+		 (rmail-update-summary)))
+	      (rmail-show-message msg))
+	    (save-buffer)))))
+    (kill-buffer tmpbuf)))
+
+(defun gnus-convert-article-to-rmail ()
+  "Convert article in current buffer to Rmail message format."
+  (let ((buffer-read-only nil))
+    ;; Convert article directly into Babyl format.
+    (goto-char (point-min))
+    (insert "\^L\n0, unseen,,\n*** EOOH ***\n")
+    (while (search-forward "\n\^_" nil t) ;single char
+      (replace-match "\n^_" t t))	;2 chars: "^" and "_"
+    (goto-char (point-max))
+    (insert "\^_")))
+
+;;; gnus-rmail.el ends here