Move rmail-related functions from gnus-util.el to gnus-rmail.el

* lisp/gnus/gnus-rmail.el: New file with rmail-related functions
moved from gnus-util.el.

* lisp/gnus/gnus-util.el: Move the rmail-related functions to its
own file.  This avoids loading rmail.el when something requires
gnus-util.el.

4 files changed, 148 insertions, 137 deletions

diff --git a/lisp/gnus/gnus-rmail.el b/lisp/gnus/gnus-rmail.el
new file mode 100644
index 00000000000..f9dcc286a68
--- /dev/null
+++ b/lisp/gnus/gnus-rmail.el
@@ -0,0 +1,142 @@
+;;; 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
diff --git a/lisp/gnus/gnus-util.el b/lisp/gnus/gnus-util.el
index a777157f894..8dbdcc83f8b 100644
--- a/lisp/gnus/gnus-util.el
+++ b/lisp/gnus/gnus-util.el
@@ -858,126 +858,9 @@ variables and then do only the assignment atomically."
   `(let ((inhibit-quit gnus-atomic-be-safe))
      ,@forms))
 
-;;; Functions for saving to babyl/mail files.
-
-(require 'rmail)
-(autoload 'rmail-update-summary "rmailsum")
-
 (defvar mm-text-coding-system)
-
 (declare-function mm-append-to-file "mm-util"
                   (start end filename &optional codesys inhibit))
-(declare-function rmail-swap-buffers-maybe "rmail" ())
-(declare-function rmail-maybe-set-message-counters "rmail" ())
-(declare-function rmail-count-new-messages "rmail" (&optional nomsg))
-(declare-function rmail-summary-exists "rmail" ())
-(declare-function rmail-show-message "rmail" (&optional n no-summary))
-;; Macroexpansion of rmail-select-summary:
-(declare-function rmail-summary-displayed "rmail" ())
-(declare-function rmail-pop-to-buffer "rmail" (&rest args))
-(declare-function rmail-maybe-display-summary "rmail" ())
-
-(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."
-  (require 'rmail)
-  (require 'mm-util)
-  (require 'nnmail)
-  ;; 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-output-to-mail (filename &optional ask)
   "Append the current article to a mail file named FILENAME."
@@ -1035,17 +918,6 @@ FILENAME exists and is Babyl format."
 	    (insert-buffer-substring tmpbuf)))))
     (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 "\^_")))
-
 (defun gnus-map-function (funs arg)
   "Apply the result of the first function in FUNS to the second, and so on.
 ARG is passed to the first function."
@@ -1675,6 +1547,11 @@ lists of strings."
     (while overlays
       (delete-overlay (pop overlays)))))
 
+;; This function used to live in this file, but was moved to a
+;; separate file to avoid pulling in rmail.el when requiring
+;; gnus-util.
+(autoload 'gnus-output-to-rmail "gnus-rmail")
+
 (provide 'gnus-util)
 
 ;;; gnus-util.el ends here
diff --git a/lisp/gnus/gnus.el b/lisp/gnus/gnus.el
index afe07ee46f9..1f1c39bb8b5 100644
--- a/lisp/gnus/gnus.el
+++ b/lisp/gnus/gnus.el
@@ -2528,14 +2528,6 @@ are always t.")
      ("babel" babel-as-string)
      ("nnmail" nnmail-split-fancy nnmail-article-group)
      ("nnvirtual" nnvirtual-catchup-group nnvirtual-convert-headers)
-     ;; This is only used in message.el, which has an autoload.
-     ("rmailout" rmail-output)
-     ;; Next two used in gnus-util, which has autoloads, and contrib/sendmail.
-     ("rmail" rmail-count-new-messages rmail-show-message
-      ;; Next two only used in gnus-util.
-      rmail-summary-exists rmail-select-summary)
-     ;; Only used in gnus-util, which has an autoload.
-     ("rmailsum" rmail-update-summary)
      ("gnus-xmas" gnus-xmas-splash)
      ("score-mode" :interactive t gnus-score-mode gnus-score-edit-all-score)
      ("gnus-mh" gnus-summary-save-article-folder
diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el
index c2d14296f94..285369b84cc 100644
--- a/lisp/gnus/message.el
+++ b/lisp/gnus/message.el
@@ -2053,7 +2053,7 @@ You must have the \"hashcash\" binary installed, see `hashcash-path'."
 (autoload 'gnus-groups-from-server "gnus")
 (autoload 'gnus-open-server "gnus-int")
 (autoload 'gnus-output-to-mail "gnus-util")
-(autoload 'gnus-output-to-rmail "gnus-util")
+(autoload 'gnus-output-to-rmail "gnus-rmail")
 (autoload 'gnus-request-post "gnus-int")
 (autoload 'gnus-server-string "gnus")
 (autoload 'message-setup-toolbar "messagexmas")