(rmail-preserve-inbox): New variable.

(rmail-get-new-mail): If rmail-preserve-inbox is non-nil, then
don't truncate the inboxes after retrieving mail from them.

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 30493fea7007179517bd5ae3c98f9c80c835c4e2..ba2b8ae6ad7a2e0e9edc9777ac19ff918ec867e3 100644 (file)
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -60,6 +60,10 @@
 (defvar rmail-pop-password-required nil
   "*Non-nil if a password is required when reading mail using POP.")
 
+(defvar rmail-preserve-inbox nil
+  "*Non-nil if incoming mail should be left in the user's inbox,
+rather than deleted, after it is retrieved.")
+
 ;;;###autoload
 (defvar rmail-dont-reply-to-names nil "\
 *A regexp specifying names to prune of reply to messages.
@@ -891,6 +895,9 @@ file of new mail is not changed or deleted.  Noninteractively, you can
 pass the inbox file name as an argument.  Interactively, a prefix
 argument causes us to read a file name and use that file as the inbox.
 
+If the variable `rmail-preserve-inbox' is non-nil, new mail will
+always be left in inbox files rather than deleted.
+
 This function runs `rmail-get-new-mail-hook' before saving the updated file.
 It returns t if it got any new messages."
   (interactive
@@ -1074,34 +1081,42 @@ It returns t if it got any new messages."
                                             (not (file-exists-p file))))
             nil)
            ((and (not movemail) (not popmail))
-            ;; Try copying.  If that fails (perhaps no space),
-            ;; rename instead.
-            (condition-case nil
+            ;; Try copying.  If that fails (perhaps no space) and
+            ;; we're allowed to blow away the inbox, rename instead.
+            (if rmail-preserve-inbox
                 (copy-file file tofile nil)
-              (error
-               ;; Third arg is t so we can replace existing file TOFILE.
-               (rename-file file tofile t)))
+              (condition-case nil
+                  (copy-file file tofile nil)
+                (error
+                 ;; Third arg is t so we can replace existing file TOFILE.
+                 (rename-file file tofile t))))
             ;; Make the real inbox file empty.
             ;; Leaving it deleted could cause lossage
             ;; because mailers often won't create the file.
-            (condition-case ()
-                (write-region (point) (point) file)
-              (file-error nil)))
+            (if (not rmail-preserve-inbox)
+                (condition-case ()
+                    (write-region (point) (point) file)
+                  (file-error nil))))
            (t
             (let ((errors nil))
               (unwind-protect
                   (save-excursion
                     (setq errors (generate-new-buffer " *rmail loss*"))
                     (buffer-disable-undo errors)
-                    (if rmail-pop-password
-                        (call-process
-                         (or rmail-movemail-program
-                             (expand-file-name "movemail" exec-directory))
-                         nil errors nil file tofile rmail-pop-password)
-                      (call-process
-                       (or rmail-movemail-program
-                           (expand-file-name "movemail" exec-directory))
-                       nil errors nil file tofile))
+                    (let ((args 
+                           (append 
+                            (list (or rmail-movemail-program
+                                      (expand-file-name "movemail"
+                                                        exec-directory))
+                                  nil errors nil)
+                            (if rmail-preserve-inbox 
+                                (list "-p")
+                              nil)
+                            (list file tofile)
+                            (if rmail-pop-password 
+                                (list rmail-pop-password)
+                              nil))))
+                      (apply 'call-process args))
                     (if (not (buffer-modified-p errors))
                         ;; No output => movemail won
                         nil
@@ -1132,7 +1147,8 @@ It returns t if it got any new messages."
            (or (= (preceding-char) ?\n)
                (zerop size)
                (insert ?\n))
-           (setq delete-files (cons tofile delete-files))))
+           (if (not (and rmail-preserve-inbox (string= file tofile)))
+               (setq delete-files (cons tofile delete-files)))))
       (message "")
       (setq files (cdr files)))
     delete-files))