bug#45941: [PATCH] add option to mark buffer as modified after reading new message

["Andrea G. Monaco" <andrea.monaco@autistici.org>]

  > The first line of the docstring should be a complete sentence.
  > Andreas.

Thanks, I didn't know that. I fixed it and also chose a more fitting
name for the variable.


diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 29460cc20f..749cdd5891 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -686,6 +686,9 @@ rmail-show-mime-function
 This function is called when `rmail-enable-mime' is non-nil.
 The package providing MIME support should set this.")
 
+(defvar rmail-showing-new-message-sets-modified nil
+  "If non-nil, showing a new message sets the modified flag for the RMAIL buffer.")
+
 ;;;###autoload
 (defvar rmail-insert-mime-forwarded-message-function nil
   "Function to insert a message in MIME format so it can be forwarded.
@@ -2747,10 +2750,11 @@ rmail-show-message-1
            (t (setq rmail-current-message msg)))
       (with-current-buffer rmail-buffer
        (setq header-style rmail-header-style)
-       ;; Mark the message as seen, but preserve buffer modified flag.
-       (let ((modiff (buffer-modified-p)))
+        ;; Mark the message as seen, but preserve buffer modified flag,
+       ;; unless rmail-showing-new-message-sets-modified is non-nil
+        (let ((modiff (buffer-modified-p)))
          (rmail-set-attribute rmail-unseen-attr-index nil)
-         (unless modiff
+         (unless rmail-showing-new-message-sets-modified
            (restore-buffer-modified-p modiff)))
        ;; bracket the message in the mail
        ;; buffer and determine the coding system the transfer encoding.


-- 
Andrea G. Monaco
Hacker, mathematician, lgbt+ activist
"Hope will never be silent!", H. Milk