From a42dd0c87d27b706574923c89b50519b8893934d Mon Sep 17 00:00:00 2001
From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Fri, 30 Sep 2022 14:48:51 +0200
Subject: [PATCH] Improve message-sendmail-f-is-evil documentation

* lisp/gnus/message.el (message-sendmail-f-is-evil): Move some of
the explanation here.

* lisp/mail/feedmail.el (feedmail-sendmail-f-doesnt-sell-me-out):
Refer to message-sendmail-f-is-evil (bug#58185).
---
 lisp/gnus/message.el  | 19 ++++++++++++++++---
 lisp/mail/feedmail.el | 25 ++++---------------------
 2 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el
index e19ac76869b..084dce65f09 100644
--- a/lisp/gnus/message.el
+++ b/lisp/gnus/message.el
@@ -888,9 +888,22 @@ symbol `never', the posting is not allowed.  If it is the symbol
   ;; FIXME: This is related to `mail-specify-envelope-from' but works
   ;; differently (bug#36937).
   nil
-  "Non-nil means don't add \"-f username\" to the sendmail command line.
-See `feedmail-sendmail-f-doesnt-sell-me-out' for an explanation
-of what the \"-f\" parameter does."
+  "Non-nil means don't add \"-f username\" to the \"sendmail\" command line.
+The \"sendmail\" program has a useful feature to let you set the
+envelope FROM address via a command line option, \"-f\".
+Unfortunately, it also has a widely disliked default behavior of
+disclosing your actual user name anyway by inserting an
+unattractive warning in the headers.  It looks something like
+this:
+
+  X-Authentication-Warning: u1.example.com: niceguy set
+      sender to niceguy@example.com using -f
+
+It is possible to configure \"sendmail\" to not do this, but such a
+reconfiguration is not an option for some users.
+
+Note that this user option is mostly useful for actual \"sendmail\"
+installations, which are rare these days."
   :group 'message-sending
   :link '(custom-manual "(message)Mail Variables")
   :type 'boolean)
diff --git a/lisp/mail/feedmail.el b/lisp/mail/feedmail.el
index 989a8b3cd67..2ae916e3ac1 100644
--- a/lisp/mail/feedmail.el
+++ b/lisp/mail/feedmail.el
@@ -614,29 +614,12 @@ to arrange for the message to get a From: line."
 
 
 (defcustom feedmail-sendmail-f-doesnt-sell-me-out nil
-  "Whether sendmail should issue a warning header if called with \"-f\".
-The sendmail program has a useful feature to let you set the envelope FROM
-address via a command line option, \"-f\".  Unfortunately, it also has a widely
-disliked default behavior of selling you out if you do that by inserting
-an unattractive warning in the headers.  It looks something like this:
-
-  X-Authentication-Warning: u1.example.com: niceguy set
-      sender to niceguy@example.com using -f
-
-It is possible to configure sendmail to not do this, but such a
-reconfiguration is not an option for many users.  As this is the
-default behavior of most sendmail installations, one can mostly
-only wish it were otherwise.  If feedmail believes the sendmail
-program will sell you out this way, it won't use the \"-f\"
-option when calling sendmail.  If it doesn't think sendmail will
-sell you out, it will use the \"-f\" \(since it is a handy
-feature).  You control what feedmail thinks with this variable.
-The default is nil, meaning that feedmail will believe that
-sendmail will sell you out."
+  "If non-nil, call \"sendmail\" with \"-f\".
+See `message-sendmail-f-is-evil' for an explanation of what the
+\"-f\" parameter does."
   :version "24.1"
   :group 'feedmail-headers
-  :type 'boolean
-)
+  :type 'boolean)
 
 
 (defcustom feedmail-deduce-envelope-from t
-- 
2.39.2