From c522aaafde483a7c0127eab008b1274de8fd4fda Mon Sep 17 00:00:00 2001
From: Ryan Hendrickson <ryan.hendrickson@alum.mit.edu>
Date: Mon, 23 Oct 2017 11:57:20 -0400
Subject: [PATCH] nixos/postfix: allow dollar parameters in lists (#30612)

---
 nixos/doc/manual/release-notes/rl-1803.xml | 8 +++++++-
 nixos/modules/services/mail/postfix.nix    | 2 +-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/nixos/doc/manual/release-notes/rl-1803.xml b/nixos/doc/manual/release-notes/rl-1803.xml
index 47522fe3cc9..6fa14b55386 100644
--- a/nixos/doc/manual/release-notes/rl-1803.xml
+++ b/nixos/doc/manual/release-notes/rl-1803.xml
@@ -55,7 +55,13 @@ following incompatible changes:</para>
 
 <itemizedlist>
   <listitem>
-    <para></para>
+    <para>
+      Dollar signs in options under <option>services.postfix</option> are
+      passed verbatim to Postfix, which will interpret them as the beginning of
+      a parameter expression. This was already true for string-valued options
+      in the previous release, but not for list-valued options. If you need to
+      pass literal dollar signs through Postfix, double them.
+    </para>
   </listitem>
 </itemizedlist>
 
diff --git a/nixos/modules/services/mail/postfix.nix b/nixos/modules/services/mail/postfix.nix
index ad4e5814984..2185484827d 100644
--- a/nixos/modules/services/mail/postfix.nix
+++ b/nixos/modules/services/mail/postfix.nix
@@ -28,7 +28,7 @@ let
 
   mainCf = let
     escape = replaceStrings ["$"] ["$$"];
-    mkList = items: "\n  " + concatMapStringsSep "\n  " escape items;
+    mkList = items: "\n  " + concatStringsSep "\n  " items;
     mkVal = value:
       if isList value then mkList value
         else " " + (if value == true then "yes"