From 03bf8cd4870c281bddc959a799a320e66306e5cd Mon Sep 17 00:00:00 2001
From: Samuel Dionne-Riel <samuel@dionne-riel.com>
Date: Thu, 11 Oct 2018 21:23:11 -0400
Subject: [PATCH] lib/types: enhances separatedString's description

The previous description "string" is misleading in the full options
manual pages; they are actually concatenated strings, with a specific
character.

The empty string version ("types.string") has been special-cased to
provide a better message.

(cherry picked from commit 0808c7cd31aaa329aba21430b8b26c3a233dd83f)
---
 lib/types.nix | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/types.nix b/lib/types.nix
index 4d6ac51c8988..6d8e58dc0be8 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -192,7 +192,10 @@ rec {
     # separator between the values).
     separatedString = sep: mkOptionType rec {
       name = "separatedString";
-      description = "string";
+      description = if sep == ""
+        then "Concatenated string" # for types.string.
+        else "strings concatenated with ${builtins.toJSON sep}"
+      ;
       check = isString;
       merge = loc: defs: concatStringsSep sep (getValues defs);
       functor = (defaultFunctor name) // {