From 8737d1783f8a8e0c219ec00dd995e8851fd65b3b Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@shealevy.com>
Date: Thu, 1 May 2014 18:13:06 -0400
Subject: [PATCH] types.attrsOf: Use mergeDefinitions to handle each element

This simplifes typechecking and allows properties to be used inside of
the attribute sets.

This fixes the empty synergy-client and synergy-server services
previously generated on systems with synergy disabled.
---
 lib/types.nix | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/lib/types.nix b/lib/types.nix
index 58fb05b9f0e..a5b9d59e30f 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -126,12 +126,16 @@ in rec {
 
     attrsOf = elemType: mkOptionType {
       name = "attribute set of ${elemType.name}s";
-      check = x: isAttrs x && all elemType.check (attrValues x);
+      check = isAttrs;
       merge = loc: defs:
-        zipAttrsWith (name: elemType.merge (loc ++ [name]))
+        mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
+          let
+            inherit (mergeDefinitions (loc ++ [name]) elemType defs)
+              defsFinal mergedValue;
+          in if defsFinal == [] then {} else { value = mergedValue; })
           # Push down position info.
           (map (def: listToAttrs (mapAttrsToList (n: def':
-            { name = n; value = { inherit (def) file; value = def'; }; }) def.value)) defs);
+            { name = n; value = { inherit (def) file; value = def'; }; }) def.value)) defs)));
       getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name>"]);
       getSubModules = elemType.getSubModules;
       substSubModules = m: attrsOf (elemType.substSubModules m);