From 79e712822fcfe797c545e2db5bcef9a07b00b2e5 Mon Sep 17 00:00:00 2001
From: aszlig <aszlig@redmoonstudios.org>
Date: Mon, 24 Apr 2017 12:02:10 +0200
Subject: [PATCH] nixos/xserver: Document xrandrHeads.apply

It was asked by @CMCDragonkai to elaborate on that, so let's just do
this by actually providing a code comment.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
---
 nixos/modules/services/x11/xserver.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/nixos/modules/services/x11/xserver.nix b/nixos/modules/services/x11/xserver.nix
index 9ac69195a67..20028d7eb6a 100644
--- a/nixos/modules/services/x11/xserver.nix
+++ b/nixos/modules/services/x11/xserver.nix
@@ -374,6 +374,8 @@ in
         type = with types; listOf (coercedTo str (output: {
           inherit output;
         }) (submodule { options = xrandrOptions; }));
+        # Set primary to true for the first head if no other has been set
+        # primary already.
         apply = heads: let
           hasPrimary = any (x: x.primary) heads;
           firstPrimary = head heads // { primary = true; };