From e300a0f8d25cb309aa3fe9d1d78f6db74b625902 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Thu, 11 Oct 2012 00:32:17 +0200
Subject: [PATCH] distro: Add missing bits from previous commit.

* distro/packages/base.scm (default-keyword-arguments): New procedure.
---
 distro/packages/base.scm | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/distro/packages/base.scm b/distro/packages/base.scm
index f2a93f8601..2fb67b62af 100644
--- a/distro/packages/base.scm
+++ b/distro/packages/base.scm
@@ -1388,6 +1388,20 @@ with the Linux kernel.")
   ;; The Guile used to run the build scripts of the initial derivations.
   (nixpkgs-derivation* "guile"))
 
+(define (default-keyword-arguments args defaults)
+  "Return ARGS augmented with any keyword/value from DEFAULTS for
+keywords not already present in ARGS."
+  (let loop ((defaults defaults)
+             (args     args))
+    (match defaults
+      ((kw value rest ...)
+       (loop rest
+             (if (assoc-ref kw args)
+                 args
+                 (cons* kw value args))))
+      (()
+       args))))
+
 (define-syntax substitute-keyword-arguments
   (syntax-rules ()
     "Return a new list of arguments where the value for keyword arg KW is