From a93e91ff484005e05491621664ab71f888ad2ba2 Mon Sep 17 00:00:00 2001
From: Ludovic Courtès <ludo@gnu.org>
Date: Fri, 21 Feb 2014 17:37:55 +0100
Subject: nar: 'write-file' can write to non-file ports.

* guix/nar.scm (write-contents): Use 'sendfile' only when P is a file
  port.
* tests/nar.scm ("write-file supports non-file output ports"): New test.
---
 guix/nar.scm  | 3 ++-
 tests/nar.scm | 7 +++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/guix/nar.scm b/guix/nar.scm
index 4bc2deb229..89a71302e0 100644
--- a/guix/nar.scm
+++ b/guix/nar.scm
@@ -112,7 +112,8 @@
   (write-long-long size p)
   (call-with-binary-input-file file
     ;; Use `sendfile' when available (Guile 2.0.8+).
-    (if (compile-time-value (defined? 'sendfile))
+    (if (and (compile-time-value (defined? 'sendfile))
+             (file-port? p))
         (cut sendfile p <> size 0)
         (cut dump <> p size)))
   (write-padding size p))
diff --git a/tests/nar.scm b/tests/nar.scm
index 9f21f990c8..7ae8cf0aa7 100644
--- a/tests/nar.scm
+++ b/tests/nar.scm
@@ -183,6 +183,13 @@
 
 (test-begin "nar")
 
+(test-assert "write-file supports non-file output ports"
+  (let ((input  (string-append (dirname (search-path %load-path "guix.scm"))
+                               "/guix"))
+        (output (%make-void-port "w")))
+    (write-file input output)
+    #t))
+
 (test-assert "write-file + restore-file"
   (let* ((input  (string-append (dirname (search-path %load-path "guix.scm"))
                                 "/guix"))
-- 
cgit 1.4.1