From 2d91012754dbe707fe60a0017496f78076d6694a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 5 Sep 2018 21:22:37 +0200
Subject: [PATCH] fetchurl: Respect unpack

Fixes #2393.
---
 src/libstore/builtins/fetchurl.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/libstore/builtins/fetchurl.cc b/src/libstore/builtins/fetchurl.cc
index b4dcb35f9..92aec63a0 100644
--- a/src/libstore/builtins/fetchurl.cc
+++ b/src/libstore/builtins/fetchurl.cc
@@ -24,6 +24,7 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
 
     Path storePath = getAttr("out");
     auto mainUrl = getAttr("url");
+    bool unpack = get(drv.env, "unpack", "") == "1";
 
     /* Note: have to use a fresh downloader here because we're in
        a forked process. */
@@ -40,12 +41,12 @@ void builtinFetchurl(const BasicDerivation & drv, const std::string & netrcData)
             request.decompress = false;
 
             auto decompressor = makeDecompressionSink(
-                hasSuffix(mainUrl, ".xz") ? "xz" : "none", sink);
+                unpack && hasSuffix(mainUrl, ".xz") ? "xz" : "none", sink);
             downloader->download(std::move(request), *decompressor);
             decompressor->finish();
         });
 
-        if (get(drv.env, "unpack", "") == "1")
+        if (unpack)
             restorePath(storePath, *source);
         else
             writeFile(storePath, *source);