From 4653160057ceb2a44977c4378b175352409a62a4 Mon Sep 17 00:00:00 2001
From: Joachim Fasting <joachifm@fastmail.fm>
Date: Tue, 13 Sep 2016 01:08:09 +0200
Subject: [PATCH] squashfsTools: optional lz4 support

---
 pkgs/tools/filesystems/squashfs/default.nix | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/pkgs/tools/filesystems/squashfs/default.nix b/pkgs/tools/filesystems/squashfs/default.nix
index c43eb0599761..a2fc5bc3d40b 100644
--- a/pkgs/tools/filesystems/squashfs/default.nix
+++ b/pkgs/tools/filesystems/squashfs/default.nix
@@ -1,4 +1,9 @@
-{ stdenv, fetchFromGitHub, zlib, xz }:
+{ stdenv, fetchFromGitHub, zlib, xz
+, lz4 ? null
+, lz4Support ? false
+}:
+
+assert lz4Support -> (lz4 != null);
 
 stdenv.mkDerivation rec {
   name = "squashfs-4.4dev";
@@ -10,13 +15,15 @@ stdenv.mkDerivation rec {
     rev = "9c1db6d13a51a2e009f0027ef336ce03624eac0d";
   };
 
-  buildInputs = [ zlib xz ];
+  buildInputs = [ zlib xz ]
+    ++ stdenv.lib.optional lz4Support lz4;
 
   preBuild = "cd squashfs-tools";
 
   installFlags = "INSTALL_DIR=\${out}/bin";
 
-  makeFlags = "XZ_SUPPORT=1";
+  makeFlags = [ "XZ_SUPPORT=1" ]
+    ++ stdenv.lib.optional lz4Support "LZ4_SUPPORT=1";
 
   meta = {
     homepage = http://squashfs.sourceforge.net/;