libarchive: fix autoconf lzma_stream_encoder_mt detection properly.

https://github.com/libarchive/libarchive/pull/700

srcpkgs/libarchive/patches/0001-configure.ac-define-HAVE_LZMA_STREAM_ENCODER_MT-if-i.patch

@@ -0,0 +1,29 @@
+From 9690ea4f3b79d07860f3ea55b6fab571721849b5 Mon Sep 17 00:00:00 2001
+From: Juan RP <xtraeme@voidlinux.eu>
+Date: Thu, 5 May 2016 07:55:57 +0200
+Subject: [PATCH] configure.ac: define HAVE_LZMA_STREAM_ENCODER_MT if it is
+ detected properly.
+
+... otherwise HAVE_LZMA_STREAM_ENCODER_MT is undefined and the code
+for multithreaded xz compression is skipped completely.
+---
+ configure.ac | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/configure.ac b/configure.ac
+index 1ab54cb..cb6943f 100644
+--- configure.ac
++++ configure.ac
+@@ -377,6 +377,9 @@ if test "x$with_lzma" != "xno"; then
+       AC_LANG_PROGRAM([[#include <lzma.h>]],
+                       [[lzma_stream_encoder_mt(0, 0);]])],
+       [ac_cv_lzma_has_mt=yes], [ac_cv_lzma_has_mt=no])])
++  if test "x$ac_cv_lzma_has_mt" != xno; then
++	  AC_DEFINE([HAVE_LZMA_STREAM_ENCODER_MT], [1], [Define to 1 if you have the `lzma_stream_encoder_mt' function.])
++  fi
+ fi
+ 
+ AC_ARG_WITH([lzo2],
+-- 
+2.8.2
+

srcpkgs/libarchive/template

@@ -1,12 +1,13 @@
 # Template file for 'libarchive'
 pkgname=libarchive
 version=3.2.0
-revision=4
+revision=5
 bootstrap=yes
 build_style=gnu-configure
 configure_args="$(vopt_enable acl) $(vopt_enable acl xattr)
  $(vopt_with expat) $(vopt_with lzo lzo2) $(vopt_with ssl openssl)
  --without-xml2 --without-nettle --disable-rpath ac_cv_func_lchmod=no"
+hostmakedepends="automake libtool pkg-config"
 makedepends="zlib-devel bzip2-devel liblzma-devel
  $(vopt_if acl acl-devel) $(vopt_if expat expat-devel)
  $(vopt_if lzo lzo-devel) $(vopt_if ssl libressl-devel)"
@@ -17,15 +18,9 @@ license="BSD"
 distfiles="http://www.libarchive.org/downloads/libarchive-${version}.tar.gz"
 checksum=7bce45fd71ff01dc20d19edd78322d4965583d81b8bed8e26cacb65d6f5baa87
 
-# XXX wtf, configure.ac does not set this!
-CFLAGS="-DHAVE_LZMA_STREAM_ENCODER_MT"
-
-if [ "$CROSS_BUILD" ]; then
-	hostmakedepends="automake libtool pkg-config"
-	pre_configure() {
-		autoreconf -if
-	}
-fi
+pre_configure() {
+	autoreconf -if
+}
 
 # Package build options
 build_options="acl expat lzo ssl"