From d5e64feaddf032f52cd7b96e7d20e0500bf00a1a Mon Sep 17 00:00:00 2001
From: Christoph Junghans <junghans@lanl.gov>
Date: Sat, 12 Aug 2017 10:58:35 -0600
Subject: [PATCH] tweaks for epel7

---
 c99.patch   | 29 +++++++++++++++++++++++++++++
 libaec.spec |  6 ++++--
 2 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 c99.patch

diff --git a/c99.patch b/c99.patch
new file mode 100644
index 0000000..c18cf95
--- /dev/null
+++ b/c99.patch
@@ -0,0 +1,29 @@
+From a3d42317b104f7dc12dd9821293ddd079df352d4 Mon Sep 17 00:00:00 2001
+From: Christoph Junghans <junghans@votca.org>
+Date: Sat, 12 Aug 2017 10:36:24 -0600
+Subject: [PATCH] cmake: require c99 standard
+
+Some files, e.g. encode_accessors.c, use loop initial declarations
+that are only allowed in C99 mode. Newer compilers enable that mode
+automatically, but olders might fail. CMAKE_C_STANDARD got add in
+CMake-3.1, so let's increase the minimal version by 0.1.
+
+Signed-off-by: Christoph Junghans <junghans@votca.org>
+---
+ CMakeLists.txt | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index e8b0e93..22f24e0 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -1,4 +1,5 @@
+-cmake_minimum_required(VERSION 3.0.0)
++cmake_minimum_required(VERSION 3.1)
++set(CMAKE_C_STANDARD 99)
+ include(CheckIncludeFiles)
+ include(TestBigEndian)
+ include(CheckCSourceCompiles)
+-- 
+2.13.0
+
diff --git a/libaec.spec b/libaec.spec
index 6dd1432..99bf9db 100644
--- a/libaec.spec
+++ b/libaec.spec
@@ -5,8 +5,9 @@ Summary:        Adaptive Entropy Coding library
 License:        BSD
 Url:            https://gitlab.dkrz.de/k202009/libaec
 Source:         https://gitlab.dkrz.de/k202009/libaec/repository/archive.tar.gz?ref=v%{version}/%{name}-%{version}.tar.gz
+Patch0:         c99.patch
 
-BuildRequires:  cmake
+BuildRequires:  %{?fedora:cmake >= 3.1}%{?rhel:cmake3 >= 3.1}
 
 %description
 Libaec provides fast loss-less compression of 1 up to 32 bit wide
@@ -33,11 +34,12 @@ Devel files for libaec (Adaptive Entropy Coding library).
 %prep
 %setup -q -T -a 0 -c
 mv %{name}-v%{version}-*/* .
+%patch0 -p1
 
 %build
 mkdir build
 pushd build
-%cmake ..
+%{?fedora:%{cmake}}%{?rhel:%{cmake3}} ..
 %make_build
 popd