From 1dce7ffdb655772595c59aa1fa6a4b237a2f06be Mon Sep 17 00:00:00 2001
From: Ian Kirker <ian.kirker@gmail.com>
Date: Wed, 22 Nov 2017 20:13:53 +0000
Subject: [PATCH] Hardens test for MPI

Previously, the configure script could fail to find an MPI
implementation but continue regardless. This alters the behaviour so
that the configure script fails if the check for MPI does.
---
 configure.ac | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 604677c..3513c12 100755
--- a/configure.ac
+++ b/configure.ac
@@ -18,8 +18,12 @@ AC_CANONICAL_HOST
 AM_INIT_AUTOMAKE([check-news dist-bzip2 gnu no-define])
 AM_MAINTAINER_MODE
 
-# Checks for programs.
-AX_PROG_CC_MPI
+# Checks for programs
+
+# We can't do anything without a working MPI
+AX_PROG_CC_MPI(,,[
+    AC_MSG_FAILURE([MPI compiler requested, but couldn't use MPI.])
+])
 
 # No reason not to require modern C at this point
 AC_PROG_CC_C99