From 2047eb360de5a9d2a8cac6a689bd7846c5a0128f Mon Sep 17 00:00:00 2001
From: Christian Pfeiffer <cpfeiffer@live.de>
Date: Tue, 5 Dec 2017 12:31:56 +0100
Subject: [PATCH] FindMPI: Fix multiple configure runs

Due to a erroneous logical dependency on a temporary variable, FindMPI
would depend its FOUND status on the set of flags needed to support
compiler-implicit MPI support after the first configure run.

This behavior is especially causing a misreported NOT FOUND status after
the first run on MPI implementations without MPI compiler like MS-MPI or
MPICH2 on Windows.
---
 Modules/FindMPI.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/FindMPI.cmake b/Modules/FindMPI.cmake
index 7f4c44c5e0..2af032922d 100644
--- a/Modules/FindMPI.cmake
+++ b/Modules/FindMPI.cmake
@@ -1336,7 +1336,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
     set(MPI_${LANG}_FIND_VERSION_EXACT ${MPI_FIND_VERSION_EXACT})
 
     unset(MPI_${LANG}_REQUIRED_VARS)
-    if (MPI_${LANG}_WRAPPER_FOUND OR MPI_${LANG}_GUESS_FOUND)
+    if (NOT "${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}")
       foreach(mpilibname IN LISTS MPI_${LANG}_LIB_NAMES)
         list(APPEND MPI_${LANG}_REQUIRED_VARS "MPI_${mpilibname}_LIBRARY")
       endforeach()