From d5222394923912929e7130939e14b67ad66bfc22 Mon Sep 17 00:00:00 2001
From: Bill Somerville <bill@classdesign.com>
Date: Sat, 22 Aug 2020 11:58:39 +0100
Subject: [PATCH] CMake v3.17 compatability

---
 CMake/Modules/FindFFTW3.cmake | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/CMake/Modules/FindFFTW3.cmake b/CMake/Modules/FindFFTW3.cmake
index 10349cb69..999c2ffe3 100644
--- a/CMake/Modules/FindFFTW3.cmake
+++ b/CMake/Modules/FindFFTW3.cmake
@@ -34,6 +34,12 @@
 #
 # $Id: FindFFTW3.cmake 15918 2010-06-25 11:12:42Z loose $
 
+# Compatibily with old style MinGW packages with no .dll.a files
+# needed since CMake v3.17 because of fix for #20019
+if (MINGW)
+  set (CMAKE_FIND_LIBRARY_SUFFIXES ".dll" ".dll.a" ".a" ".lib")
+endif ()
+
 # Use double precision by default.
 if (FFTW3_FIND_COMPONENTS MATCHES "^$")
   set (_components double)