From e6e683731def0d2a16b2109ad95a67bf756edfba Mon Sep 17 00:00:00 2001
From: Jose Santiago <jsantiago@haivision.com>
Date: Thu, 15 Apr 2021 13:43:55 -0500
Subject: [PATCH] Fix MINGW with pthread cv

ZeroMQ works and MINGW and pthread conditional variables if pthread
mutexes are used. POSIX conditional variables require POSIX mutexes, but
ZeroMQ unconditionally uses WIN32 critital sections even when configured
with pthread conditional variables. This of course does not work. This
patch fixes the build so that MINGW builds do not use WIN32 critical
sections and instead use POSIX mutexes when configured with pthread
conditional variables.

Tested with:

```
 CC=x86_64-w64-mingw32-gcc CXX=x86_64-w64-mingw32-g++ ../libzmq/configure --host=x86_64-w64-mingw32 --prefix=`pwd`/stage --enable-debug --disable-Werror --enable-libunwind=no   --with-cv-impl=pthread --enable-libbsd=no
```

```
x86_64-w64-mingw32-gcc --version

   x86_64-w64-mingw32-gcc (GCC) 10.2.0.....
```
---
 src/mutex.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mutex.hpp b/src/mutex.hpp
index 8ff02269..25ad8451 100644
--- a/src/mutex.hpp
+++ b/src/mutex.hpp
@@ -35,7 +35,7 @@
 
 //  Mutex class encapsulates OS mutex in a platform-independent way.
 
-#ifdef ZMQ_HAVE_WINDOWS
+#if defined(ZMQ_HAVE_WINDOWS) && !defined(ZMQ_USE_CV_IMPL_PTHREADS)
 
 #include "windows.hpp"