Don't redefine isnan() macro if MinGW already defined one.

diff --git a/win32/win32.h b/win32/win32.h
index 3916b2e..762ab54 100644 (file)
--- a/win32/win32.h
+++ b/win32/win32.h
@@ -260,7 +260,9 @@ typedef long                gid_t;
 #endif
 #define flushall       _flushall
 #define fcloseall      _fcloseall
+#ifndef isnan
 #define isnan          _isnan  /* ...same libraries as MSVC */
+#endif
 
 #ifndef _O_NOINHERIT
 #  define _O_NOINHERIT 0x0080