Fix warnings on Windows.

macdice · macdice · commit bde60daa0ec9 · 2022-07-20T16:09:50.000+12:00
Avoid macro redefinition warnings. Reported-by: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/CAApHDvocHp4SXcPeMTwFiCQGaf9JypjTJ3Bh90jcPuGwxyDjjQ%40mail.gmail.com
diff --git a/src/include/port/win32_port.h b/src/include/port/win32_port.h
@@ -87,7 +87,9 @@
  * We have a replacement for fdatasync() in src/port/fdatasync.c, which is
  * unconditionally used by MSVC and Mingw builds.
  */
+#ifndef HAVE_FDATASYNC
 #define HAVE_FDATASYNC
+#endif
 
 #define USES_WINSOCK
 
