[mod_webdav] define _NETBSD_SOURCE on NetBSD
NetBSD dirent.h improperly hides fdopendir() (POSIX.1-2008) declaration
which should be visible w/ _XOPEN_SOURCE 700 or _POSIX_C_SOURCE 200809L
#if !defined(_XOPEN_SOURCE) || _XOPEN_SOURCE-0 < 700
#undef _XOPEN_SOURCE
#define _XOPEN_SOURCE 700
+/* NetBSD dirent.h improperly hides fdopendir() (POSIX.1-2008) declaration
+ * which should be visible with _XOPEN_SOURCE 700 or _POSIX_C_SOURCE 200809L */
+#ifdef __NetBSD__
+#define _NETBSD_SOURCE
+#endif
#endif
/* DT_UNKNOWN DTTOIF() */
#ifndef _GNU_SOURCE
