--- a/a/nss/lib/zlib/gzguts.h	2010-08-22 03:07:03.000000000 +0200
+++ b/b/nss/lib/zlib/gzguts.h	2012-07-17 08:52:14.821552788 +0200
@@ -26,6 +26,9 @@
 #  include <limits.h>
 #endif
 #include <fcntl.h>
+#ifndef _WIN32
+#include <unistd.h>
+#endif
 
 #ifdef NO_DEFLATE       /* for compatibility with old definition */
 #  define NO_GZCOMPRESS