From 9825c716add4ee43684e9eb0b1462d8e5b9bc653 Mon Sep 17 00:00:00 2001
From: Brian Fox <bfox@gnu.org>
Date: Tue, 5 Oct 1993 01:29:54 +0000
Subject: [PATCH] If POSIX and HAVE_UNISTD_H are defined, and unistd.h hasn't
 already been included, include it.

---
 src/systty.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/systty.h b/src/systty.h
index 5d651877c95..67bf3bf240d 100644
--- a/src/systty.h
+++ b/src/systty.h
@@ -114,11 +114,18 @@ static struct sensemode {
 #ifdef AIX
 #include <sys/pty.h>
 #include <unistd.h>
+#define UNISTD_H_INCLUDED
 #endif /* AIX */
 
 #ifdef IRIX4
 /* Get _getpty prototype */
 #include <unistd.h>
+#define UNISTD_H_INCLUDED
+#endif
+
+#if defined (POSIX) && !defined (UNISTD_H_INCLUDED) && defined (HAVE_UNISTD_H)
+#include <unistd.h>
+#define UNISTD_H_INCLUDED
 #endif
 
 #ifdef SYSV_PTYS
-- 
2.39.5