From e8b7619433a6d6e6ff8f106850a3f1d2808653fb Mon Sep 17 00:00:00 2001
From: Brent Cook <bcook@openbsd.org>
Date: Mon, 21 Dec 2015 05:53:20 -0600
Subject: [PATCH 12/12] check result of ftello/ftruncate

---
 src/usr.sbin/ntpd/ntpd.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/usr.sbin/ntpd/ntpd.c b/src/usr.sbin/ntpd/ntpd.c
index af8700e..631e4de 100644
--- a/src/usr.sbin/ntpd/ntpd.c
+++ b/src/usr.sbin/ntpd/ntpd.c
@@ -598,6 +598,7 @@ writefreq(double d)
 {
 	int r;
 	static int warnonce = 1;
+        int off;
 
 	if (freqfp == NULL)
 		return 0;
@@ -611,8 +612,10 @@ writefreq(double d)
 		clearerr(freqfp);
 		return 0;
 	}
-	ftruncate(fileno(freqfp), ftello(freqfp));
-	fsync(fileno(freqfp));
+        off = ftello(freqfp);
+        if (off == -1 || ftruncate(fileno(freqfp), off) == -1)
+                log_warnx("can't truncate %s", DRIFTFILE);
+        fsync(fileno(freqfp));
 	return 1;
 }
 
-- 
2.7.0