From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Tue, 10 Jan 2017 16:23:47 +0000 (+0100)
Subject: util: handle zero in conversion of NTP timestamps
X-Git-Tag: 3.0~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b0f7efd59ea793e4eaf8b8ebe909a34d9282de2a;p=thirdparty%2Fchrony.git

util: handle zero in conversion of NTP timestamps

Handle zero NTP timestamp in UTI_Ntp64ToTimespec() as a special value to
make it symmetric with UTI_TimespecToNtp64(). This is needed since
commit d75f6830f190037421a66754849571fd0b495e35, in which a timestamp is
converted back and forth without checking for zero.

It also makes zero NTP timestamps more apparent in debug output.
---

diff --git a/util.c b/util.c
index 0488f010..977580a6 100644
--- a/util.c
+++ b/util.c
@@ -754,8 +754,11 @@ UTI_Ntp64ToTimespec(NTP_int64 *src, struct timespec *dest)
 {
   uint32_t ntp_sec, ntp_frac;
 
-  /* As yet, there is no need to check for zero - all processing that
-     has to detect that case is in the NTP layer */
+  /* Zero is a special value */
+  if (UTI_IsZeroNtp64(src)) {
+    UTI_ZeroTimespec(dest);
+    return;
+  }
 
   ntp_sec = ntohl(src->hi);
   ntp_frac = ntohl(src->lo);