From e42a3db8aafb8bf431024c542a0c884059b97675 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue, 7 Jun 2011 16:01:33 -0700
Subject: [PATCH] stat-time: get_stat_birthtime failure is better-defined
* lib/stat-time.h (get_stat_birthtime): If the time is not available,
return a timestamp whose tv_sec and tv_nsec values are both -1.
Previously, the spec said only that the tv_nsec value was negative.
This upward-compatible change simplifies GNU tar a bit.
---
ChangeLog | 8 ++++++++
lib/stat-time.h | 14 ++++++++------
2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index af211551b5..149049044c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-06-07 Paul Eggert <eggert@cs.ucla.edu>
+
+ stat-time: get_stat_birthtime failure is better-defined
+ * lib/stat-time.h (get_stat_birthtime): If the time is not available,
+ return a timestamp whose tv_sec and tv_nsec values are both -1.
+ Previously, the spec said only that the tv_nsec value was negative.
+ This upward-compatible change simplifies GNU tar a bit.
+
2011-06-07 Eric Blake <eblake@redhat.com>
strerror_r-posix: work around cygwin 1.7.9
diff --git a/lib/stat-time.h b/lib/stat-time.h
index d36a78ec54..86d9d4b8f7 100644
--- a/lib/stat-time.h
+++ b/lib/stat-time.h
@@ -142,7 +142,7 @@ get_stat_mtime (struct stat const *st)
}
/* Return *ST's birth time, if available; otherwise return a value
- with negative tv_nsec. */
+ with tv_sec and tv_nsec both equal to -1. */
static inline struct timespec
get_stat_birthtime (struct stat const *st)
{
@@ -161,7 +161,7 @@ get_stat_birthtime (struct stat const *st)
t.tv_sec = st->st_ctime;
t.tv_nsec = 0;
#else
- /* Birth time is not supported. Set tv_sec to avoid undefined behavior. */
+ /* Birth time is not supported. */
t.tv_sec = -1;
t.tv_nsec = -1;
/* Avoid a "parameter unused" warning. */
@@ -175,10 +175,12 @@ get_stat_birthtime (struct stat const *st)
using zero. Attempt to work around this problem. Alas, this can
report failure even for valid time stamps. Also, NetBSD
sometimes returns junk in the birth time fields; work around this
- bug if it is detected. There's no need to detect negative
- tv_nsec junk as negative tv_nsec already indicates an error. */
- if (t.tv_sec == 0 || 1000000000 <= t.tv_nsec)
- t.tv_nsec = -1;
+ bug if it is detected. */
+ if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
+ {
+ t.tv_sec = -1;
+ t.tv_nsec = -1;
+ }
#endif
return t;
--
2.30.2