git: 30cfb3c8ee3d - main - ctime.3: Add a note about a possible return value of localtime(3)

From: Gordon Bergling <gbe_at_FreeBSD.org>
Date: Fri, 16 Sep 2022 18:40:57 UTC
The branch main has been updated by gbe (doc committer):

URL: https://cgit.FreeBSD.org/src/commit/?id=30cfb3c8ee3d3fc79644541207c81d20c72176ce

commit 30cfb3c8ee3d3fc79644541207c81d20c72176ce
Author:     Gordon Bergling <gbe@FreeBSD.org>
AuthorDate: 2022-09-16 18:38:58 +0000
Commit:     Gordon Bergling <gbe@FreeBSD.org>
CommitDate: 2022-09-16 18:38:58 +0000

    ctime.3: Add a note about a possible return value of localtime(3)
    
    The localtime(3) function returns a NULL pointer, if the passed in-time
    translates to a year that will not fit in an integer type. It is stricly
    recommended to check the return value to avoid garage output.
    
    Reported by:            mckusick
    Reviewed by:            mckusick, imp, rpokala
    MFC after:              1 week
    Differential Revision:  https://reviews.freebsd.org/D36515
---
 contrib/tzcode/stdtime/ctime.3 | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/contrib/tzcode/stdtime/ctime.3 b/contrib/tzcode/stdtime/ctime.3
index 771027fa62ec..de3a57bab59e 100644
--- a/contrib/tzcode/stdtime/ctime.3
+++ b/contrib/tzcode/stdtime/ctime.3
@@ -30,7 +30,7 @@
 .\"     From: @(#)ctime.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd March 4, 2022
+.Dd September 16, 2022
 .Dt CTIME 3
 .Os
 .Sh NAME
@@ -94,6 +94,10 @@ and returns a pointer to a
 (described below) which contains
 the broken-out time information for the value after adjusting for the current
 time zone (and any other factors such as Daylight Saving Time).
+When the specified time translates to a year that will not fit in an
+.Dv int ,
+.Fn localtime
+returns NULL.
 Time zone adjustments are performed as specified by the
 .Ev TZ
 environment variable (see