CVS commit: src/usr.bin/touch

["Robert Elz" <kre%netbsd.org@localhost>]

Module Name:    src
Committed By:   kre
Date:           Thu Feb  8 02:54:07 UTC 2024

Modified Files:
        src/usr.bin/touch: touch.c

Log Message:
Check that mktime() (or timegm() the one time it is used) do not
alter any of the material fields of the struct tm that was handed
to it.   If any were altered, then the time string passed in was
not a valid time representation, and so should be rejected.

This one is not an invisible change, it prevents use of things like
"-t 202402300000"  (which previously would have been interpreted as
"-t 202403010000" - the day after the 29th of Feb in 2024).

I believe this is an improvement however, and in line with the
general intent that if you specify a date and time, that exact
date and time is what touch should be using.   It does mean that
specifying "60" for the seconds field is almost guaranteed to
fail on any POSIX system, as leap seconds simply don't exist
there (on a non-POSIX-conforming system that uses leap seconds,
the :60 should work, if specified with the correct date and time
at which the leap second actually occurs).

The one exception is when parsedate(3) is used, as that does not
do this check (which allows things like "-1 day" on the 1st of
a month to work).

(This is the last of this sequence of updates to touch.c, an
update to touch.1 follows).


To generate a diff of this commit:
cvs rdiff -u -r1.37 -r1.38 src/usr.bin/touch/touch.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.