From a40e06ee336d608cfe0928d91d2b44112d8fd1e2 Mon Sep 17 00:00:00 2001 From: "Bernhard M. Wiedemann" Date: Fri, 23 Feb 2018 18:20:45 +0100 Subject: [PATCH] perl: call timegm and timelocal with 4-digit year Amazingly, timegm(gmtime(0)) is only 0 before 2020 because perl's timegm deviates from GNU timegm(3) in how it handles years. man Time::Local says Whenever possible, use an absolute four digit year instead. with a detailed explanation about ambiguity of 2-digit years above that. Even though this ambiguity is error-prone with >50% of users getting it wrong, it has been like this for 20+ years, so we just use 4-digit years everywhere to be on the safe side. We add some extra logic to cvsimport because it allows 2-digit year input and interpreting an 18 as 1918 can be avoided easily and safely. Signed-off-by: Bernhard M. Wiedemann Signed-off-by: Junio C Hamano --- contrib/examples/git-svnimport.perl | 2 +- git-cvsimport.perl | 4 +++- perl/Git.pm | 4 +++- perl/Git/SVN.pm | 2 +- 4 files changed, 8 insertions(+), 4 deletions(-) diff --git a/contrib/examples/git-svnimport.perl b/contrib/examples/git-svnimport.perl index c414f0d9c7..75a43e23b6 100755 --- a/contrib/examples/git-svnimport.perl +++ b/contrib/examples/git-svnimport.perl @@ -238,7 +238,7 @@ sub pdate($) { my($d) = @_; $d =~ m#(\d\d\d\d)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)# or die "Unparseable date: $d\n"; - my $y=$1; $y-=1900 if $y>1900; + my $y=$1; $y+=1900 if $y<1000; return timegm($6||0,$5,$4,$3,$2-1,$y); } diff --git a/git-cvsimport.perl b/git-cvsimport.perl index 2d8df83172..b31613cb8a 100755 --- a/git-cvsimport.perl +++ b/git-cvsimport.perl @@ -601,7 +601,9 @@ sub pdate($) { my ($d) = @_; m#(\d{2,4})/(\d\d)/(\d\d)\s(\d\d):(\d\d)(?::(\d\d))?# or die "Unparseable date: $d\n"; - my $y=$1; $y-=1900 if $y>1900; + my $y=$1; + $y+=100 if $y<70; + $y+=1900 if $y<1000; return timegm($6||0,$5,$4,$3,$2-1,$y); } diff --git a/perl/Git.pm b/perl/Git.pm index ffa09ace92..df62518c71 100644 --- a/perl/Git.pm +++ b/perl/Git.pm @@ -534,7 +534,9 @@ If TIME is not supplied, the current local time is used. sub get_tz_offset { # some systems don't handle or mishandle %z, so be creative. my $t = shift || time; - my $gm = timegm(localtime($t)); + my @t = localtime($t); + $t[5] += 1900; + my $gm = timegm(@t); my $sign = qw( + + - )[ $gm <=> $t ]; return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]); } diff --git a/perl/Git/SVN.pm b/perl/Git/SVN.pm index bc4eed3d75..991a5885e9 100644 --- a/perl/Git/SVN.pm +++ b/perl/Git/SVN.pm @@ -1405,7 +1405,7 @@ sub parse_svn_date { $ENV{TZ} = 'UTC'; my $epoch_in_UTC = - Time::Local::timelocal($S, $M, $H, $d, $m - 1, $Y - 1900); + Time::Local::timelocal($S, $M, $H, $d, $m - 1, $Y); # Determine our local timezone (including DST) at the # time of $epoch_in_UTC. $Git::SVN::Log::TZ stored the -- 2.39.2