[PATCH 2/7] nntp: support YYYYMMDD dates for commands

[Eric Wong <e@80x24.org>]

RFC 3977 supports YYYYMMDD dates while retaining backwards
compatibility for old YYMMDD dates.
---
 lib/PublicInbox/NNTP.pm | 18 +++++++++++-------
 t/nntp.t                | 29 +++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 91b10f2..bc8d6ed 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -169,22 +169,26 @@ sub cmd_listgroup ($;$) {
 sub parse_time ($$;$) {
 	my ($date, $time, $gmt) = @_;
 	use Time::Local qw();
-	my ($YY, $MM, $DD) = unpack('A2A2A2', $date);
 	my ($hh, $mm, $ss) = unpack('A2A2A2', $time);
 	if (defined $gmt) {
 		$gmt =~ /\A(?:UTC|GMT)\z/i or die "GM invalid: $gmt\n";
 		$gmt = 1;
 	}
 	my @now = $gmt ? gmtime : localtime;
-	if ($YY > strftime('%y', @now)) {
-		my $cur_year = $now[5] + 1900;
-		$YY += int($cur_year / 1000) * 1000 - 100;
+	my ($YYYY, $MM, $DD);
+	if (length($date) == 8) { # RFC 3977 allows YYYYMMDD
+		($YYYY, $MM, $DD) = unpack('A4A2A2', $date);
+	} else { # legacy clients send YYMMDD
+		($YYYY, $MM, $DD) = unpack('A2A2A2', $date);
+		if ($YYYY > strftime('%y', @now)) {
+			my $cur_year = $now[5] + 1900;
+			$YYYY += int($cur_year / 1000) * 1000 - 100;
+		}
 	}
-
 	if ($gmt) {
-		Time::Local::timegm($ss, $mm, $hh, $DD, $MM - 1, $YY);
+		Time::Local::timegm($ss, $mm, $hh, $DD, $MM - 1, $YYYY);
 	} else {
-		Time::Local::timelocal($ss, $mm, $hh, $DD, $MM - 1, $YY);
+		Time::Local::timelocal($ss, $mm, $hh, $DD, $MM - 1, $YYYY);
 	}
 }
 
diff --git a/t/nntp.t b/t/nntp.t
index 82918ff..c917888 100644
--- a/t/nntp.t
+++ b/t/nntp.t
@@ -61,4 +61,33 @@ use_ok 'PublicInbox::NNTP';
 	ngpat_like('a.s.r', 'a.t,a.s.*');
 }
 
+{
+	use POSIX qw(strftime);
+	sub time_roundtrip {
+		my ($date, $time, $gmt) = @_;
+		my $m = join(' ', @_);
+		my $ts = PublicInbox::NNTP::parse_time(@_);
+		my @t = gmtime($ts);
+		my ($d, $t);
+		if (length($date) == 8) {
+			($d, $t) = split(' ', strftime('%Y%m%d %H%M%S', @t));
+		} else {
+			($d, $t) = split(' ', strftime('%g%m%d %H%M%S', @t));
+		}
+		is_deeply([$d, $t], [$date, $time], "roundtripped: $m");
+		$ts;
+	}
+	my $x1 = time_roundtrip(qw(20141109 060606 GMT));
+	my $x2 = time_roundtrip(qw(141109 060606 GMT));
+	my $x3 = time_roundtrip(qw(930724 060606 GMT));
+
+	SKIP: {
+		skip('YYMMDD test needs updating', 2) if (time > 0x7fffffff);
+		# our world probably ends in 2038, but if not we'll try to
+		# remember to update the test then
+		is($x1, $x2, 'YYYYMMDD and YYMMDD parse identically');
+		is(strftime('%Y', gmtime($x3)), '1993', '930724 was in 1993');
+	}
+}
+
 done_testing();
-- 
EW