[PATCH] view: correctly pick latest in index anchor links

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

The last message in a thread _display_ is not necessarily the
latest message in the thread.  We must go by the Date: header
on the messages themselves as a best-guess.  Of course Date:
headers may lie, but most mail clients trust them by default,
so we will, too.
---
 lib/PublicInbox/View.pm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 07023e8..ccdcde2 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -823,7 +823,10 @@ sub add_topic {
 
 		my $u = $x->header('X-PI-From');
 		my $ts = $x->header('X-PI-TS');
-		$state->{latest}->{$topic} = [ $mid, $u, $ts ];
+		my $exist = $state->{latest}->{$topic};
+		if (!$exist || $exist->[2] < $ts) {
+			$state->{latest}->{$topic} = [ $mid, $u, $ts ];
+		}
 	} else {
 		# ghost message, do not bump level
 		$child_adjust = 0;
-- 
EW