www: sort all /$INBOX/ topics by Received: timestamp

Our previous pinning prevention only worked to prevent older
(non-most-recent) topics from being pinned to the landing page,
but not the most recent window of messages.

We still sort messages within threads by Date: because that
makes git-send-email patchsets display more nicely, but we
don't want recent topics pinned due to future Date: headers.

I nearly switched sort_ds() back to sorting by Received: until
I looked back on commit 8e52e5fdea416d6fda0b8d301144af0c043a5a76
(use both Date: and Received: times, 2018-03-21) and was reminded
git-send-email relies on Date: for large series, so I added a
note about it for sort_ds().

Reported-by: Kyle Meyer <kyle@kyleam.com>
Tested-by: Kyle Meyer <kyle@kyleam.com>
Link: https://public-inbox.org/meta/87edr5gx63.fsf@kyleam.com/

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index b8d6d85e77470737d4200718c4771d540dd08618..e5f748f700773b1807bb76aa9aec1716510b7a66 100644 (file)
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -1019,6 +1019,8 @@ sub _skel_ghost {
        1;
 }
 
+# note: we favor Date: here because git-send-email increments it
+# to preserve [PATCH $N/$M] ordering in series (it can't control Received:)
 sub sort_ds {
        @{$_[0]} = sort {
                (eval { $a->topmost->{ds} } || 0) <=>
@@ -1040,9 +1042,10 @@ sub acc_topic { # walk_thread callback
        if ($has_blob) {
                my $subj = subject_normalized($smsg->{subject});
                $subj = '(no subject)' if $subj eq '';
+               my $ts = $smsg->{ts};
                my $ds = $smsg->{ds};
                if ($level == 0) { # new, top-level topic
-                       my $topic = [ $ds, 1, { $subj => $mid }, $subj ];
+                       my $topic = [ $ts, $ds, 1, { $subj => $mid }, $subj ];
                        $ctx->{-cur_topic} = $topic;
                        push @{$ctx->{order}}, $topic;
                        return 1;
@@ -1050,10 +1053,11 @@ sub acc_topic { # walk_thread callback
 
                # continue existing topic
                my $topic = $ctx->{-cur_topic}; # should never be undef
-               $topic->[0] = $ds if $ds > $topic->[0];
-               $topic->[1]++; # bump N+ message counter
-               my $seen = $topic->[2];
-               if (scalar(@$topic) == 3) { # parent was a ghost
+               $topic->[0] = $ts if $ts > $topic->[0];
+               $topic->[1] = $ds if $ds > $topic->[1];
+               $topic->[2]++; # bump N+ message counter
+               my $seen = $topic->[3];
+               if (scalar(@$topic) == 4) { # parent was a ghost
                        push @$topic, $subj;
                } elsif (!defined($seen->{$subj})) {
                        push @$topic, $level, $subj; # @extra messages
@@ -1061,7 +1065,7 @@ sub acc_topic { # walk_thread callback
                $seen->{$subj} = $mid; # latest for subject
        } else { # ghost message
                return 1 if $level != 0; # ignore child ghosts
-               my $topic = $ctx->{-cur_topic} = [ -666, 0, {} ];
+               my $topic = $ctx->{-cur_topic} = [ -666, -666, 0, {} ];
                push @{$ctx->{order}}, $topic;
        }
        1;
@@ -1082,7 +1086,7 @@ sub dump_topics {
        }
        # sort by recency, this allows new posts to "bump" old topics...
        foreach my $topic (sort { $b->[0] <=> $a->[0] } @$order) {
-               my ($ds, $n, $seen, $top_subj, @extra) = @$topic;
+               my ($ts, $ds, $n, $seen, $top_subj, @extra) = @$topic;
                @$topic = ();
                next unless defined $top_subj;  # ghost topic
                my $mid = delete $seen->{$top_subj};