X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FView.pm;h=d906276a63e8f27e49c45d64a7eff3fcbe8c73d5;hb=dfef0d2c34fbf21d665c40b5ad5069e9113c35c8;hp=5f9ecd108aacf444b1ad07a46bfd2b356865ecf8;hpb=af4959d5148b60b2549712b5955fd66d71e9a63a;p=public-inbox.git

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 5f9ecd10..60fc1df1 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -1,493 +1,712 @@
-# Copyright (C) 2014-2015 all contributors <meta@public-inbox.org>
-# License: AGPLv3 or later (https://www.gnu.org/licenses/agpl-3.0.txt)
+# Copyright (C) 2014-2018 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 #
 # Used for displaying the HTML web interface.
 # See Documentation/design_www.txt for this.
 package PublicInbox::View;
 use strict;
 use warnings;
-use URI::Escape qw/uri_escape_utf8/;
-use Date::Parse qw/str2time/;
-use Encode qw/find_encoding/;
-use Encode::MIME::Header;
-use Email::MIME::ContentType qw/parse_content_type/;
-use PublicInbox::Hval qw/ascii_html/;
+use PublicInbox::MsgTime qw(msg_datestamp);
+use PublicInbox::Hval qw/ascii_html obfuscate_addrs/;
 use PublicInbox::Linkify;
-use PublicInbox::MID qw/mid_clean id_compress mid2path mid_mime/;
+use PublicInbox::MID qw/id_compress mid_escape mids references/;
+use PublicInbox::MsgIter;
+use PublicInbox::Address;
+use PublicInbox::WwwStream;
+use PublicInbox::Reply;
 require POSIX;
 
-# TODO: make these constants tunable
-use constant MAX_INLINE_QUOTED => 12; # half an 80x24 terminal
-use constant MAX_TRUNC_LEN => 72;
-use constant T_ANCHOR => '#u';
 use constant INDENT => '  ';
+use constant TCHILD => '` ';
+sub th_pfx ($) { $_[0] == 0 ? '' : TCHILD };
 
-my $enc_utf8 = find_encoding('UTF-8');
+# public functions: (unstable)
 
-# public functions:
 sub msg_html {
-	my ($ctx, $mime, $full_pfx, $footer) = @_;
-	$footer = defined($footer) ? "\n$footer" : '';
+	my ($ctx, $mime, $more, $smsg) = @_;
 	my $hdr = $mime->header_obj;
-	headers_to_html_header($hdr, $full_pfx, $ctx) .
-		multipart_text_as_html($mime, $full_pfx) .
-		'</pre><hr /><pre>' .
-		html_footer($hdr, 1, $full_pfx, $ctx) .
-		$footer .
-		'</pre></body></html>';
+	my $ibx = $ctx->{-inbox};
+	my $obfs_ibx = $ctx->{-obfs_ibx} = $ibx->{obfuscate} ? $ibx : undef;
+	my $tip = _msg_html_prepare($hdr, $ctx, $more, 0);
+	my $end = 2;
+	PublicInbox::WwwStream->response($ctx, 200, sub {
+		my ($nr, undef) = @_;
+		if ($nr == 1) {
+			# $more cannot be true w/o $smsg being defined:
+			my $upfx = $more ? '../'.mid_escape($smsg->mid).'/' : '';
+			$tip . multipart_text_as_html($mime, $upfx, $obfs_ibx) .
+				'</pre><hr>'
+		} elsif ($more && @$more) {
+			++$end;
+			msg_html_more($ctx, $more, $nr);
+		} elsif ($nr == $end) {
+			# fake an EOF if generating the footer fails;
+			# we want to at least show the message if something
+			# here crashes:
+			eval {
+				'<pre>' . html_footer($hdr, 1, $ctx) .
+				'</pre>' . msg_reply($ctx, $hdr)
+			};
+		} else {
+			undef
+		}
+	});
+}
+
+sub msg_page {
+	my ($ctx) = @_;
+	my $mid = $ctx->{mid};
+	my $ibx = $ctx->{-inbox};
+	my ($first, $more, $head, $tail, $db);
+	my $smsg;
+	if (my $srch = $ibx->search) {
+		$srch->retry_reopen(sub {
+			($head, $tail, $db) = $srch->each_smsg_by_mid($mid);
+			for (; !defined($first) && $head != $tail; $head++) {
+				my @args = ($head, $db, $mid);
+				$smsg = PublicInbox::SearchMsg->get(@args);
+				$first = $ibx->msg_by_smsg($smsg);
+			}
+			if ($head != $tail) {
+				$more = [ $head, $tail, $db ];
+			}
+		});
+		return unless $first;
+	} else {
+		$first = $ibx->msg_by_mid($mid) or return;
+	}
+	msg_html($ctx, PublicInbox::MIME->new($first), $more, $smsg);
+}
+
+sub msg_html_more {
+	my ($ctx, $more, $nr) = @_;
+	my $str = eval {
+		my $smsg;
+		my ($head, $tail, $db) = @$more;
+		my $mid = $ctx->{mid};
+		for (; !defined($smsg) && $head != $tail; $head++) {
+			my $m = PublicInbox::SearchMsg->get($head, $db, $mid);
+			$smsg = $ctx->{-inbox}->smsg_mime($m);
+		}
+		if ($head == $tail) { # done
+			@$more = ();
+		} else {
+			$more->[0] = $head;
+		}
+		if ($smsg) {
+			my $mime = $smsg->{mime};
+			my $upfx = '../' . mid_escape($smsg->mid) . '/';
+			_msg_html_prepare($mime->header_obj, $ctx, $more, $nr) .
+				multipart_text_as_html($mime, $upfx,
+							$ctx->{-obfs_ibx}) .
+				'</pre><hr>'
+		} else {
+			'';
+		}
+	};
+	if ($@) {
+		warn "Error lookup up additional messages: $@\n";
+		$str = '<pre>Error looking up additional messages</pre>';
+	}
+	$str;
 }
 
-# /$LISTNAME/$MESSAGE_ID/R/
+# /$INBOX/$MESSAGE_ID/#R
 sub msg_reply {
-	my ($ctx, $hdr, $footer) = @_;
-	my $s = $hdr->header('Subject');
-	$s = '(no subject)' if (!defined $s) || ($s eq '');
-	my $f = $hdr->header('From');
-	$f = '' unless defined $f;
-	my $mid = $hdr->header_raw('Message-ID');
-	$mid = PublicInbox::Hval->new_msgid($mid);
-	my $t = ascii_html($s);
+	my ($ctx, $hdr) = @_;
 	my $se_url =
 	 'https://kernel.org/pub/software/scm/git/docs/git-send-email.html';
+	my $p_url =
+	 'https://en.wikipedia.org/wiki/Posting_style#Interleaved_style';
+
+	my $info = '';
+	my $ibx = $ctx->{-inbox};
+	if (my $url = $ibx->{infourl}) {
+		$url = PublicInbox::Hval::prurl($ctx->{env}, $url);
+		$info = qq(\n  List information: <a\nhref="$url">$url</a>\n);
+	}
 
-	my ($arg, $link) = mailto_arg_link($hdr);
-	push @$arg, '/path/to/YOUR_REPLY';
+	my ($arg, $link, $reply_to_all) =
+			PublicInbox::Reply::mailto_arg_link($ibx, $hdr);
+
+	# mailto: link only works if address obfuscation is disabled
+	if ($link) {
+		$link = <<EOF;
 
-	"<html><head><title>replying to \"$t\"</title></head><body><pre>" .
-	"replying to message:\n\n" .
-	"Subject: <b>$t</b>\n" .
-	"From: ". ascii_html($f) .
-	"\nDate: " .  ascii_html($hdr->header('Date')) .
-	"\nMessage-ID: &lt;" . $mid->as_html . "&gt;\n\n" .
-	"There are multiple ways to reply:\n\n" .
-	"* Save the following mbox file, import it into your mail client,\n" .
-	"  and reply-to-all from there: <a\nhref=../raw>mbox</a>\n\n" .
-	"* Reply to all the recipients using the <b>--to</b>, <b>--cc</b>,\n" .
-	"  and <b>--in-reply-to</b> switches of git-send-email(1):\n\n" .
-	"\tgit send-email \\\n\t\t" .
-	join(" \\ \n\t\t", @$arg ). "\n\n" .
-	qq(  <a\nhref="$se_url">$se_url</a>\n\n) .
-	"* If your mail client supports setting the <b>In-Reply-To</b>" .
-	" header\n  via mailto: links, try the " .
-	qq(<a\nhref="$link">mailto: link</a>\n) .
-	"\nFor context, the original <a\nhref=../>message</a> or " .
-	qq(<a\nhref="../t/#u">thread</a>) .
-	'</pre><hr /><pre>' . $footer .  '</pre></body></html>';
-}
-
-sub feed_entry {
-	my ($class, $mime, $full_pfx) = @_;
-
-	# no <head> here for <style>...
-	PublicInbox::Hval::PRE .
-		multipart_text_as_html($mime, $full_pfx) . '</pre>';
+* If your mail client supports setting the <b>In-Reply-To</b> header
+  via mailto: links, try the <a
+href="$link">mailto: link</a>
+EOF
+	}
+
+	push @$arg, '/path/to/YOUR_REPLY';
+	$arg = ascii_html(join(" \\\n    ", '', @$arg));
+	<<EOF
+<hr><pre
+id=R><b>Reply instructions:</b>
+
+You may reply publically to <a
+href=#t>this message</a> via plain-text email
+using any one of the following methods:
+
+* Save the following mbox file, import it into your mail client,
+  and $reply_to_all from there: <a
+href=raw>mbox</a>
+
+  Avoid top-posting and favor interleaved quoting:
+  <a
+href="$p_url">$p_url</a>
+$info
+* Reply using the <b>--to</b>, <b>--cc</b>, and <b>--in-reply-to</b>
+  switches of git-send-email(1):
+
+  git send-email$arg
+
+  <a
+href="$se_url">$se_url</a>
+$link</pre>
+EOF
 }
 
 sub in_reply_to {
 	my ($hdr) = @_;
-	my $irt = $hdr->header_raw('In-Reply-To');
+	my $refs = references($hdr);
+	$refs->[-1];
+}
 
-	return mid_clean($irt) if (defined $irt);
+sub _hdr_names_html ($$) {
+	my ($hdr, $field) = @_;
+	my $val = $hdr->header($field) or return '';
+	ascii_html(join(', ', PublicInbox::Address::names($val)));
+}
 
-	my $refs = $hdr->header_raw('References');
-	if ($refs && $refs =~ /<([^>]+)>\s*\z/s) {
-		return $1;
-	}
-	undef;
+sub nr_to_s ($$$) {
+	my ($nr, $singular, $plural) = @_;
+	return "0 $plural" if $nr == 0;
+	$nr == 1 ? "$nr $singular" : "$nr $plural";
 }
 
 # this is already inside a <pre>
 sub index_entry {
-	my ($mime, $level, $state) = @_;
-	my $midx = $state->{anchor_idx}++;
-	my $ctx = $state->{ctx};
+	my ($smsg, $ctx, $more) = @_;
 	my $srch = $ctx->{srch};
-	my $part_nr = 0;
+	my $subj = $smsg->subject;
+	my $mid_raw = $smsg->mid;
+	my $id = id_compress($mid_raw, 1);
+	my $id_m = 'm'.$id;
+
+	my $root_anchor = $ctx->{root_anchor} || '';
+	my $irt;
+	my $obfs_ibx = $ctx->{-obfs_ibx};
+
+	my $rv = "<a\nhref=#e$id\nid=m$id>*</a> ";
+	$subj = '<b>'.ascii_html($subj).'</b>';
+	obfuscate_addrs($obfs_ibx, $subj) if $obfs_ibx;
+	$subj = "<u\nid=u>$subj</u>" if $root_anchor eq $id_m;
+	$rv .= $subj . "\n";
+	$rv .= _th_index_lite($mid_raw, \$irt, $id, $ctx);
+	my @tocc;
+	my $mime = $smsg->{mime};
 	my $hdr = $mime->header_obj;
-	my $enc = enc_for($hdr->header("Content-Type"));
-	my $subj = $hdr->header('Subject');
-
-	my $mid_raw = mid_clean(mid_mime($mime));
-	my $id = anchor_for($mid_raw);
-	my $seen = $state->{seen};
-	$seen->{$id} = "#$id"; # save the anchor for children, later
-
-	my $mid = PublicInbox::Hval->new_msgid($mid_raw);
-	my $from = $hdr->header('From');
-	my @from = Email::Address->parse($from);
-	$from = $from[0]->name;
-
-	my $root_anchor = $state->{root_anchor} || '';
-	my $path = $root_anchor ? '../../' : '';
-	my $href = $mid->as_href;
-	my $irt = in_reply_to($hdr);
-	my $parent_anchor = $seen->{anchor_for($irt)} if defined $irt;
-
-	$from = ascii_html($from);
-	$subj = ascii_html($subj);
-	$subj = "<a\nhref=\"${path}$href/\">$subj</a>";
-	$subj = "<u\nid=u>$subj</u>" if $root_anchor eq $id;
-
-	my $ts = _msg_date($hdr);
-	my $rv = "<pre\nid=s$midx>";
-	$rv .= "<b\nid=$id>$subj</b>\n";
-	my $txt = "${path}$href/raw";
-	my $fh = $state->{fh};
-	$fh->write($rv .= "- $from @ $ts UTC (<a\nhref=\"$txt\">raw</a>)\n\n");
-
-	my $fhref;
-	my $mhref = "${path}$href/";
-
-	# show full message if it's our root message
-	my $neq = $root_anchor ne $id;
-	if ($neq || ($neq && $level != 0 && !$ctx->{flat})) {
-		$fhref = "${path}$href/f/";
-	}
-	# scan through all parts, looking for displayable text
-	$mime->walk_parts(sub {
-		index_walk($fh, $_[0], $enc, \$part_nr, $fhref);
-	});
-	$mime->body_set('');
-	$rv = "\n" . html_footer($hdr, 0, undef, $ctx, $mhref);
-
-	if (defined $irt) {
-		unless (defined $parent_anchor) {
-			my $v = PublicInbox::Hval->new_msgid($irt, 1);
-			$v = $v->as_href;
-			$parent_anchor = "${path}$v/";
+	foreach my $f (qw(To Cc)) {
+		my $dst = _hdr_names_html($hdr, $f);
+		if ($dst ne '') {
+			obfuscate_addrs($obfs_ibx, $dst) if $obfs_ibx;
+			push @tocc, "$f: $dst";
 		}
-		$rv .= " <a\nhref=\"$parent_anchor\">parent</a>";
 	}
-	if (my $pct = $state->{pct}) { # used by SearchView.pm
-		$rv .= " [relevance $pct->{$mid_raw}%]";
-	} elsif ($srch) {
-		my $threaded = 'threaded';
+	my $from = _hdr_names_html($hdr, 'From');
+	obfuscate_addrs($obfs_ibx, $from) if $obfs_ibx;
+	$rv .= "From: $from @ ".fmt_ts($smsg->ds)." UTC";
+	my $upfx = $ctx->{-upfx};
+	my $mhref = $upfx . mid_escape($mid_raw) . '/';
+	$rv .= qq{ (<a\nhref="$mhref">permalink</a> / };
+	$rv .= qq{<a\nhref="${mhref}raw">raw</a>)\n};
+	$rv .= '  '.join('; +', @tocc) . "\n" if @tocc;
+
+	my $mapping = $ctx->{mapping};
+	if (!$mapping && (defined($irt) || defined($irt = in_reply_to($hdr)))) {
+		my $mirt = PublicInbox::Hval->new_msgid($irt);
+		my $href = $upfx . $mirt->{href}. '/';
+		my $html = $mirt->as_html;
+		$rv .= qq(In-Reply-To: &lt;<a\nhref="$href">$html</a>&gt;\n)
+	}
+	$rv .= "\n";
+
+	# scan through all parts, looking for displayable text
+	msg_iter($mime, sub { $rv .= add_text_body($mhref, $obfs_ibx, $_[0]) });
+
+	# add the footer
+	$rv .= "\n<a\nhref=#$id_m\nid=e$id>^</a> ".
+		"<a\nhref=\"$mhref\">permalink</a>" .
+		" <a\nhref=\"${mhref}raw\">raw</a>" .
+		" <a\nhref=\"${mhref}#R\">reply</a>";
+
+	my $hr;
+	if (my $pct = $ctx->{pct}) { # used by SearchView.pm
+		$rv .= "\t[relevance $pct->{$mid_raw}%]";
+		$hr = 1;
+	} elsif ($mapping) {
+		my $nested = 'nested';
 		my $flat = 'flat';
+		my $end = '';
 		if ($ctx->{flat}) {
+			$hr = 1;
 			$flat = "<b>$flat</b>";
 		} else {
-			$threaded = "<b>$threaded</b>";
+			$nested = "<b>$nested</b>";
 		}
-		$rv .= " [<a\nhref=\"${path}$href/t/#u\">$threaded</a>";
-		$rv .= "|<a\nhref=\"${path}$href/T/#u\">$flat</a>]";
+		$rv .= "\t[<a\nhref=\"${mhref}T/#u\">$flat</a>";
+		$rv .= "|<a\nhref=\"${mhref}t/#u\">$nested</a>]";
+		$rv .= " <a\nhref=#r$id>$ctx->{s_nr}</a>";
+	} else {
+		$hr = $ctx->{-hr};
 	}
-	$fh->write($rv .= '</pre>');
-}
 
-sub thread_html {
-	my ($ctx, $foot, $srch) = @_;
-	# $_[0] in sub is the Plack callback
-	sub { emit_thread_html($_[0], $ctx, $foot, $srch) }
+	$rv .= $more ? '</pre><hr><pre>' : '</pre>' if $hr;
+	$rv;
 }
 
-# only private functions below.
-
-sub emit_thread_html {
-	my ($res, $ctx, $foot, $srch) = @_;
-	my $mid = $ctx->{mid};
-	my $msgs = load_results($srch->get_thread($mid));
-	my $nr = scalar @$msgs;
-	return missing_thread($res, $ctx) if $nr == 0;
-	my $flat = $ctx->{flat};
-	my $seen = {};
-	my $state = {
-		res => $res,
-		ctx => $ctx,
-		seen => $seen,
-		root_anchor => anchor_for($mid),
-		anchor_idx => 0,
-		cur_level => 0,
-	};
+sub pad_link ($$;$) {
+	my ($mid, $level, $s) = @_;
+	$s ||= '...';
+	my $id = id_compress($mid, 1);
+	(' 'x19).indent_for($level).th_pfx($level)."<a\nhref=#r$id>($s)</a>\n";
+}
 
-	require PublicInbox::Git;
-	$ctx->{git} ||= PublicInbox::Git->new($ctx->{git_dir});
-	if ($flat) {
-		pre_anchor_entry($seen, $_) for (@$msgs);
-		__thread_entry($state, $_, 0) for (@$msgs);
-	} else {
-		my $th = thread_results($msgs);
-		thread_entry($state, $_, 0) for $th->rootset;
-		if (my $max = $state->{cur_level}) {
-			$state->{fh}->write(
-				('</ul></li>' x ($max - 1)) . '</ul>');
+sub _th_index_lite {
+	my ($mid_raw, $irt, $id, $ctx) = @_;
+	my $rv = '';
+	my $mapping = $ctx->{mapping} or return $rv;
+	my $pad = '  ';
+	my $mid_map = $mapping->{$mid_raw};
+	defined $mid_map or
+		return 'public-inbox BUG: '.ascii_html($mid_raw).' not mapped';
+	my ($attr, $node, $idx, $level) = @$mid_map;
+	my $children = $node->{children};
+	my $nr_c = scalar @$children;
+	my $nr_s = 0;
+	my $siblings;
+	if (my $smsg = $node->{smsg}) {
+		($$irt) = (($smsg->{references} || '') =~ m/<([^>]+)>\z/);
+	}
+	my $irt_map = $mapping->{$$irt} if defined $$irt;
+	if (defined $irt_map) {
+		$siblings = $irt_map->[1]->{children};
+		$nr_s = scalar(@$siblings) - 1;
+		$rv .= $pad . $irt_map->[0];
+		if ($idx > 0) {
+			my $prev = $siblings->[$idx - 1];
+			my $pmid = $prev->{id};
+			if ($idx > 2) {
+				my $s = ($idx - 1). ' preceding siblings ...';
+				$rv .= pad_link($pmid, $level, $s);
+			} elsif ($idx == 2) {
+				my $ppmid = $siblings->[0]->{id};
+				$rv .= $pad . $mapping->{$ppmid}->[0];
+			}
+			$rv .= $pad . $mapping->{$pmid}->[0];
+		}
+	}
+	my $s_s = nr_to_s($nr_s, 'sibling', 'siblings');
+	my $s_c = nr_to_s($nr_c, 'reply', 'replies');
+	$attr =~ s!\n\z!</b>\n!s;
+	$attr =~ s!<a\nhref.*</a> !!s; # no point in duplicating subject
+	$attr =~ s!<a\nhref=[^>]+>([^<]+)</a>!$1!s; # no point linking to self
+	$rv .= "<b>@ $attr";
+	if ($nr_c) {
+		my $cmid = $children->[0]->{id};
+		$rv .= $pad . $mapping->{$cmid}->[0];
+		if ($nr_c > 2) {
+			my $s = ($nr_c - 1). ' more replies';
+			$rv .= pad_link($cmid, $level + 1, $s);
+		} elsif (my $cn = $children->[1]) {
+			$rv .= $pad . $mapping->{$cn->{id}}->[0];
 		}
 	}
-	Email::Address->purge_cache;
-
-	# there could be a race due to a message being deleted in git
-	# but still being in the Xapian index:
-	my $fh = delete $state->{fh} or return missing_thread($res, $ctx);
 
-	my $final_anchor = $state->{anchor_idx};
-	my $next = "<a\nid=s$final_anchor>";
-	$next .= $final_anchor == 1 ? 'only message in' : 'end of';
-	$next .= " thread</a>, back to <a\nhref=\"../../\">index</a>";
-	$next .= "\ndownload thread: ";
-	$next .= "<a\nhref=\"../t.mbox.gz\">mbox.gz</a>";
-	$next .= " / follow: <a\nhref=\"../t.atom\">Atom feed</a>";
-	$fh->write('<hr /><pre>' . $next . "\n\n".
-			$foot .  '</pre></body></html>');
-	$fh->close;
+	my $next = $siblings->[$idx+1] if $siblings && $idx >= 0;
+	if ($next) {
+		my $nmid = $next->{id};
+		$rv .= $pad . $mapping->{$nmid}->[0];
+		my $nnext = $nr_s - $idx;
+		if ($nnext > 2) {
+			my $s = ($nnext - 1).' subsequent siblings';
+			$rv .= pad_link($nmid, $level, $s);
+		} elsif (my $nn = $siblings->[$idx + 2]) {
+			$rv .= $pad . $mapping->{$nn->{id}}->[0];
+		}
+	}
+	$rv .= $pad ."<a\nhref=#r$id>$s_s, $s_c; $ctx->{s_nr}</a>\n";
 }
 
-sub index_walk {
-	my ($fh, $part, $enc, $part_nr, $fhref) = @_;
-	my $s = add_text_body($enc, $part, $part_nr, $fhref, 1);
-
-	return if $s eq '';
+sub walk_thread {
+	my ($rootset, $ctx, $cb) = @_;
+	my @q = map { (0, $_, -1) } @$rootset;
+	while (@q) {
+		my ($level, $node, $i) = splice(@q, 0, 3);
+		defined $node or next;
+		$cb->($ctx, $level, $node, $i);
+		++$level;
+		$i = 0;
+		unshift @q, map { ($level, $_, $i++) } @{$node->{children}};
+	}
+}
 
-	$s .= "\n"; # ensure there's a trailing newline
+sub pre_thread  {
+	my ($ctx, $level, $node, $idx) = @_;
+	$ctx->{mapping}->{$node->{id}} = [ '', $node, $idx, $level ];
+	skel_dump($ctx, $level, $node);
+}
 
-	$fh->write($s);
+sub thread_index_entry {
+	my ($ctx, $level, $smsg) = @_;
+	my ($beg, $end) = thread_adj_level($ctx, $level);
+	$beg . '<pre>' . index_entry($smsg, $ctx, 0) . '</pre>' . $end;
 }
 
-sub enc_for {
-	my ($ct, $default) = @_;
-	$default ||= $enc_utf8;
-	defined $ct or return $default;
-	my $ct_parsed = parse_content_type($ct);
-	if ($ct_parsed) {
-		if (my $charset = $ct_parsed->{attributes}->{charset}) {
-			my $enc = find_encoding($charset);
-			return $enc if $enc;
+sub stream_thread ($$) {
+	my ($rootset, $ctx) = @_;
+	my $inbox = $ctx->{-inbox};
+	my @q = map { (0, $_) } @$rootset;
+	my $level;
+	my $smsg;
+	while (@q) {
+		$level = shift @q;
+		my $node = shift @q or next;
+		my $cl = $level + 1;
+		unshift @q, map { ($cl, $_) } @{$node->{children}};
+		$smsg = $inbox->smsg_mime($node->{smsg}) and last;
+	}
+	return missing_thread($ctx) unless $smsg;
+
+	$ctx->{-obfs_ibx} = $inbox->{obfuscate} ? $inbox : undef;
+	$ctx->{-title_html} = ascii_html($smsg->subject);
+	$ctx->{-html_tip} = thread_index_entry($ctx, $level, $smsg);
+	$smsg = undef;
+	PublicInbox::WwwStream->response($ctx, 200, sub {
+		return unless $ctx;
+		while (@q) {
+			$level = shift @q;
+			my $node = shift @q or next;
+			my $cl = $level + 1;
+			unshift @q, map { ($cl, $_) } @{$node->{children}};
+			if ($smsg = $inbox->smsg_mime($node->{smsg})) {
+				return thread_index_entry($ctx, $level, $smsg);
+			} else {
+				return ghost_index_entry($ctx, $level, $node);
+			}
 		}
+		my $ret = join('', thread_adj_level($ctx, 0));
+		$ret .= ${$ctx->{dst}}; # skel
+		$ctx = undef;
+		$ret;
+	});
+}
+
+sub thread_html {
+	my ($ctx) = @_;
+	my $mid = $ctx->{mid};
+	my $srch = $ctx->{srch};
+	my $sres = $srch->get_thread($mid);
+	my $msgs = load_results($srch, $sres);
+	my $nr = $sres->{total};
+	return missing_thread($ctx) if $nr == 0;
+	my $skel = '<hr><pre>';
+	$skel .= $nr == 1 ? 'only message in thread' : 'end of thread';
+	$skel .= ", back to <a\nhref=\"../../\">index</a>\n\n";
+	$skel .= "<b\nid=t>Thread overview:</b> ";
+	$skel .= $nr == 1 ? '(only message)' : "$nr+ messages";
+	$skel .= " (download: <a\nhref=\"../t.mbox.gz\">mbox.gz</a>";
+	$skel .= " / follow: <a\nhref=\"../t.atom\">Atom feed</a>)\n";
+	$skel .= "-- links below jump to the message on this page --\n";
+	$ctx->{-upfx} = '../../';
+	$ctx->{cur_level} = 0;
+	$ctx->{dst} = \$skel;
+	$ctx->{prev_attr} = '';
+	$ctx->{prev_level} = 0;
+	$ctx->{root_anchor} = anchor_for($mid);
+	$ctx->{mapping} = {};
+	$ctx->{s_nr} = "$nr+ messages in thread";
+
+	my $rootset = thread_results($ctx, $msgs);
+
+	# reduce hash lookups in pre_thread->skel_dump
+	my $inbox = $ctx->{-inbox};
+	$ctx->{-obfs_ibx} = $inbox->{obfuscate} ? $inbox : undef;
+	walk_thread($rootset, $ctx, *pre_thread);
+
+	$skel .= '</pre>';
+	return stream_thread($rootset, $ctx) unless $ctx->{flat};
+
+	# flat display: lazy load the full message from smsg
+	my $smsg;
+	while (my $m = shift @$msgs) {
+		$smsg = $inbox->smsg_mime($m) and last;
 	}
-	$default;
+	return missing_thread($ctx) unless $smsg;
+	$ctx->{-title_html} = ascii_html($smsg->subject);
+	$ctx->{-html_tip} = '<pre>'.index_entry($smsg, $ctx, scalar @$msgs);
+	$smsg = undef;
+	PublicInbox::WwwStream->response($ctx, 200, sub {
+		return unless $msgs;
+		$smsg = undef;
+		while (my $m = shift @$msgs) {
+			$smsg = $inbox->smsg_mime($m) and last;
+		}
+		return index_entry($smsg, $ctx, scalar @$msgs) if $smsg;
+		$msgs = undef;
+		$skel;
+	});
 }
 
 sub multipart_text_as_html {
-	my ($mime, $full_pfx, $srch) = @_;
+	my ($mime, $upfx, $obfs_ibx) = @_;
 	my $rv = "";
-	my $part_nr = 0;
-	my $enc = enc_for($mime->header("Content-Type"));
 
 	# scan through all parts, looking for displayable text
-	$mime->walk_parts(sub {
-		my ($part) = @_;
-		$part = add_text_body($enc, $part, \$part_nr, $full_pfx, 1);
-		$rv .= $part;
-		$rv .= "\n" if $part ne '';
-	});
-	$mime->body_set('');
+	msg_iter($mime, sub { $rv .= add_text_body($upfx, $obfs_ibx, $_[0]) });
 	$rv;
 }
 
-sub add_filename_line {
-	my ($enc, $fn) = @_;
-	my $len = 72;
-	my $pad = "-";
-	$fn = $enc->decode($fn);
-	$len -= length($fn);
-	$pad x= ($len/2) if ($len > 0);
-	"$pad " . ascii_html($fn) . " $pad\n";
-}
-
 sub flush_quote {
-	my ($quot, $n, $part_nr, $full_pfx, $final, $do_anchor) = @_;
-
-	# n.b.: do not use <blockquote> since it screws up alignment
-	# w.r.t. unquoted text.  Repliers may rely on pre-formatted
-	# alignment to point out a certain word in quoted text.
-	if ($full_pfx) {
-		if (!$final && scalar(@$quot) <= MAX_INLINE_QUOTED) {
-			# show quote inline
-			my $l = PublicInbox::Linkify->new;
-			my $rv = join('', map { $l->linkify_1($_) } @$quot);
-			@$quot = ();
-			$rv = ascii_html($rv);
-			return $l->linkify_2($rv);
-		}
+	my ($s, $l, $quot) = @_;
 
-		# show a short snippet of quoted text and link to full version:
-		@$quot = map { s/^(?:>\s*)+//gm; $_ } @$quot;
-		my $cur = join(' ', @$quot);
-		@$quot = split(/\s+/, $cur);
-		$cur = '';
-		do {
-			my $tmp = shift(@$quot);
-			my $len = length($tmp) + length($cur);
-			if ($len > MAX_TRUNC_LEN) {
-				@$quot = ();
-			} else {
-				$cur .= $tmp . ' ';
-			}
-		} while (@$quot && length($cur) < MAX_TRUNC_LEN);
-		@$quot = ();
-		$cur =~ s/ \z/ .../s;
-		$cur = ascii_html($cur);
-		my $nr = ++$$n;
-		"&gt; [<a\nhref=\"$full_pfx#q${part_nr}_$nr\">$cur</a>]\n";
+	# show everything in the full version with anchor from
+	# short version (see above)
+	my $rv = $l->linkify_1(join('', @$quot));
+	@$quot = ();
+
+	# we use a <span> here to allow users to specify their own
+	# color for quoted text
+	$rv = $l->linkify_2(ascii_html($rv));
+	$$s .= qq(<span\nclass="q">) . $rv . '</span>'
+}
+
+sub attach_link ($$$$;$) {
+	my ($upfx, $ct, $p, $fn, $err) = @_;
+	my ($part, $depth, @idx) = @$p;
+	my $nl = $idx[-1] > 1 ? "\n" : '';
+	my $idx = join('.', @idx);
+	my $size = bytes::length($part->body);
+
+	# hide attributes normally, unless we want to aid users in
+	# spotting MUA problems:
+	$ct =~ s/;.*// unless $err;
+	$ct = ascii_html($ct);
+	my $desc = $part->header('Content-Description');
+	$desc = $fn unless defined $desc;
+	$desc = '' unless defined $desc;
+	my $sfn;
+	if (defined $fn && $fn =~ /\A[[:alnum:]][\w\.-]+[[:alnum:]]\z/) {
+		$sfn = $fn;
+	} elsif ($ct eq 'text/plain') {
+		$sfn = 'a.txt';
 	} else {
-		# show everything in the full version with anchor from
-		# short version (see above)
-		my $l = PublicInbox::Linkify->new;
-		my $rv .= join('', map { $l->linkify_1($_) } @$quot);
-		@$quot = ();
-		$rv = ascii_html($rv);
-		return $l->linkify_2($rv) unless $do_anchor;
-		my $nr = ++$$n;
-		"<a\nid=q${part_nr}_$nr></a>" . $l->linkify_2($rv);
+		$sfn = 'a.bin';
+	}
+	my $ret = qq($nl<a\nhref="$upfx$idx-$sfn">);
+	if ($err) {
+		$ret .=
+"[-- Warning: decoded text below may be mangled --]\n";
 	}
+	$ret .= "[-- Attachment #$idx: ";
+	my $ts = "Type: $ct, Size: $size bytes";
+	$desc = ascii_html($desc);
+	$ret .= ($desc eq '') ? "$ts --]" : "$desc --]\n[-- $ts --]";
+	$ret .= "</a>\n";
 }
 
 sub add_text_body {
-	my ($enc_msg, $part, $part_nr, $full_pfx, $do_anchor) = @_;
-	return '' if $part->subparts;
-
-	my $ct = $part->content_type;
-	# account for filter bugs...
-	if (defined $ct && $ct =~ m!\btext/x?html\b!i) {
-		$part->body_set('');
-		return '';
-	}
-	my $enc = enc_for($ct, $enc_msg);
-	my $n = 0;
-	my $nr = 0;
-	my $s = $part->body;
-	$part->body_set('');
-	$s = $enc->decode($s);
-	my @lines = split(/^/m, $s);
-	$s = '';
+	my ($upfx, $obfs_ibx, $p) = @_;
+	# $p - from msg_iter: [ Email::MIME, depth, @idx ]
+	my ($part, $depth) = @$p; # attachment @idx is unused
+	my $ct = $part->content_type || 'text/plain';
+	my $fn = $part->filename;
+
+	if ($ct =~ m!\btext/x?html\b!i) {
+		return attach_link($upfx, $ct, $p, $fn);
+	}
+
+	my $s = eval { $part->body_str };
 
-	if ($$part_nr > 0) {
-		my $fn = $part->filename;
-		defined($fn) or $fn = "part #" . ($$part_nr + 1);
-		$s .= add_filename_line($enc, $fn);
+	# badly-encoded message? tell the world about it!
+	my $err = $@;
+	if ($err) {
+		if ($ct =~ m!\btext/plain\b!i) {
+			# Try to assume UTF-8 because Alpine seems to
+			# do wacky things and set charset=X-UNKNOWN
+			$part->charset_set('UTF-8');
+			$s = eval { $part->body_str };
+
+			# If forcing charset=UTF-8 failed,
+			# attach_link will warn further down...
+			$s = $part->body if $@;
+		} else {
+			return attach_link($upfx, $ct, $p, $fn);
+		}
 	}
 
+	my @lines = split(/^/m, $s);
+	$s = '';
+	if (defined($fn) || $depth > 0 || $err) {
+		$s .= attach_link($upfx, $ct, $p, $fn, $err);
+		$s .= "\n";
+	}
 	my @quot;
-	while (defined(my $cur = shift @lines)) {
+	my $l = PublicInbox::Linkify->new;
+	foreach my $cur (@lines) {
 		if ($cur !~ /^>/) {
 			# show the previously buffered quote inline
-			if (scalar @quot) {
-				$s .= flush_quote(\@quot, \$n, $$part_nr,
-						  $full_pfx, 0, $do_anchor);
-			}
+			flush_quote(\$s, $l, \@quot) if @quot;
 
 			# regular line, OK
-			my $l = PublicInbox::Linkify->new;
-			$cur = $l->linkify_1($cur);
-			$cur = ascii_html($cur);
-			$s .= $l->linkify_2($cur);
+			$l->linkify_1($cur);
+			$s .= $l->linkify_2(ascii_html($cur));
 		} else {
 			push @quot, $cur;
 		}
 	}
-	if (scalar @quot) {
-		$s .= flush_quote(\@quot, \$n, $$part_nr, $full_pfx, 1,
-				  $do_anchor);
-	}
-	++$$part_nr;
 
-	$s =~ s/[ \t]+$//sgm; # kill per-line trailing whitespace
-	$s =~ s/\A\n+//s; # kill leading blank lines
-	$s =~ s/\s+\z//s; # kill all trailing spaces (final "\n" added if ne '')
-	$s;
+	if (@quot) { # ugh, top posted
+		flush_quote(\$s, $l, \@quot);
+		obfuscate_addrs($obfs_ibx, $s) if $obfs_ibx;
+		$s;
+	} else {
+		obfuscate_addrs($obfs_ibx, $s) if $obfs_ibx;
+		if ($s =~ /\n\z/s) { # common, last line ends with a newline
+			$s;
+		} else { # some editors don't do newlines...
+			$s .= "\n";
+		}
+	}
 }
 
-sub headers_to_html_header {
-	my ($hdr, $full_pfx, $ctx) = @_;
+sub _msg_html_prepare {
+	my ($hdr, $ctx, $more, $nr) = @_;
 	my $srch = $ctx->{srch} if $ctx;
-	my $rv = "";
+	my $atom = '';
+	my $obfs_ibx = $ctx->{-obfs_ibx};
+	my $rv = '';
+	my $mids = mids($hdr);
+	my $multiple = scalar(@$mids) > 1; # zero, one, infinity
+	if ($nr == 0) {
+		if ($more) {
+			$rv .=
+"<pre>WARNING: multiple messages refer to this Message-ID\n</pre>";
+		}
+		$rv .= "<pre\nid=b>"; # anchor for body start
+	} else {
+		$rv .= '<pre>';
+	}
+	if ($srch) {
+		$ctx->{-upfx} = '../';
+	}
 	my @title;
-	my $mid = $hdr->header_raw('Message-ID');
-	$mid = PublicInbox::Hval->new_msgid($mid);
 	foreach my $h (qw(From To Cc Subject Date)) {
 		my $v = $hdr->header($h);
 		defined($v) && ($v ne '') or next;
 		$v = PublicInbox::Hval->new($v);
 
 		if ($h eq 'From') {
-			my @from = Email::Address->parse($v->raw);
-			$title[1] = ascii_html($from[0]->name);
+			my @n = PublicInbox::Address::names($v->raw);
+			$title[1] = ascii_html(join(', ', @n));
+			obfuscate_addrs($obfs_ibx, $title[1]) if $obfs_ibx;
 		} elsif ($h eq 'Subject') {
 			$title[0] = $v->as_html;
 			if ($srch) {
-				$rv .= "$h: <b\nid=t>";
-				$rv .= $v->as_html . "</b>\n";
+				$rv .= qq($h: <a\nhref="#r"\nid=t>);
+				$rv .= $v->as_html . "</a>\n";
 				next;
 			}
 		}
-		$rv .= "$h: " . $v->as_html . "\n";
+		$v = $v->as_html;
+		obfuscate_addrs($obfs_ibx, $v) if $obfs_ibx;
+		$rv .= "$h: $v\n";
 
 	}
-	$rv .= 'Message-ID: &lt;' . $mid->as_html . '&gt; ';
-	my $upfx = $full_pfx ? '' : '../';
-	$rv .= "(<a\nhref=\"${upfx}raw\">raw</a>)\n";
-	my $atom;
-	if ($srch) {
-		thread_inline(\$rv, $ctx, $hdr, $upfx);
-
-		$atom = qq{<link\nrel=alternate\ntitle="Atom feed"\n} .
-			qq!href="${upfx}t.atom"\ntype="application/atom+xml"/>!;
-	} else {
-		$rv .= _parent_headers_nosrch($hdr);
-		$atom = '';
+	$title[0] ||= '(no subject)';
+	$ctx->{-title_html} = join(' - ', @title);
+	foreach (@$mids) {
+		my $mid = PublicInbox::Hval->new_msgid($_) ;
+		my $mhtml = $mid->as_html;
+		if ($multiple) {
+			my $href = $mid->{href};
+			$rv .= "Message-ID: ";
+			$rv .= "<a\nhref=\"../$href/\">";
+			$rv .= "&lt;$mhtml&gt;</a> ";
+			$rv .= "(<a\nhref=\"../$href/raw\">raw</a>)\n";
+		} else {
+			$rv .= "Message-ID: &lt;$mhtml&gt; ";
+			$rv .= "(<a\nhref=\"raw\">raw</a>)\n";
+		}
 	}
+	$rv .= _parent_headers($hdr, $srch);
 	$rv .= "\n";
-
-	("<html><head><title>".  join(' - ', @title) . "</title>$atom".
-	 PublicInbox::Hval::STYLE . "</head><body><pre>" . $rv);
 }
 
-sub thread_inline {
-	my ($dst, $ctx, $hdr, $upfx) = @_;
+sub thread_skel {
+	my ($dst, $ctx, $hdr, $tpfx) = @_;
 	my $srch = $ctx->{srch};
-	my $mid = mid_clean($hdr->header_raw('Message-ID'));
+	my $mid = mids($hdr)->[0];
 	my $sres = $srch->get_thread($mid);
 	my $nr = $sres->{total};
-	my $expand = "<a\nhref=\"${upfx}t/#u\">expand</a> " .
-			"/ <a\nhref=\"${upfx}t.mbox.gz\">mbox.gz</a>";
+	my $expand = qq(expand[<a\nhref="${tpfx}T/#u">flat</a>) .
+	                qq(|<a\nhref="${tpfx}t/#u">nested</a>]  ) .
+			qq(<a\nhref="${tpfx}t.mbox.gz">mbox.gz</a>  ) .
+			qq(<a\nhref="${tpfx}t.atom">Atom feed</a>);
 
-	$$dst .= 'Thread: ';
 	my $parent = in_reply_to($hdr);
+	$$dst .= "\n<b>Thread overview: </b>";
 	if ($nr <= 1) {
 		if (defined $parent) {
-			$$dst .= "($expand)\n ";
-			$$dst .= ghost_parent("$upfx../", $parent) . "\n";
+			$$dst .= "$expand\n ";
+			$$dst .= ghost_parent("$tpfx../", $parent) . "\n";
 		} else {
-			$$dst .= "[no followups, yet] ($expand)\n";
+			$$dst .= "[no followups] $expand\n";
 		}
 		$ctx->{next_msg} = undef;
 		$ctx->{parent_msg} = $parent;
 		return;
 	}
 
-	$$dst .= "~$nr messages ($expand";
-	if ($nr > MAX_INLINE_QUOTED) {
-		$$dst .= qq! / <a\nhref="#b">[scroll down]</a>!;
-	}
-	$$dst .= ")\n";
+	$$dst .= "$nr+ messages / $expand";
+	$$dst .= qq!  <a\nhref="#b">top</a>\n!;
+
+	my $subj = $hdr->header('Subject');
+	defined $subj or $subj = '';
+	$ctx->{prev_subj} = [ split(/ /, $srch->subject_normalized($subj)) ];
+	$ctx->{cur} = $mid;
+	$ctx->{prev_attr} = '';
+	$ctx->{prev_level} = 0;
+	$ctx->{dst} = $dst;
+	$sres = load_results($srch, $sres);
+
+	# reduce hash lookups in skel_dump
+	my $ibx = $ctx->{-inbox};
+	$ctx->{-obfs_ibx} = $ibx->{obfuscate} ? $ibx : undef;
+	walk_thread(thread_results($ctx, $sres), $ctx, *skel_dump);
 
-	my $subj = $srch->subject_path($hdr->header('Subject'));
-	my $state = {
-		seen => { $subj => 1 },
-		srch => $srch,
-		cur => $mid,
-		prev_attr => '',
-		prev_level => 0,
-	};
-	for (thread_results(load_results($sres))->rootset) {
-		inline_dump($dst, $state, $upfx, $_, 0);
-	}
-	$$dst .= "<a\nid=b></a>"; # anchor for body start
-	$ctx->{next_msg} = $state->{next_msg};
 	$ctx->{parent_msg} = $parent;
 }
 
-sub _parent_headers_nosrch {
-	my ($hdr) = @_;
+sub _parent_headers {
+	my ($hdr, $srch) = @_;
 	my $rv = '';
 
 	my $irt = in_reply_to($hdr);
 	if (defined $irt) {
-		my $v = PublicInbox::Hval->new_msgid($irt, 1);
+		my $v = PublicInbox::Hval->new_msgid($irt);
 		my $html = $v->as_html;
-		my $href = $v->as_href;
+		my $href = $v->{href};
 		$rv .= "In-Reply-To: &lt;";
 		$rv .= "<a\nhref=\"../$href/\">$html</a>&gt;\n";
 	}
 
+	# do not display References: if search is present,
+	# we show the thread skeleton at the bottom, instead.
+	return $rv if $srch;
+
 	my $refs = $hdr->header_raw('References');
 	if ($refs) {
 		# avoid redundant URLs wasting bandwidth
@@ -502,441 +721,412 @@ sub _parent_headers_nosrch {
 		}
 
 		if (@refs) {
-			$rv .= 'References: '. join(' ', @refs) . "\n";
+			$rv .= 'References: '. join("\n\t", @refs) . "\n";
 		}
 	}
 	$rv;
 }
 
-sub mailto_arg_link {
-	my ($hdr) = @_;
-	my %cc; # everyone else
-	my $to; # this is the From address
-
-	foreach my $h (qw(From To Cc)) {
-		my $v = $hdr->header($h);
-		defined($v) && ($v ne '') or next;
-		my @addrs = Email::Address->parse($v);
-		foreach my $recip (@addrs) {
-			my $address = $recip->address;
-			my $dst = lc($address);
-			$cc{$dst} ||= $address;
-			$to ||= $dst;
-		}
-	}
-	Email::Address->purge_cache;
-	my @arg;
-
-	my $subj = $hdr->header('Subject') || '';
-	$subj = "Re: $subj" unless $subj =~ /\bRe:/i;
-	my $mid = $hdr->header_raw('Message-ID');
-	push @arg, "--in-reply-to='" . ascii_html($mid) . "'";
-	my $irt = uri_escape_utf8($mid);
-	delete $cc{$to};
-	push @arg, '--to=' . ascii_html($to);
-	$to = uri_escape_utf8($to);
-	$subj = uri_escape_utf8($subj);
-	my $cc = join(',', sort values %cc);
-	push @arg, '--cc=' . ascii_html($cc);
-	$cc = uri_escape_utf8($cc);
-	my $href = "mailto:$to?In-Reply-To=$irt&Cc=${cc}&Subject=$subj";
-	$href =~ s/%20/+/g;
-
-	(\@arg, $href);
-}
-
 sub html_footer {
-	my ($mime, $standalone, $full_pfx, $ctx, $mhref) = @_;
+	my ($hdr, $standalone, $ctx, $rhref) = @_;
 
 	my $srch = $ctx->{srch} if $ctx;
-	my $upfx = $full_pfx ? '../' : '../../';
-	my $tpfx = $full_pfx ? '' : '../';
+	my $upfx = '../';
+	my $tpfx = '';
 	my $idx = $standalone ? " <a\nhref=\"$upfx\">index</a>" : '';
 	my $irt = '';
-
-	if ($srch && $standalone) {
-		$idx .= qq{ / follow: <a\nhref="${tpfx}t.atom">Atom feed</a>\n};
-	}
 	if ($idx && $srch) {
-		my $p = $ctx->{parent_msg};
-		my $next = $ctx->{next_msg};
-		if ($p) {
-			$p = PublicInbox::Hval->new_msgid($p);
-			$p = $p->as_href;
-			$irt = "<a\nhref=\"$upfx$p/\">parent</a> ";
-		} else {
-			$irt = ' ' x length('parent ');
+		$idx .= "\n";
+		thread_skel(\$idx, $ctx, $hdr, $tpfx);
+		my ($next, $prev);
+		my $parent = '       ';
+		$next = $prev = '    ';
+
+		if (my $n = $ctx->{next_msg}) {
+			$n = PublicInbox::Hval->new_msgid($n)->{href};
+			$next = "<a\nhref=\"$upfx$n/\"\nrel=next>next</a>";
 		}
-		if ($next) {
-			$irt .= "<a\nhref=\"$upfx$next/\">next</a> ";
-		} else {
-			$irt .= ' ' x length('next ');
+		my $u;
+		my $par = $ctx->{parent_msg};
+		if ($par) {
+			$u = PublicInbox::Hval->new_msgid($par)->{href};
+			$u = "$upfx$u/";
 		}
-		if ($p || $next) {
-			$irt .= "<a\nhref=\"${tpfx}t/#u\">thread</a> ";
-		} else {
-			$irt .= ' ' x length('thread ');
+		if (my $p = $ctx->{prev_msg}) {
+			$prev = PublicInbox::Hval->new_msgid($p)->{href};
+			if ($p && $par && $p eq $par) {
+				$prev = "<a\nhref=\"$upfx$prev/\"\n" .
+					'rel=prev>prev parent</a>';
+				$parent = '';
+			} else {
+				$prev = "<a\nhref=\"$upfx$prev/\"\n" .
+					'rel=prev>prev</a>';
+				$parent = " <a\nhref=\"$u\">parent</a>" if $u;
+			}
+		} elsif ($u) { # unlikely
+			$parent = " <a\nhref=\"$u\"\nrel=prev>parent</a>";
 		}
+		$irt = "$next $prev$parent ";
 	} else {
 		$irt = '';
 	}
-
-	$mhref = './' unless defined $mhref;
-	$irt . qq(<a\nhref="${mhref}R/">reply</a>) . $idx;
+	$rhref ||= '#R';
+	$irt .= qq(<a\nhref="$rhref">reply</a>);
+	$irt .= $idx;
 }
 
 sub linkify_ref_nosrch {
-	my $v = PublicInbox::Hval->new_msgid($_[0], 1);
+	my $v = PublicInbox::Hval->new_msgid($_[0]);
 	my $html = $v->as_html;
-	my $href = $v->as_href;
+	my $href = $v->{href};
 	"&lt;<a\nhref=\"../$href/\">$html</a>&gt;";
 }
 
 sub anchor_for {
 	my ($msgid) = @_;
-	my $id = $msgid;
-	if ($id !~ /\A[a-f0-9]{40}\z/) {
-		$id = id_compress(mid_clean($id), 1);
-	}
-	'm' . $id;
-}
-
-sub thread_html_head {
-	my ($hdr, $state) = @_;
-	my $res = delete $state->{res} or die "BUG: no Plack callback in {res}";
-	my $fh = $res->([200, ['Content-Type'=> 'text/html; charset=UTF-8']]);
-	$state->{fh} = $fh;
-
-	my $s = ascii_html($hdr->header('Subject'));
-	$fh->write("<html><head><title>$s</title>".
-		qq{<link\nrel=alternate\ntitle="Atom feed"\n} .
-		qq!href="../t.atom"\ntype="application/atom+xml"/>! .
-		PublicInbox::Hval::STYLE .
-		"</head><body>");
-}
-
-sub pre_anchor_entry {
-	my ($seen, $mime) = @_;
-	my $id = anchor_for(mid_mime($mime));
-	$seen->{$id} = "#$id"; # save the anchor for children, later
+	'm' . id_compress($msgid, 1);
 }
 
 sub ghost_parent {
 	my ($upfx, $mid) = @_;
-	# 'subject dummy' is used internally by Mail::Thread
-	return '[no common parent]' if ($mid eq 'subject dummy');
 
 	$mid = PublicInbox::Hval->new_msgid($mid);
-	my $href = $mid->as_href;
+	my $href = $mid->{href};
 	my $html = $mid->as_html;
 	qq{[parent not found: &lt;<a\nhref="$upfx$href/">$html</a>&gt;]};
 }
 
-sub thread_adj_level {
-	my ($state, $level) = @_;
-
-	my $max = $state->{cur_level};
-	if ($level <= 0) {
-		return '' if $max == 0; # flat output
-
-		# reset existing lists
-		my $x = $max > 1 ? ('</ul></li>' x ($max - 1)) : '';
-		$state->{fh}->write($x . '</ul>');
-		$state->{cur_level} = 0;
-		return '';
-	}
-	if ($level == $max) { # continue existing list
-		$state->{fh}->write('<li>');
-	} elsif ($level < $max) {
-		my $x = $max > 1 ? ('</ul></li>' x ($max - $level)) : '';
-		$state->{fh}->write($x .= '<li>');
-		$state->{cur_level} = $level;
-	} else { # ($level > $max) # start a new level
-		$state->{cur_level} = $level;
-		$state->{fh}->write(($max ? '<li>' : '') . '<ul><li>');
-	}
-	'</li>';
-}
-
-sub ghost_flush {
-	my ($state, $upfx, $mid, $level) = @_;
-	my $end = '<pre>'. ghost_parent($upfx, $mid) . '</pre>';
-	$state->{fh}->write($end .= thread_adj_level($state, $level));
-}
-
-sub __thread_entry {
-	my ($state, $mime, $level) = @_;
-
-	# lazy load the full message from mini_mime:
-	$mime = eval {
-		my $path = mid2path(mid_clean(mid_mime($mime)));
-		Email::MIME->new($state->{ctx}->{git}->cat_file('HEAD:'.$path));
-	} or return;
-
-	thread_html_head($mime, $state) if $state->{anchor_idx} == 0;
-	if (my $ghost = delete $state->{ghost}) {
-		# n.b. ghost messages may only be parents, not children
-		foreach my $g (@$ghost) {
-			ghost_flush($state, '../../', @$g);
-		}
-	}
-	my $end = thread_adj_level($state, $level);
-	index_entry($mime, $level, $state);
-	$state->{fh}->write($end) if $end;
-
-	1;
-}
-
 sub indent_for {
 	my ($level) = @_;
-	INDENT x ($level - 1);
-}
-
-sub __ghost_prepare {
-	my ($state, $node, $level) = @_;
-	my $ghost = $state->{ghost} ||= [];
-	push @$ghost, [ $node->messageid, $level ];
-}
-
-sub thread_entry {
-	my ($state, $node, $level) = @_;
-	return unless $node;
-	if (my $mime = $node->message) {
-		unless (__thread_entry($state, $mime, $level)) {
-			__ghost_prepare($state, $node, $level);
-		}
-	} else {
-		__ghost_prepare($state, $node, $level);
-	}
-
-	thread_entry($state, $node->child, $level + 1);
-	thread_entry($state, $node->next, $level);
+	$level ? INDENT x ($level - 1) : '';
 }
 
 sub load_results {
-	my ($sres) = @_;
-
-	[ map { $_->mini_mime } @{delete $sres->{msgs}} ];
-}
-
-sub msg_timestamp {
-	my ($hdr) = @_;
-	my $ts = eval { str2time($hdr->header('Date')) };
-	defined($ts) ? $ts : 0;
+	my ($srch, $sres) = @_;
+	my $msgs = delete $sres->{msgs};
+	$srch->retry_reopen(sub { [ map { $_->mid; $_ } @$msgs ] });
 }
 
 sub thread_results {
-	my ($msgs, $nosubject) = @_;
-	require PublicInbox::Thread;
-	my $th = PublicInbox::Thread->new(@$msgs);
-
-	# WARNING! both these Mail::Thread knobs were found by inspecting
-	# the Mail::Thread 2.55 source code, and we have some monkey patches
-	# in PublicInbox::Thread to fix memory leaks.  Since Mail::Thread
-	# appears unmaintained, I suppose it's safe to depend on these
-	# variables for now:
-	no warnings 'once';
-	$Mail::Thread::nosubject = $nosubject;
-	# Keep ghosts with only a single direct child:
-	$Mail::Thread::noprune = 1;
-	$th->thread;
-	$th->order(*sort_ts);
-	$th
+	my ($ctx, $msgs) = @_;
+	require PublicInbox::SearchThread;
+	PublicInbox::SearchThread::thread($msgs, *sort_ds, $ctx->{-inbox});
 }
 
 sub missing_thread {
-	my ($res, $ctx) = @_;
+	my ($ctx) = @_;
 	require PublicInbox::ExtMsg;
-
-	$res->(PublicInbox::ExtMsg::ext_msg($ctx))
+	PublicInbox::ExtMsg::ext_msg($ctx);
 }
 
 sub _msg_date {
 	my ($hdr) = @_;
-	my $ts = $hdr->header('X-PI-TS') || msg_timestamp($hdr);
-	fmt_ts($ts);
+	fmt_ts(msg_datestamp($hdr));
 }
 
 sub fmt_ts { POSIX::strftime('%Y-%m-%d %k:%M', gmtime($_[0])) }
 
-sub _inline_header {
-	my ($dst, $state, $upfx, $hdr, $level) = @_;
-	my $dot = $level == 0 ? '' : '` ';
+sub dedupe_subject {
+	my ($prev_subj, $subj, $val) = @_;
+
+	my $omit = ''; # '"' denotes identical text omitted
+	my (@prev_pop, @curr_pop);
+	while (@$prev_subj && @$subj && $subj->[-1] eq $prev_subj->[-1]) {
+		push(@prev_pop, pop(@$prev_subj));
+		push(@curr_pop, pop(@$subj));
+		$omit ||= $val;
+	}
+	pop @$subj if @$subj && $subj->[-1] =~ /^re:\s*/i;
+	if (scalar(@curr_pop) == 1) {
+		$omit = '';
+		push @$prev_subj, @prev_pop;
+		push @$subj, @curr_pop;
+	}
+	$omit;
+}
+
+sub skel_dump {
+	my ($ctx, $level, $node) = @_;
+	my $smsg = $node->{smsg} or return _skel_ghost($ctx, $level, $node);
+
+	my $dst = $ctx->{dst};
+	my $cur = $ctx->{cur};
+	my $mid = $smsg->{mid};
 
-	my $cur = $state->{cur};
-	my $mid = mid_clean($hdr->header_raw('Message-ID'));
-	my $f = ascii_html($hdr->header('X-PI-From'));
-	my $d = _msg_date($hdr);
-	my $pfx = ' ' . $d . ' ' . indent_for($level);
+	my $f = ascii_html($smsg->from_name);
+	my $obfs_ibx = $ctx->{-obfs_ibx};
+	obfuscate_addrs($obfs_ibx, $f) if $obfs_ibx;
+
+	my $d = fmt_ts($smsg->{ds}) . ' ' . indent_for($level) . th_pfx($level);
 	my $attr = $f;
-	$state->{first_level} ||= $level;
+	$ctx->{first_level} ||= $level;
 
-	if ($attr ne $state->{prev_attr} || $state->{prev_level} > $level) {
-		$state->{prev_attr} = $attr;
-	} else {
-		$attr = '';
+	if ($attr ne $ctx->{prev_attr} || $ctx->{prev_level} > $level) {
+		$ctx->{prev_attr} = $attr;
 	}
-	$state->{prev_level} = $level;
+	$ctx->{prev_level} = $level;
 
 	if ($cur) {
 		if ($cur eq $mid) {
-			delete $state->{cur};
-			$$dst .= "$pfx$dot<b><a\nid=r\nhref=\"#b\">".
+			delete $ctx->{cur};
+			$$dst .= "<b>$d<a\nid=r\nhref=\"#t\">".
 				 "$attr [this message]</a></b>\n";
-
 			return;
+		} else {
+			$ctx->{prev_msg} = $mid;
 		}
 	} else {
-		$state->{next_msg} ||= $mid;
+		$ctx->{next_msg} ||= $mid;
 	}
 
 	# Subject is never undef, this mail was loaded from
 	# our Xapian which would've resulted in '' if it were
 	# really missing (and Filter rejects empty subjects)
-	my $s = $hdr->header('Subject');
-	my $h = $state->{srch}->subject_path($s);
-	if ($state->{seen}->{$h}) {
-		$s = undef;
+	my @subj = split(/ /, $ctx->{srch}->subject_normalized($smsg->subject));
+
+	# remove common suffixes from the subject if it matches the previous,
+	# so we do not show redundant text at the end.
+	my $prev_subj = $ctx->{prev_subj} || [];
+	$ctx->{prev_subj} = [ @subj ];
+	my $omit = dedupe_subject($prev_subj, \@subj, '&#34; ');
+	my $end;
+	if (@subj) {
+		my $subj = join(' ', @subj);
+		$subj = ascii_html($subj);
+		obfuscate_addrs($obfs_ibx, $subj) if $obfs_ibx;
+		$end = "$subj</a> $omit$f\n"
 	} else {
-		$state->{seen}->{$h} = 1;
-		$s = PublicInbox::Hval->new($s);
-		$s = $s->as_html;
+		$end = "$f</a>\n";
 	}
-	my $m = PublicInbox::Hval->new_msgid($mid);
-	$m = $upfx . '../' . $m->as_href . '/';
-	if (defined $s) {
-		$$dst .= "$pfx$dot<a\nhref=\"$m\">$s</a> $attr\n";
+	my $m;
+	my $id = '';
+	my $mapping = $ctx->{mapping};
+	if ($mapping) {
+		my $map = $mapping->{$mid};
+		$id = id_compress($mid, 1);
+		$m = '#m'.$id;
+		$map->[0] = "$d<a\nhref=\"$m\">$end";
+		$id = "\nid=r".$id;
 	} else {
-		$$dst .= "$pfx$dot<a\nhref=\"$m\">$f</a>\n";
+		$m = $ctx->{-upfx}.mid_escape($mid).'/';
 	}
+	$$dst .=  $d . "<a\nhref=\"$m\"$id>" . $end;
 }
 
-sub inline_dump {
-	my ($dst, $state, $upfx, $node, $level) = @_;
-	return unless $node;
-	if (my $mime = $node->message) {
-		my $hdr = $mime->header_obj;
-		my $mid = mid_clean($hdr->header_raw('Message-ID'));
-		_inline_header($dst, $state, $upfx, $hdr, $level);
+sub _skel_ghost {
+	my ($ctx, $level, $node) = @_;
+
+	my $mid = $node->{id};
+	my $d = $ctx->{pct} ? '    [irrelevant] ' # search result
+			    : '     [not found] ';
+	$d .= indent_for($level) . th_pfx($level);
+	my $upfx = $ctx->{-upfx};
+	my $m = PublicInbox::Hval->new_msgid($mid);
+	my $href = $upfx . $m->{href} . '/';
+	my $html = $m->as_html;
+
+	my $mapping = $ctx->{mapping};
+	my $map = $mapping->{$mid} if $mapping;
+	if ($map) {
+		my $id = id_compress($mid, 1);
+		$map->[0] = $d . qq{&lt;<a\nhref=#r$id>$html</a>&gt;\n};
+		$d .= qq{&lt;<a\nhref="$href"\nid=r$id>$html</a>&gt;\n};
 	} else {
-		my $dot = $level == 0 ? '' : '` ';
-		my $pfx = (' ' x length(' 1970-01-01 13:37 ')).
-			indent_for($level) . $dot;
-		$$dst .= $pfx;
-		$$dst .= ghost_parent("$upfx../", $node->messageid) . "\n";
+		$d .= qq{&lt;<a\nhref="$href">$html</a>&gt;\n};
 	}
-	inline_dump($dst, $state, $upfx, $node->child, $level+1);
-	inline_dump($dst, $state, $upfx, $node->next, $level);
+	my $dst = $ctx->{dst};
+	$$dst .= $d;
 }
 
-sub sort_ts {
-	sort {
-		(eval { $a->topmost->message->header('X-PI-TS') } || 0) <=>
-		(eval { $b->topmost->message->header('X-PI-TS') } || 0)
-	} @_;
+sub sort_ds {
+	[ sort {
+		(eval { $a->topmost->{smsg}->ds } || 0) <=>
+		(eval { $b->topmost->{smsg}->ds } || 0)
+	} @{$_[0]} ];
 }
 
-sub rsort_ts {
-	sort {
-		(eval { $b->topmost->message->header('X-PI-TS') } || 0) <=>
-		(eval { $a->topmost->message->header('X-PI-TS') } || 0)
-	} @_;
+# accumulate recent topics if search is supported
+# returns 200 if done, 404 if not
+sub acc_topic {
+	my ($ctx, $level, $node) = @_;
+	my $srch = $ctx->{srch};
+	my $mid = $node->{id};
+	my $x = $node->{smsg} || $ctx->{-inbox}->smsg_by_mid($mid);
+	my ($subj, $ds);
+	my $topic;
+	if ($x) {
+		$subj = $x->subject;
+		$subj = $srch->subject_normalized($subj);
+		$ds = $x->ds;
+		if ($level == 0) {
+			$topic = [ $ds, 1, { $subj => $mid }, $subj ];
+			$ctx->{-cur_topic} = $topic;
+			push @{$ctx->{order}}, $topic;
+			return;
+		}
+
+		$topic = $ctx->{-cur_topic}; # should never be undef
+		$topic->[0] = $ds if $ds > $topic->[0];
+		$topic->[1]++;
+		my $seen = $topic->[2];
+		if (scalar(@$topic) == 3) { # parent was a ghost
+			push @$topic, $subj;
+		} elsif (!$seen->{$subj}) {
+			push @$topic, $level, $subj;
+		}
+		$seen->{$subj} = $mid; # latest for subject
+	} else { # ghost message
+		return if $level != 0; # ignore child ghosts
+		$topic = [ -666, 0, {} ];
+		$ctx->{-cur_topic} = $topic;
+		push @{$ctx->{order}}, $topic;
+	}
 }
 
-# accumulate recent topics if search is supported
-# returns 1 if done, undef if not
-sub add_topic {
-	my ($state, $node, $level) = @_;
-	return unless $node;
-	my $child_adjust = 1;
+sub dump_topics {
+	my ($ctx) = @_;
+	my $order = delete $ctx->{order}; # [ ds, subj1, subj2, subj3, ... ]
+	if (!@$order) {
+		$ctx->{-html_tip} = '<pre>[No topics in range]</pre>';
+		return 404;
+	}
 
-	if (my $x = $node->message) {
-		$x = $x->header_obj;
-		my $subj;
+	my @out;
+	my $ibx = $ctx->{-inbox};
+	my $obfs_ibx = $ibx->{obfuscate} ? $ibx : undef;
+	my $srch = $ctx->{srch};
 
-		$subj = $x->header('Subject');
-		$subj = $state->{srch}->subject_normalized($subj);
+	# sort by recency, this allows new posts to "bump" old topics...
+	foreach my $topic (sort { $b->[0] <=> $a->[0] } @$order) {
+		my ($ds, $n, $seen, $top, @ex) = @$topic;
+		@$topic = ();
+		next unless defined $top;  # ghost topic
+		my $mid = delete $seen->{$top};
+		my $href = mid_escape($mid);
+		my $prev_subj = [ split(/ /, $top) ];
+		$top = PublicInbox::Hval->new($top)->as_html;
+		$ds = fmt_ts($ds);
 
-		if (++$state->{subjs}->{$subj} == 1) {
-			push @{$state->{order}}, [ $level, $subj ];
+		# $n isn't the total number of posts on the topic,
+		# just the number of posts in the current results window
+		my $anchor;
+		if ($n == 1) {
+			$n = '';
+			$anchor = '#u'; # top of only message
+		} else {
+			$n = " ($n+ messages)";
+			$anchor = '#t'; # thread skeleton
 		}
 
-		my $mid = mid_clean($x->header_raw('Message-ID'));
-
-		my $ts = $x->header('X-PI-TS');
-		my $exist = $state->{latest}->{$subj};
-		if (!$exist || $exist->[1] < $ts) {
-			$state->{latest}->{$subj} = [ $mid, $ts ];
+		my $mbox = qq(<a\nhref="$href/t.mbox.gz">mbox.gz</a>);
+		my $atom = qq(<a\nhref="$href/t.atom">Atom</a>);
+		my $s = "<a\nhref=\"$href/T/$anchor\"><b>$top</b></a>\n" .
+			" $ds UTC $n - $mbox / $atom\n";
+		for (my $i = 0; $i < scalar(@ex); $i += 2) {
+			my $level = $ex[$i];
+			my $subj = $ex[$i + 1];
+			$mid = delete $seen->{$subj};
+			my @subj = split(/ /, $srch->subject_normalized($subj));
+			my @next_prev = @subj; # full copy
+			my $omit = dedupe_subject($prev_subj, \@subj, ' &#34;');
+			$prev_subj = \@next_prev;
+			$subj = ascii_html(join(' ', @subj));
+			obfuscate_addrs($obfs_ibx, $subj) if $obfs_ibx;
+			$href = mid_escape($mid);
+			$s .= indent_for($level) . TCHILD;
+			$s .= "<a\nhref=\"$href/T/#u\">$subj</a>$omit\n";
 		}
-	} else {
-		# ghost message, do not bump level
-		$child_adjust = 0;
+		push @out, $s;
 	}
-
-	add_topic($state, $node->child, $level + $child_adjust);
-	add_topic($state, $node->next, $level);
+	$ctx->{-html_tip} = '<pre>' . join("\n", @out) . '</pre>';
+	200;
 }
 
-sub dump_topics {
-	my ($state) = @_;
-	my $order = $state->{order};
-	my $subjs = $state->{subjs};
-	my $latest = $state->{latest};
-	return "\n[No topics in range]</pre>" unless (scalar @$order);
-	my $dst = '';
-	my $pfx;
-	my $prev = 0;
-	my $prev_attr = '';
-	while (defined(my $info = shift @$order)) {
-		my ($level, $subj) = @$info;
-		my $n = delete $subjs->{$subj};
-		my ($mid, $ts) = @{delete $latest->{$subj}};
-		$mid = PublicInbox::Hval->new_msgid($mid)->as_href;
-		$subj = PublicInbox::Hval->new($subj)->as_html;
-		$pfx = indent_for($level);
-		my $nl = $level == $prev ? "\n" : '';
-		my $dot = $level == 0 ? '' : '` ';
-		$dst .= "$nl$pfx$dot<a\nhref=\"$mid/t/#u\"><b>$subj</b></a>\n";
-
-		$ts = fmt_ts($ts);
-		my $attr = " $ts UTC";
+sub index_nav { # callback for WwwStream
+	my (undef, $ctx) = @_;
+	delete $ctx->{qp} or return;
+	my ($next, $prev);
+	$next = $prev = '    ';
+	my $latest = '';
 
-		# $n isn't the total number of posts on the topic,
-		# just the number of posts in the current results window
-		$n = $n == 1 ? '' : " ($n+ messages)";
-
-		if ($level == 0 || $attr ne $prev_attr) {
-			my $mbox = qq(<a\nhref="$mid/t.mbox.gz">mbox.gz</a>);
-			my $atom = qq(<a\nhref="$mid/t.atom">Atom</a>);
-			$pfx .= INDENT if $level > 0;
-			$dst .= $pfx . $attr . $n . " - $mbox / $atom\n";
-			$prev_attr = $attr;
+	my $next_o = $ctx->{-next_o};
+	if ($next_o) {
+		$next = qq!<a\nhref="?o=$next_o"\nrel=next>next</a>!;
+	}
+	if (my $cur_o = $ctx->{-cur_o}) {
+		$latest = qq! <a\nhref=.>latest</a>!;
+
+		my $o = $cur_o - ($next_o - $cur_o);
+		if ($o > 0) {
+			$prev = qq!<a\nhref="?o=$o"\nrel=prev>prev</a>!;
+		} elsif ($o == 0) {
+			$prev = qq!<a\nhref=.\nrel=prev>prev</a>!;
 		}
 	}
-	$dst .= '</pre>';
+	"<hr><pre>page: $next $prev$latest</pre>";
 }
 
-sub emit_index_topics {
-	my ($state) = @_;
-	my $off = $state->{ctx}->{cgi}->param('o');
-	$off = 0 unless defined $off;
-	$state->{order} = [];
-	$state->{subjs} = {};
-	$state->{latest} = {};
-	my $max = 25;
-	my %opts = ( offset => int $off, limit => $max * 4 );
-	while (scalar @{$state->{order}} < $max) {
-		my $sres = $state->{srch}->query('', \%opts);
-		my $nr = scalar @{$sres->{msgs}} or last;
+sub index_topics {
+	my ($ctx) = @_;
+	my ($off) = (($ctx->{qp}->{o} || '0') =~ /(\d+)/);
+	my $lim = 200;
+	my $opts = { offset => $off, limit => $lim };
 
-		for (rsort_ts(thread_results(load_results($sres), 1)->rootset)){
-			add_topic($state, $_, 0);
+	$ctx->{order} = [];
+	my $srch = $ctx->{srch};
+
+	my $qs = '';
+	# this complicated bit cuts loading time by over 400ms on my system:
+	if ($off == 0) {
+		my ($min, $max) = $ctx->{-inbox}->mm->minmax;
+		my $n = $max - $lim;
+		$n = $min if $n < $min;
+		for (; $qs eq '' && $n >= $min; --$n) {
+			my $smsg = $srch->lookup_article($n) or next;
+			$qs = POSIX::strftime('d:%Y%m%d..', gmtime($smsg->ts));
 		}
-		$opts{offset} += $nr;
 	}
 
-	$state->{fh}->write(dump_topics($state));
-	$opts{offset};
+	my $sres = $srch->query($qs, $opts);
+	my $nr = scalar @{$sres->{msgs}};
+	if ($nr) {
+		$sres = load_results($srch, $sres);
+		walk_thread(thread_results($ctx, $sres), $ctx, *acc_topic);
+	}
+	$ctx->{-next_o} = $off + $nr;
+	$ctx->{-cur_o} = $off;
+	PublicInbox::WwwStream->response($ctx, dump_topics($ctx), *index_nav);
+}
+
+sub thread_adj_level {
+	my ($ctx, $level) = @_;
+
+	my $max = $ctx->{cur_level};
+	if ($level <= 0) {
+		return ('', '') if $max == 0; # flat output
+
+		# reset existing lists
+		my $beg = $max > 1 ? ('</ul></li>' x ($max - 1)) : '';
+		$ctx->{cur_level} = 0;
+		("$beg</ul>", '');
+	} elsif ($level == $max) { # continue existing list
+		qw(<li> </li>);
+	} elsif ($level < $max) {
+		my $beg = $max > 1 ? ('</ul></li>' x ($max - $level)) : '';
+		$ctx->{cur_level} = $level;
+		("$beg<li>", '</li>');
+	} else { # ($level > $max) # start a new level
+		$ctx->{cur_level} = $level;
+		my $beg = ($max ? '<li>' : '') . '<ul><li>';
+		($beg, '</li>');
+	}
+}
+
+sub ghost_index_entry {
+	my ($ctx, $level, $node) = @_;
+	my ($beg, $end) = thread_adj_level($ctx,  $level);
+	$beg . '<pre>'. ghost_parent($ctx->{-upfx}, $node->{id})
+		. '</pre>' . $end;
 }
 
 1;