X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FView.pm;h=ca02ae057f2343ad4d66f9202a8563ccfc46c6ac;hb=7ee3643af9b72cad2abf9cde4a48e389550ad71b;hp=4cb72bea849e6b28b4bfacc2684af1daf2689128;hpb=77eafbd653d2efac546f2c330d8cf5e84bef2712;p=public-inbox.git

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 4cb72bea..ca02ae05 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -1,14 +1,15 @@
-# Copyright (C) 2014-2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 2014-2021 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 bytes (); # only for bytes::length
+use v5.10.1;
+use List::Util qw(max);
 use PublicInbox::MsgTime qw(msg_datestamp);
-use PublicInbox::Hval qw(ascii_html obfuscate_addrs prurl mid_href);
+use PublicInbox::Hval qw(ascii_html obfuscate_addrs prurl mid_href
+			ts2str fmt_ts);
 use PublicInbox::Linkify;
 use PublicInbox::MID qw(id_compress mids mids_for_index references
 			$MID_EXTRACT);
@@ -18,9 +19,9 @@ use PublicInbox::WwwStream qw(html_oneshot);
 use PublicInbox::Reply;
 use PublicInbox::ViewDiff qw(flush_diff);
 use PublicInbox::Eml;
-use POSIX qw(strftime);
 use Time::Local qw(timegm);
 use PublicInbox::Smsg qw(subject_normalized);
+use PublicInbox::ContentHash qw(content_hash);
 use constant COLS => 72;
 use constant INDENT => '  ';
 use constant TCHILD => '` ';
@@ -30,13 +31,17 @@ sub msg_page_i {
 	my ($ctx, $eml) = @_;
 	if ($eml) { # called by WwwStream::async_eml or getline
 		my $smsg = $ctx->{smsg};
-		$ctx->{smsg} = $ctx->{over}->next_by_mid(@{$ctx->{next_arg}});
+		my $over = $ctx->{ibx}->over;
+		$ctx->{smsg} = $over ? $over->next_by_mid(@{$ctx->{next_arg}})
+				: $ctx->gone('over');
 		$ctx->{mhref} = ($ctx->{nr} || $ctx->{smsg}) ?
 				"../${\mid_href($smsg->{mid})}/" : '';
 		my $obuf = $ctx->{obuf} = _msg_page_prepare_obuf($eml, $ctx);
-		multipart_text_as_html($eml, $ctx);
+		if (length($$obuf)) {
+			multipart_text_as_html($eml, $ctx);
+			$$obuf .= '</pre><hr>';
+		}
 		delete $ctx->{obuf};
-		$$obuf .= '</pre><hr>';
 		$$obuf .= html_footer($ctx, $ctx->{first_hdr}) if !$ctx->{smsg};
 		$$obuf;
 	} else { # called by WwwStream::async_next or getline
@@ -47,14 +52,16 @@ sub msg_page_i {
 # /$INBOX/$MSGID/ for unindexed v1 inboxes
 sub no_over_html ($) {
 	my ($ctx) = @_;
-	my $bref = $ctx->{-inbox}->msg_by_mid($ctx->{mid}) or return; # 404
+	my $bref = $ctx->{ibx}->msg_by_mid($ctx->{mid}) or return; # 404
 	my $eml = PublicInbox::Eml->new($bref);
 	$ctx->{mhref} = '';
 	PublicInbox::WwwStream::init($ctx);
 	my $obuf = $ctx->{obuf} = _msg_page_prepare_obuf($eml, $ctx);
-	multipart_text_as_html($eml, $ctx);
+	if (length($$obuf)) {
+		multipart_text_as_html($eml, $ctx);
+		$$obuf .= '</pre><hr>';
+	}
 	delete $ctx->{obuf};
-	$$obuf .= '</pre><hr>';
 	eval { $$obuf .= html_footer($ctx, $eml) };
 	html_oneshot($ctx, 200, $obuf);
 }
@@ -63,12 +70,18 @@ sub no_over_html ($) {
 
 sub msg_page {
 	my ($ctx) = @_;
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	$ctx->{-obfs_ibx} = $ibx->{obfuscate} ? $ibx : undef;
-	my $over = $ctx->{over} = $ibx->over or return no_over_html($ctx);
+	my $over = $ibx->over or return no_over_html($ctx);
 	my ($id, $prev);
 	my $next_arg = $ctx->{next_arg} = [ $ctx->{mid}, \$id, \$prev ];
-	$ctx->{smsg} = $over->next_by_mid(@$next_arg) or return; # undef == 404
+
+	my $smsg = $ctx->{smsg} = $over->next_by_mid(@$next_arg) or
+		return; # undef == 404
+
+	# allow user to easily browse the range around this message if
+	# they have ->over
+	$ctx->{-t_max} = $smsg->{ts};
 	PublicInbox::WwwStream::aresponse($ctx, 200, \&msg_page_i);
 }
 
@@ -81,7 +94,7 @@ sub msg_reply ($$) {
 	 'https://en.wikipedia.org/wiki/Posting_style#Interleaved_style';
 
 	my $info = '';
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	if (my $url = $ibx->{infourl}) {
 		$url = prurl($ctx->{env}, $url);
 		$info = qq(\n  List information: <a\nhref="$url">$url</a>\n);
@@ -168,9 +181,6 @@ sub nr_to_s ($$$) {
 	$nr == 1 ? "$nr $singular" : "$nr $plural";
 }
 
-# human-friendly format
-sub fmt_ts ($) { strftime('%Y-%m-%d %k:%M', gmtime($_[0])) }
-
 # Displays the text of of the message for /$INBOX/$MSGID/[Tt]/ endpoint
 # this is already inside a <pre>
 sub eml_entry {
@@ -272,8 +282,15 @@ sub eml_entry {
 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";
+	my $href = defined($mid) ?
+		("<a\nhref=#r".id_compress($mid, 1).">($s)</a>\n") :
+		"($s)\n";
+	(' 'x19).indent_for($level).th_pfx($level).$href;
+}
+
+sub _skel_hdr {
+	# my ($mapping, $mid) = @_;
+	($_[0]->{$_[1] // \'bogus'} // [ "(?)\n" ])->[0];
 }
 
 sub _th_index_lite {
@@ -305,10 +322,11 @@ sub _th_index_lite {
 				my $s = ($idx - 1). ' preceding siblings ...';
 				$rv .= pad_link($pmid, $level, $s);
 			} elsif ($idx == 2) {
-				my $ppmid = $siblings->[0]->{mid};
-				$rv .= $pad . $mapping->{$ppmid}->[0];
+				$rv .= $pad . _skel_hdr($mapping,
+						$siblings->[0] ?
+						$siblings->[0]->{mid} : undef);
 			}
-			$rv .= $pad . $mapping->{$pmid}->[0];
+			$rv .= $pad . _skel_hdr($mapping, $pmid);
 		}
 	}
 	my $s_s = nr_to_s($nr_s, 'sibling', 'siblings');
@@ -318,26 +336,26 @@ sub _th_index_lite {
 	$attr =~ s!<a\nhref=[^>]+>([^<]+)</a>!$1!s; # no point linking to self
 	$rv .= "<b>@ $attr";
 	if ($nr_c) {
-		my $cmid = $children->[0]->{mid};
-		$rv .= $pad . $mapping->{$cmid}->[0];
+		my $cmid = $children->[0] ? $children->[0]->{mid} : undef;
+		$rv .= $pad . _skel_hdr($mapping, $cmid);
 		if ($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->{mid}}->[0];
+			$rv .= $pad . _skel_hdr($mapping, $cn->{mid});
 		}
 	}
 
 	my $next = $siblings->[$idx+1] if $siblings && $idx >= 0;
 	if ($next) {
 		my $nmid = $next->{mid};
-		$rv .= $pad . $mapping->{$nmid}->[0];
+		$rv .= $pad . _skel_hdr($mapping, $nmid);
 		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->{mid}}->[0];
+			$rv .= $pad . _skel_hdr($mapping, $nn->{mid});
 		}
 	}
 	$rv .= $pad ."<a\nhref=#r$id>$s_s, $s_c; $ctx->{s_nr}</a>\n";
@@ -382,7 +400,7 @@ sub next_in_queue ($$) {
 
 sub stream_thread_i { # PublicInbox::WwwStream::getline callback
 	my ($ctx, $eml) = @_;
-	goto &thread_eml_entry if $eml; # tail recursion
+	return thread_eml_entry($ctx, $eml) if $eml;
 	return unless exists($ctx->{skel});
 	my $ghost_ok = $ctx->{nr}++;
 	while (1) {
@@ -416,25 +434,36 @@ sub stream_thread ($$) {
 # /$INBOX/$MSGID/t/ and /$INBOX/$MSGID/T/
 sub thread_html {
 	my ($ctx) = @_;
+	$ctx->{-upfx} = '../../';
 	my $mid = $ctx->{mid};
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	my ($nr, $msgs) = $ibx->over->get_thread($mid);
 	return missing_thread($ctx) if $nr == 0;
+
+	# link $INBOX_DIR/description text to "index_topics" view around
+	# the newest message in this thread
+	my $t = ts2str($ctx->{-t_max} = max(map { delete $_->{ts} } @$msgs));
+	my $t_fmt = fmt_ts($ctx->{-t_max});
+
 	my $skel = '<hr><pre>';
 	$skel .= $nr == 1 ? 'only message in thread' : 'end of thread';
-	$skel .= ", back to <a\nhref=\"../../\">index</a>\n\n";
+	$skel .= <<EOF;
+, other threads:[<a
+href="../../?t=$t">~$t_fmt UTC</a> | <a
+href="../../">newest</a>]
+
+EOF
 	$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->{skel} = \$skel;
 	$ctx->{prev_attr} = '';
 	$ctx->{prev_level} = 0;
-	$ctx->{root_anchor} = anchor_for($mid);
-	$ctx->{mapping} = {};
+	$ctx->{root_anchor} = 'm' . id_compress($mid, 1);
+	$ctx->{mapping} = {}; # mid -> [ header_summary, node, idx, level ]
 	$ctx->{s_nr} = ($nr > 1 ? "$nr+ messages" : 'only message')
 	               .' in thread';
 
@@ -503,7 +532,8 @@ sub attach_link ($$$$;$) {
 	return unless $part->{bdy};
 
 	my $nl = $idx eq '1' ? '' : "\n"; # like join("\n", ...)
-	my $size = bytes::length($part->body);
+	my $size = length($part->body);
+	delete $part->{bdy}; # save memory
 
 	# hide attributes normally, unless we want to aid users in
 	# spotting MUA problems:
@@ -539,7 +569,7 @@ EOF
 sub add_text_body { # callback for each_part
 	my ($p, $ctx) = @_;
 	my $upfx = $ctx->{mhref};
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	my $l = $ctx->{-linkify} //= PublicInbox::Linkify->new;
 	# $p - from each_part: [ Email::MIME-like, depth, $idx ]
 	my ($part, $depth, $idx) = @$p;
@@ -556,7 +586,7 @@ sub add_text_body { # callback for each_part
 
 	# makes no difference to browsers, and don't screw up filename
 	# link generation in diffs with the extra '%0D'
-	$s =~ s/\r\n/\n/sg;
+	$s =~ s/\r+\n/\n/sg;
 
 	# will be escaped to `&#8226;' in HTML
 	obfuscate_addrs($ibx, $s, "\x{2022}") if $ibx->{obfuscate};
@@ -576,8 +606,9 @@ sub add_text_body { # callback for each_part
 		$diff = 1;
 		delete $ctx->{-long_path};
 		my $spfx;
-		if ($ibx->{-repo_objs}) {
-			if (index($upfx, '//') >= 0) { # absolute URL (Atom feeds)
+		# absolute URL (Atom feeds)
+		if ($ibx->{coderepo}) {
+			if (index($upfx, '//') >= 0) {
 				$spfx = $upfx;
 				$spfx =~ s!/([^/]*)/\z!/!;
 			} else {
@@ -594,9 +625,6 @@ sub add_text_body { # callback for each_part
 		$ctx->{-spfx} = $spfx;
 	};
 
-	# some editors don't put trailing newlines at the end:
-	$s .= "\n" unless $s =~ /\n\z/s;
-
 	# split off quoted and unquoted blocks:
 	my @sections = PublicInbox::MsgIter::split_quotes($s);
 	undef $s; # free memory
@@ -605,6 +633,7 @@ sub add_text_body { # callback for each_part
 		attach_link($ctx, $ct, $p, $fn, $err);
 		$$rv .= "\n";
 	}
+	delete $part->{bdy}; # save memory
 	foreach my $cur (@sections) {
 		if ($cur =~ /\A>/) {
 			# we use a <span> here to allow users to specify
@@ -624,19 +653,22 @@ sub add_text_body { # callback for each_part
 
 sub _msg_page_prepare_obuf {
 	my ($eml, $ctx) = @_;
-	my $over = $ctx->{-inbox}->over;
+	my $over = $ctx->{ibx}->over;
 	my $obfs_ibx = $ctx->{-obfs_ibx};
 	my $rv = '';
 	my $mids = mids_for_index($eml);
 	my $nr = $ctx->{nr}++;
 	if ($nr) { # unlikely
+		if ($ctx->{chash} eq content_hash($eml)) {
+			warn "W: BUG? @$mids not deduplicated properly\n";
+			return \$rv;
+		}
+		$rv .=
+"<pre>WARNING: multiple messages have this Message-ID\n</pre>";
 		$rv .= '<pre>';
 	} else {
 		$ctx->{first_hdr} = $eml->header_obj;
-		if ($ctx->{smsg}) {
-			$rv .=
-"<pre>WARNING: multiple messages have this Message-ID\n</pre>";
-		}
+		$ctx->{chash} = content_hash($eml) if $ctx->{smsg}; # reused MID
 		$rv .= "<pre\nid=b>"; # anchor for body start
 	}
 	$ctx->{-upfx} = '../' if $over;
@@ -678,7 +710,7 @@ sub _msg_page_prepare_obuf {
 	for my $v ($eml->header('Date')) {
 		$v = ascii_html($v);
 		obfuscate_addrs($obfs_ibx, $v) if $obfs_ibx; # possible :P
-		$rv .= "Date: $v\n";
+		$rv .= qq{Date: $v\t<a\nhref="#r">[thread overview]</a>\n};
 	}
 	if (!$nr) { # first (and only) message, common case
 		$ctx->{-title_html} = join(' - ', @title);
@@ -714,7 +746,7 @@ sub SKEL_EXPAND () {
 sub thread_skel ($$$) {
 	my ($skel, $ctx, $hdr) = @_;
 	my $mid = mids($hdr)->[0];
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	my ($nr, $msgs) = $ibx->over->get_thread($mid);
 	my $parent = in_reply_to($hdr);
 	$$skel .= "\n<b>Thread overview: </b>";
@@ -723,7 +755,8 @@ sub thread_skel ($$$) {
 			$$skel .= SKEL_EXPAND."\n ";
 			$$skel .= ghost_parent('../', $parent) . "\n";
 		} else {
-			$$skel .= '[no followups] '.SKEL_EXPAND."\n";
+			$$skel .= "<a\nid=r>[no followups]</a> ".
+					SKEL_EXPAND."\n";
 		}
 		$ctx->{next_msg} = undef;
 		$ctx->{parent_msg} = $parent;
@@ -782,15 +815,22 @@ sub _parent_headers {
 	$rv;
 }
 
-# returns a string buffer via ->getline
+# returns a string buffer
 sub html_footer {
 	my ($ctx, $hdr) = @_;
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	my $upfx = '../';
-	my $skel = " <a\nhref=\"$upfx\">index</a>";
+	my $skel;
 	my $rv = '<pre>';
 	if ($ibx->over) {
-		$skel .= "\n";
+		my $t = ts2str($ctx->{-t_max});
+		my $t_fmt = fmt_ts($ctx->{-t_max});
+		$skel .= <<EOF;
+	other threads:[<a
+href="$upfx?t=$t">~$t_fmt UTC</a>|<a
+href="$upfx">newest</a>]
+EOF
+
 		thread_skel(\$skel, $ctx, $hdr);
 		my ($next, $prev);
 		my $parent = '       ';
@@ -821,6 +861,8 @@ sub html_footer {
 			$parent = " <a\nhref=\"$u\"\nrel=prev>parent</a>";
 		}
 		$rv .= "$next $prev$parent ";
+	} else { # unindexed inboxes w/o over
+		$skel = qq( <a\nhref="$upfx">latest</a>);
 	}
 	$rv .= qq(<a\nhref="#R">reply</a>);
 	$rv .= $skel;
@@ -835,11 +877,6 @@ sub linkify_ref_no_over {
 	"&lt;<a\nhref=\"../$href/\">$html</a>&gt;";
 }
 
-sub anchor_for {
-	my ($msgid) = @_;
-	'm' . id_compress($msgid, 1);
-}
-
 sub ghost_parent {
 	my ($upfx, $mid) = @_;
 
@@ -858,7 +895,7 @@ sub find_mid_root {
 	++$ctx->{root_idx} if $level == 0;
 	if ($node->{mid} eq $ctx->{mid}) {
 		$ctx->{found_mid_at} = $ctx->{root_idx};
-		return 0;
+		return 0; # stop iterating
 	}
 	1;
 }
@@ -941,7 +978,7 @@ sub skel_dump { # walk_thread callback
 		$$skel .= delete($ctx->{sl_note}) || '';
 	}
 
-	my $f = ascii_html($smsg->{from_name});
+	my $f = ascii_html(delete $smsg->{from_name});
 	my $obfs_ibx = $ctx->{-obfs_ibx};
 	obfuscate_addrs($obfs_ibx, $f) if $obfs_ibx;
 
@@ -1036,10 +1073,10 @@ sub _skel_ghost {
 }
 
 sub sort_ds {
-	[ sort {
+	@{$_[0]} = sort {
 		(eval { $a->topmost->{ds} } || 0) <=>
 		(eval { $b->topmost->{ds} } || 0)
-	} @{$_[0]} ];
+	} @{$_[0]};
 }
 
 # accumulate recent topics if search is supported
@@ -1048,7 +1085,7 @@ sub acc_topic { # walk_thread callback
 	my ($ctx, $level, $smsg) = @_;
 	my $mid = $smsg->{mid};
 	my $has_blob = $smsg->{blob} // do {
-		if (my $by_mid = $ctx->{-inbox}->smsg_by_mid($mid)) {
+		if (my $by_mid = $ctx->{ibx}->smsg_by_mid($mid)) {
 			%$smsg = (%$smsg, %$by_mid);
 			1;
 		}
@@ -1092,7 +1129,7 @@ sub dump_topics {
 	}
 
 	my @out;
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	my $obfs_ibx = $ibx->{obfuscate} ? $ibx : undef;
 
 	# sort by recency, this allows new posts to "bump" old topics...
@@ -1117,10 +1154,8 @@ sub dump_topics {
 			$anchor = '#t'; # thread skeleton
 		}
 
-		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/$anchor\">$top_subj</a>\n" .
-			" $ds UTC $n - $mbox / $atom\n";
+			" $ds UTC $n\n";
 		for (my $i = 0; $i < scalar(@extra); $i += 2) {
 			my $level = $extra[$i];
 			my $subj = $extra[$i + 1]; # already normalized
@@ -1142,22 +1177,18 @@ sub dump_topics {
 	200;
 }
 
-# only for the t= query parameter passed to overview DB
-sub ts2str ($) { strftime('%Y%m%d%H%M%S', gmtime($_[0])) };
-
 sub str2ts ($) {
 	my ($yyyy, $mon, $dd, $hh, $mm, $ss) = unpack('A4A2A2A2A2A2', $_[0]);
-	timegm($ss, $mm, $hh, $dd, $mon - 1, $yyyy);
+	timegm($ss || 0, $mm || 0, $hh || 0, $dd, $mon - 1, $yyyy);
 }
 
 sub pagination_footer ($$) {
 	my ($ctx, $latest) = @_;
-	delete $ctx->{qp} or return;
 	my $next = $ctx->{next_page} || '';
 	my $prev = $ctx->{prev_page} || '';
-	if ($prev) {
-		$next = $next ? "$next " : '     ';
-		$prev .= qq! <a\nhref='$latest'>latest</a>!;
+	if ($prev) {  # aligned padding for: 'next (older) | '
+		$next = $next ? "$next | " : '             | ';
+		$prev .= qq[ | <a\nhref="$latest">latest</a>];
 	}
 	"<hr><pre>page: $next$prev</pre>";
 }
@@ -1174,7 +1205,7 @@ sub paginate_recent ($$) {
 	$t =~ s/\A([0-9]{8,14})-// and $after = str2ts($1);
 	$t =~ /\A([0-9]{8,14})\z/ and $before = str2ts($1);
 
-	my $ibx = $ctx->{-inbox};
+	my $ibx = $ctx->{ibx};
 	my $msgs = $ibx->recent($opts, $after, $before);
 	my $nr = scalar @$msgs;
 	if ($nr < $lim && defined($after)) {
@@ -1195,15 +1226,18 @@ sub paginate_recent ($$) {
 	}
 	if (defined($oldest) && $more) {
 		my $s = ts2str($oldest);
-		$ctx->{next_page} = qq!<a\nhref="?t=$s"\nrel=next>next</a>!;
+		$ctx->{next_page} = qq[<a\nhref="?t=$s"\nrel=next>] .
+					'next (older)</a>';
 	}
 	if (defined($newest) && (defined($before) || defined($after))) {
 		my $s = ts2str($newest);
-		$ctx->{prev_page} = qq!<a\nhref="?t=$s-"\nrel=prev>prev</a>!;
+		$ctx->{prev_page} = qq[<a\nhref="?t=$s-"\nrel=prev>] .
+					'prev (newer)</a>';
 	}
 	$msgs;
 }
 
+# GET /$INBOX - top-level inbox view for indexed inboxes
 sub index_topics {
 	my ($ctx) = @_;
 	my $msgs = paginate_recent($ctx, 200); # 200 is our window
@@ -1241,7 +1275,7 @@ sub thread_adj_level {
 sub ghost_index_entry {
 	my ($ctx, $level, $node) = @_;
 	my ($beg, $end) = thread_adj_level($ctx,  $level);
-	$beg . '<pre>'. ghost_parent($ctx->{-upfx}, $node->{mid})
+	$beg . '<pre>'. ghost_parent($ctx->{-upfx}, $node->{mid} // '?')
 		. '</pre>' . $end;
 }