lib/PublicInbox/Search.pm    | 25 +++++++++++++++++++++++++
 lib/PublicInbox/SearchMsg.pm |  3 +--
 t/search.t                   | 17 +++++++++++++++++

diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index bcc5312555d369d8f96c57fd026c662e623477d4..5ef380e86f2dc1816d0d3e6c4aca77e856aa8cf2 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -237,6 +237,31 @@ 	$subj =~ s/$REPLY_RE//igo; # remove reply prefix
 	$subj;
 }
 
+# for doc data
+sub subject_summary {
+	my $subj = pop;
+	my $max = 68;
+	if (length($subj) > $max) {
+		my @subj = split(/\s+/, $subj);
+		$subj = '';
+		my $l;
+
+		while ($l = shift @subj) {
+			my $new = $subj . $l . ' ';
+			last if length($new) >= $max;
+			$subj = $new;
+		}
+		if (length $subj) {
+			my $r = scalar @subj ? ' ...' : '';
+			$subj =~ s/ \z/$r/s;
+		} else {
+			@subj = ($l =~ /\A(.{1,72})/);
+			$subj = $subj[0] . ' ...';
+		}
+	}
+	$subj;
+}
+
 sub enquire {
 	my ($self) = @_;
 	$self->{enquire} ||= Search::Xapian::Enquire->new($self->{xdb});
diff --git a/lib/PublicInbox/SearchMsg.pm b/lib/PublicInbox/SearchMsg.pm
index a8f99bd5756d51179e9b7e998967ad755571907a..a9f3180b827e9c8aac8351671dce988d9b08459e 100644
--- a/lib/PublicInbox/SearchMsg.pm
+++ b/lib/PublicInbox/SearchMsg.pm
@@ -94,9 +94,8 @@ }
 
 sub to_doc_data {
 	my ($self) = @_;
-
 	$self->mid . "\n" .
-	$self->subject . "\n" .
+	PublicInbox::Search::subject_summary($self->subject) . "\n" .
 	$self->from_name . "\n".
 	$self->date . "\n" .
 	$self->references_sorted;
diff --git a/t/search.t b/t/search.t
index 17e9eaf43aea8e764de4e618539d7108e0947e43..65539f14c2ca31eb5ae97258360080602a97067b 100644
--- a/t/search.t
+++ b/t/search.t
@@ -16,6 +16,23 @@ is(0, system(qw(git init -q --bare), $git_dir), "git init (main)");
 eval { PublicInbox::Search->new($git_dir) };
 ok($@, "exception raised on non-existent DB");
 
+{
+	my $orig = "FOO " x 30;
+	my $summ = PublicInbox::Search::subject_summary($orig);
+
+	$summ = length($summ);
+	$orig = length($orig);
+	ok($summ < $orig && $summ > 0, "summary shortened ($orig => $summ)");
+
+	$orig = "FOO" x 30;
+	$summ = PublicInbox::Search::subject_summary($orig);
+
+	$summ = length($summ);
+	$orig = length($orig);
+	ok($summ < $orig && $summ > 0,
+	   "summary shortened but not empty: $summ");
+}
+
 my $rw = PublicInbox::SearchIdx->new($git_dir, 1);
 my $ro = PublicInbox::Search->new($git_dir);
 my $rw_commit = sub {