view: avoid deduping a single word in subject skeletons

It is usually pointless to replace a single word with a '"' character.

1 files changed, 21 insertions, 15 deletions

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 41f1321e..81e83d97 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -755,6 +755,25 @@ sub _msg_date {
 
 sub fmt_ts { POSIX::strftime('%Y-%m-%d %k:%M', gmtime($_[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);
@@ -798,13 +817,7 @@ sub skel_dump {
         # so we do not show redundant text at the end.
         my $prev_subj = $ctx->{prev_subj} || [];
         $ctx->{prev_subj} = [ @subj ];
-        my $omit = ''; # '"' denotes identical text omitted
-        while (@$prev_subj && @subj && $subj[-1] eq $prev_subj->[-1]) {
-                pop @$prev_subj;
-                pop @subj;
-                $omit ||= '" ';
-        }
-        pop @subj if @subj && $subj[-1] =~ /^re:\s*/i;
+        my $omit = dedupe_subject($prev_subj, \@subj, '" ');
         my $end;
         if (@subj) {
                 my $subj = join(' ', @subj);
@@ -944,14 +957,7 @@ sub dump_topics {
                         $mid = delete $seen->{$subj};
                         my @subj = split(/ /, $srch->subject_normalized($subj));
                         my @next_prev = @subj; # full copy
-                        my $omit = ''; # '"' denotes identical text omitted
-                        while (@$prev_subj && @subj &&
-                                        $subj[-1] eq $prev_subj->[-1]) {
-                                pop @$prev_subj;
-                                pop @subj;
-                                $omit ||= ' "';
-                        }
-                        pop @subj if @subj && $subj[-1] =~ /^re:\s*/i;
+                        my $omit = dedupe_subject($prev_subj, \@subj, ' "');
                         $prev_subj = \@next_prev;
                         $subj = ascii_html(join(' ', @subj));
                         obfuscate_addrs($obfs_ibx, $subj) if $obfs_ibx;