inbox: simplify filtering for duplicate NNTP URLs

And add a note to remind ourselves to use List::Util::uniq
when it becomes common.

1 files changed, 5 insertions, 6 deletions

diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index e834d565..07e8b5b7 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -293,12 +293,11 @@ sub nntp_url {
                                 # nntp://news.example.com/alt.example
                                 push @m, $u;
                         }
-                        my %seen = map { $_ => 1 } @urls;
-                        foreach my $u (@m) {
-                                next if $seen{$u};
-                                $seen{$u} = 1;
-                                push @urls, $u;
-                        }
+
+                        # List::Util::uniq requires Perl 5.26+, maybe we
+                        # can use it by 2030 or so
+                        my %seen;
+                        @urls = grep { !$seen{$_}++ } (@urls, @m);
                 }
                 \@urls;
         };