1 files changed, 21 insertions, 1 deletions
diff --git a/lib/PublicInbox/Smsg.pm b/lib/PublicInbox/Smsg.pm
index c6ff7f52..2b72e8b5 100644
--- a/lib/PublicInbox/Smsg.pm
+++ b/lib/PublicInbox/Smsg.pm
@@ -12,7 +12,7 @@ use strict;
  use warnings;
  use base qw(Exporter);
  our @EXPORT_OK = qw(subject_normalized);
-use PublicInbox::MID qw(mids);
+use PublicInbox::MID qw(mids references);
  use PublicInbox::Address;
  use PublicInbox::MsgTime qw(msg_timestamp msg_datestamp);
  
@@ -69,6 +69,26 @@ sub psgi_cull ($) {
          $self;
  }
  
+sub parse_references ($$$) {
+        my ($smsg, $hdr, $mids) = @_;
+        my $refs = references($hdr);
+        push(@$refs, @$mids) if scalar(@$mids) > 1;
+        return $refs if scalar(@$refs) == 0;
+
+        # prevent circular references here:
+        my %seen = ( $smsg->{mid} => 1 );
+        my @keep;
+        foreach my $ref (@$refs) {
+                if (length($ref) > PublicInbox::MID::MAX_MID_SIZE) {
+                        warn "References: <$ref> too long, ignoring\n";
+                        next;
+                }
+                push(@keep, $ref) unless $seen{$ref}++;
+        }
+        $smsg->{references} = '<'.join('> <', @keep).'>' if @keep;
+        \@keep;
+}
+
  # used for v2, Import and v1 non-SQLite WWW code paths
  sub populate {
          my ($self, $hdr, $sync) = @_;