content_id: use `mids' and `references' for MID extraction

These already take care of deduping internally, so we'll save
ourselves at least some of the trouble while using a more
consistent API.  While we're at it, hash the header name as
well, since we need to distinguish which header a certain value
came from.

diff --git a/lib/PublicInbox/ContentId.pm b/lib/PublicInbox/ContentId.pm
index 7ec638ca5ef2ece2eb95912d126338e22f851d3b..d1a009e77f2ed9e9e8b4de30a79f85a706ef37e8 100644 (file)
--- a/lib/PublicInbox/ContentId.pm
+++ b/lib/PublicInbox/ContentId.pm
@@ -6,6 +6,7 @@ use strict;
 use warnings;
 use base qw/Exporter/;
 our @EXPORT_OK = qw/content_id/;
+use PublicInbox::MID qw(mids references);
 
 # not sure if less-widely supported hash families are worth bothering with
 use Digest::SHA;
@@ -22,20 +23,18 @@ sub content_id ($;$) {
        # References: and In-Reply-To: get used interchangeably
        # in some "duplicates" in LKML.  We treat them the same
        # in SearchIdx, so treat them the same for this:
-       my @mid = $hdr->header_raw('Message-ID');
-       @mid = (join(' ', @mid) =~ /<([^>]+)>/g);
-       my $refs = join(' ', $hdr->header_raw('References'),
-                       $hdr->header_raw('In-Reply-To'));
-       my @refs = ($refs =~ /<([^>]+)>/g);
        my %seen;
-       foreach my $mid (@mid, @refs) {
-               next if $seen{$mid};
-               $dig->add($mid);
+       foreach my $mid (@{mids($hdr)}) {
+               $dig->add('mid: '.$mid);
                $seen{$mid} = 1;
        }
+       foreach my $mid (@{references($hdr)}) {
+               next if $seen{$mid};
+               $dig->add('ref: '.$mid);
+       }
        foreach my $h (@ID_HEADERS) {
                my @v = $hdr->header_raw($h);
-               $dig->add($_) foreach @v;
+               $dig->add("$h: $_") foreach @v;
        }
        $dig->add($mime->body_raw);
        'SHA-' . $dig->algorithm . ':' . $dig->hexdigest;