descend into message/(rfc822|news|global) parts

Email::MIME never supported this properly, but there's real
instances of forwarded messages as message/rfc822 attachments.
message/news is legacy thing which we'll see in archives, and
message/global appears to be the new thing.

gmime also supports message/rfc2822, so we'll support it anyways
despite lacking other evidence of its existence.

Existing attachments remain downloadable as a whole message,
but individual attachments of subparts are now downloadable
and can be displayed in HTML, too.

Furthermore, ensure Xapian can now search for common headers
inside those messages as well as the message bodies.

1 files changed, 25 insertions, 0 deletions

diff --git a/t/search.t b/t/search.t
index 6dd50474..9d74f5e0 100644
--- a/t/search.t
+++ b/t/search.t
@@ -479,6 +479,31 @@ EOF
         is_deeply($found, [], 'matched on phrase with l:');
 }
 
+$ibx->with_umask(sub {
+        $rw_commit->();
+        my $doc_id = $rw->add_message(eml_load('t/data/message_embed.eml'));
+        ok($doc_id > 0, 'messages within messages');
+        $rw->commit_txn_lazy;
+        $ro->reopen;
+        my $n_test_eml = $ro->query('n:test.eml');
+        is(scalar(@$n_test_eml), 1, 'got a result');
+        my $n_embed2x_eml = $ro->query('n:embed2x.eml');
+        is_deeply($n_test_eml, $n_embed2x_eml, '.eml filenames searchable');
+        for my $m (qw(20200418222508.GA13918@dcvr 20200418222020.GA2745@dcvr
+                        20200418214114.7575-1-e@yhbt.net)) {
+                is($ro->query("m:$m")->[0]->{mid},
+                        '20200418222508.GA13918@dcvr', 'probabilistic m:'.$m);
+                is($ro->query("mid:$m")->[0]->{mid},
+                        '20200418222508.GA13918@dcvr', 'boolean mid:'.$m);
+        }
+        is($ro->query('dfpost:4dc62c50')->[0]->{mid},
+                '20200418222508.GA13918@dcvr',
+                'diff search reaches inside message/rfc822');
+        is($ro->query('s:"mail header experiments"')->[0]->{mid},
+                '20200418222508.GA13918@dcvr',
+                'Subject search reaches inside message/rfc822');
+});
+
 done_testing();
 
 1;