+# Copyright (C) 2018 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+use strict;
+use warnings;
+use Test::More;
+use File::Temp qw/tempdir/;
+use PublicInbox::MIME;
+use PublicInbox::Config;
+use PublicInbox::WWW;
+my @mods = qw(DBD::SQLite Search::Xapian HTTP::Request::Common Plack::Test
+ URI::Escape Plack::Builder);
+foreach my $mod (@mods) {
+ eval "require $mod";
+ plan skip_all => "$mod missing for psgi_v2_dupes.t" if $@;
+}
+use_ok($_) for @mods;
+use_ok 'PublicInbox::V2Writable';
+my $mainrepo = tempdir('pi-v2_dupes-XXXXXX', TMPDIR => 1, CLEANUP => 1);
+my $ibx = {
+ mainrepo => $mainrepo,
+ name => 'test-v2writable',
+ version => 2,
+ -primary_address => 'test@example.com',
+};
+$ibx = PublicInbox::Inbox->new($ibx);
+my $new_mid;
+
+my $im = PublicInbox::V2Writable->new($ibx, 1);
+$im->{parallel} = 0;
+
+my $mime = PublicInbox::MIME->create(
+ header => [
+ From => 'a@example.com',
+ To => 'test@example.com',
+ Subject => 'this is a subject',
+ 'Message-ID' => '<a-mid@b>',
+ Date => 'Fri, 02 Oct 1993 00:00:00 +0000',
+ ],
+ body => "hello world\n",
+);
+ok($im->add($mime), 'added one message');
+$mime->body_set("hello world!\n");
+
+my @warn;
+local $SIG{__WARN__} = sub { push @warn, @_ };
+ok($im->add($mime), 'added duplicate-but-different message');
+is(scalar(@warn), 1, 'got one warning');
+my @mids = $mime->header_obj->header_raw('Message-Id');
+$new_mid = PublicInbox::MID::mid_clean($mids[0]);
+$im->done;
+
+my $cfgpfx = "publicinbox.v2test";
+my %cfg = (
+ "$cfgpfx.address" => $ibx->{-primary_address},
+ "$cfgpfx.mainrepo" => $mainrepo,
+);
+
+my $config = PublicInbox::Config->new({ %cfg });
+my $www = PublicInbox::WWW->new($config);
+my ($res, $raw, @from_);
+test_psgi(sub { $www->call(@_) }, sub {
+ my ($cb) = @_;
+ $res = $cb->(GET('/v2test/a-mid@b/raw'));
+ $raw = $res->content;
+ like($raw, qr/^hello world$/m, 'got first message');
+ like($raw, qr/^hello world!$/m, 'got second message');
+ @from_ = ($raw =~ m/^From /mg);
+ is(scalar(@from_), 2, 'two From_ lines');
+
+ $res = $cb->(GET("/v2test/$new_mid/raw"));
+ $raw = $res->content;
+ like($raw, qr/^hello world!$/m, 'second message with new Message-Id');
+ @from_ = ($raw =~ m/^From /mg);
+ is(scalar(@from_), 1, 'only one From_ line');
+});
+
+$mime->header_set('Message-Id', 'a-mid@b');
+$mime->body_set("hello ghosts\n");
+ok($im->add($mime), 'added 3rd duplicate-but-different message');
+is(scalar(@warn), 2, 'got another warning');
+like($warn[0], qr/mismatched/, 'warned about mismatched messages');
+is($warn[0], $warn[1], 'both warnings are the same');
+
+@mids = $mime->header_obj->header_raw('Message-Id');
+my $third = PublicInbox::MID::mid_clean($mids[0]);
+$im->done;
+
+# need to reload...
+$config = PublicInbox::Config->new({ %cfg });
+$www = PublicInbox::WWW->new($config);
+test_psgi(sub { $www->call(@_) }, sub {
+ my ($cb) = @_;
+ $res = $cb->(GET("/v2test/$third/raw"));
+ $raw = $res->content;
+ like($raw, qr/^hello ghosts$/m, 'got third message');
+ @from_ = ($raw =~ m/^From /mg);
+ is(scalar(@from_), 1, 'one From_ line');
+
+ $res = $cb->(GET('/v2test/a-mid@b/raw'));
+ $raw = $res->content;
+ like($raw, qr/^hello world$/m, 'got first message');
+ like($raw, qr/^hello world!$/m, 'got second message');
+ like($raw, qr/^hello ghosts$/m, 'got third message');
+ @from_ = ($raw =~ m/^From /mg);
+ is(scalar(@from_), 3, 'three From_ lines');
+});
+
+done_testing();
+
+1;