Merge branch 'learn'

* learn:
  doc: add public-inbox-learn(1) manpage
  mda: support multiple List-ID matches
  mda: prepare for multiple destinations
  inboxwritable: add assert_usable_dir sub
  mda: skip MIME parsing if spam
  mda: hoist out mda_filter_adjust
  filter/base: remove MAX_MID_SIZE constant
  mda: hoist out List-ID handling and reuse in -learn
  learn: hoist out remove_or_add subroutine
  learn: GIT_COMMITTER_<NAME|EMAIL> may be "" or "0"
  learn: update usage statement
  learn: only map recipient list on "ham" or "rm"
  learn: support multiple To/Cc headers

12 files changed, 269 insertions, 80 deletions

diff --git a/Documentation/include.mk b/Documentation/include.mk
index d2357ffc..bb622c1a 100644
--- a/Documentation/include.mk
+++ b/Documentation/include.mk
@@ -41,6 +41,7 @@ m1 += public-inbox-edit
 m1 += public-inbox-httpd
 m1 += public-inbox-index
 m1 += public-inbox-init
+m1 += public-inbox-learn
 m1 += public-inbox-mda
 m1 += public-inbox-nntpd
 m1 += public-inbox-watch
diff --git a/Documentation/public-inbox-learn.pod b/Documentation/public-inbox-learn.pod
new file mode 100644
index 00000000..b8190b59
--- /dev/null
+++ b/Documentation/public-inbox-learn.pod
@@ -0,0 +1,86 @@
+=head1 NAME
+
+public-inbox-learn - spam trainer and remover for public-inbox
+
+=head1 SYNOPSIS
+
+B<public-inbox-learn> <spam|ham|rm> E<lt>MESSAGE
+
+=head1 DESCRIPTION
+
+public-inbox-learn can remove spam or inject ham messages into
+an inbox while training a SpamAssassin instance.
+
+It is intended for users of L<public-inbox-mda(1)> or
+L<public-inbox-watch(1)>, but not users relying on
+L<git-fetch(1)> to mirror inboxes.
+
+It reads one message from standard input and operates on it
+depending on the command given:
+
+=head1 COMMANDS
+
+public-inbox-learn takes one of the following commands as its
+first and only argument:
+
+=over 8
+
+=item spam
+
+Treat the message as spam.  This will mark the message as
+removed so it becomes inaccessible via NNTP or WWW endpoints
+for all configured inboxes.
+
+The message remains accessible in git history.
+
+It will also be fed to L<spamc(1)> for training purposes unless
+C<publicinboxmda.spamcheck> is C<none> in L<public-inbox-config(5)>.
+
+=item ham
+
+Treat standard input as ham.  This is useful for manually injecting
+messages into the archives which failed the spam check run by
+L<public-inbox-mda(1)> or L<public-inbox-watch(1)>.
+
+It relies on the C<To:>, C<Cc:>, and C<List-ID:> headers
+to match configured inbox addresses and C<listid> directives.
+
+It will also be fed to L<spamc(1)> for training purposes unless
+C<publicinboxmda.spamcheck> is C<none> in L<public-inbox-config(5)>.
+
+=item rm
+
+This is identical to the C<spam> command above, but does
+not feed the message to L<spamc(1)>
+
+=back
+
+=head1 ENVIRONMENT
+
+=over 8
+
+=item PI_CONFIG
+
+Per-user config file parseable by L<git-config(1)>.
+See L<public-inbox-config(5)>.
+
+Default: ~/.public-inbox/config
+
+=back
+
+=head1 CONTACT
+
+Feedback welcome via plain-text mail to L<mailto:meta@public-inbox.org>
+
+The mail archives are hosted at L<https://public-inbox.org/meta/>
+and L<http://hjrcffqmbrq6wope.onion/meta/>
+
+=head1 COPYRIGHT
+
+Copyright 2019 all contributors L<mailto:meta@public-inbox.org>
+
+License: AGPL-3.0+ L<https://www.gnu.org/licenses/agpl-3.0.txt>
+
+=head1 SEE ALSO
+
+L<spamc(1)>, L<public-inbox-mda(1)>, L<public-inbox-watch(1)>
diff --git a/MANIFEST b/MANIFEST
index 7d2ac17c..d1b6749a 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -22,6 +22,7 @@ Documentation/public-inbox-edit.pod
 Documentation/public-inbox-httpd.pod
 Documentation/public-inbox-index.pod
 Documentation/public-inbox-init.pod
+Documentation/public-inbox-learn.pod
 Documentation/public-inbox-mda.pod
 Documentation/public-inbox-nntpd.pod
 Documentation/public-inbox-overview.pod
diff --git a/lib/PublicInbox/Filter/Base.pm b/lib/PublicInbox/Filter/Base.pm
index 052cd332..7a0c720f 100644
--- a/lib/PublicInbox/Filter/Base.pm
+++ b/lib/PublicInbox/Filter/Base.pm
@@ -6,7 +6,6 @@ package PublicInbox::Filter::Base;
 use strict;
 use warnings;
 use PublicInbox::MsgIter;
-use constant MAX_MID_SIZE => 244; # max term size - 1 in Xapian
 
 sub No ($) { "*** We only accept plain-text mail, No $_[0] ***" }
 
diff --git a/lib/PublicInbox/InboxWritable.pm b/lib/PublicInbox/InboxWritable.pm
index ab7b0ed5..9eab394d 100644
--- a/lib/PublicInbox/InboxWritable.pm
+++ b/lib/PublicInbox/InboxWritable.pm
@@ -30,12 +30,19 @@ sub new {
         $self;
 }
 
+sub assert_usable_dir {
+        my ($self) = @_;
+        my $dir = $self->{inboxdir};
+        return $dir if defined($dir) && $dir ne '';
+        die "no inboxdir defined for $self->{name}\n";
+}
+
 sub init_inbox {
         my ($self, $shards, $skip_epoch, $skip_artnum) = @_;
         # TODO: honor skip_artnum
         my $v = $self->{version} || 1;
         if ($v == 1) {
-                my $dir = $self->{inboxdir} or die "no inboxdir in inbox\n";
+                my $dir = assert_usable_dir($self);
                 PublicInbox::Import::init_bare($dir);
         } else {
                 my $v2w = importer($self);
diff --git a/lib/PublicInbox/MDA.pm b/lib/PublicInbox/MDA.pm
index 9cafda13..b0dfac45 100644
--- a/lib/PublicInbox/MDA.pm
+++ b/lib/PublicInbox/MDA.pm
@@ -83,4 +83,25 @@ sub set_list_headers {
         }
 }
 
+sub inboxes_for_list_id ($$) {
+        my ($klass, $config, $simple) = @_;
+
+        # newer Email::Simple allows header_raw, as does Email::MIME:
+        my @list_ids = $simple->can('header_raw') ?
+                        $simple->header_raw('List-Id') :
+                        $simple->header('List-Id');
+        my @dests;
+        for my $list_id (@list_ids) {
+                $list_id =~ /<[ \t]*(.+)?[ \t]*>/ or next;
+                if (my $ibx = $config->lookup_list_id($1)) {
+                        push @dests, $ibx;
+                }
+        }
+        if (scalar(@list_ids) > 1) {
+                warn "W: multiple List-IDs in message:\n";
+                warn "W: List-ID: $_\n" for @list_ids
+        }
+        \@dests;
+}
+
 1;
diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index ad2e8e62..1825da2c 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -77,7 +77,8 @@ sub new {
         # $creat may be any true value, or 0/undef.  A hashref is true,
         # and $creat->{nproc} may be set to an integer
         my ($class, $v2ibx, $creat) = @_;
-        my $dir = $v2ibx->{inboxdir} or die "no inboxdir in inbox\n";
+        $v2ibx = PublicInbox::InboxWritable->new($v2ibx);
+        my $dir = $v2ibx->assert_usable_dir;
         unless (-d $dir) {
                 if ($creat) {
                         require File::Path;
@@ -86,8 +87,6 @@ sub new {
                         die "$dir does not exist\n";
                 }
         }
-
-        $v2ibx = PublicInbox::InboxWritable->new($v2ibx);
         $v2ibx->umask_prepare;
 
         my $xpfx = "$dir/xap" . PublicInbox::Search::SCHEMA_VERSION;
diff --git a/script/public-inbox-learn b/script/public-inbox-learn
index c4c4d4b9..3073294a 100755..100644
--- a/script/public-inbox-learn
+++ b/script/public-inbox-learn
@@ -4,7 +4,7 @@
 #
 # Used for training spam (via SpamAssassin) and removing messages from a
 # public-inbox
-my $usage = "$0 (spam|ham) < /path/to/message";
+my $usage = "$0 <spam|ham|rm> </path/to/message";
 use strict;
 use warnings;
 use PublicInbox::Config;
@@ -39,47 +39,26 @@ my $mime = PublicInbox::MIME->new(eval {
         $data
 });
 
-# get all recipients
-my %dests;
-foreach my $h (qw(Cc To)) {
-        my $val = $mime->header($h) or next;
-        foreach my $email (PublicInbox::Address::emails($val)) {
-                $dests{lc($email)} = 1;
-        }
-}
-
-if ($train eq 'spam') {
-        $pi_config->each_inbox(sub {
-                my ($ibx) = @_;
-                $ibx = PublicInbox::InboxWritable->new($ibx);
-                my $im = $ibx->importer(0);
-                $im->remove($mime, 'spam');
-                $im->done;
-        });
-}
-
-require PublicInbox::MDA if $train eq "ham";
+sub remove_or_add ($$$) {
+        my ($ibx, $train, $addr) = @_;
 
-# n.b. message may be cross-posted to multiple public-inboxes
-foreach my $recipient (keys %dests) {
-        my $dst = $pi_config->lookup($recipient) or next;
         # We do not touch GIT_COMMITTER_* env here so we can track
         # who trained the message.
-        $dst->{name} = $ENV{GIT_COMMITTER_NAME} || $dst->{name};
-        $dst->{-primary_address} = $ENV{GIT_COMMITTER_EMAIL} || $recipient;
-        $dst = PublicInbox::InboxWritable->new($dst);
-        my $im = $dst->importer(0);
+        $ibx->{name} = $ENV{GIT_COMMITTER_NAME} // $ibx->{name};
+        $ibx->{-primary_address} = $ENV{GIT_COMMITTER_EMAIL} // $addr;
+        $ibx = PublicInbox::InboxWritable->new($ibx);
+        my $im = $ibx->importer(0);
 
-        if ($train eq "spam" || $train eq "rm") {
+        if ($train eq "rm") {
                 # This needs to be idempotent, as my inotify trainer
                 # may train for each cross-posted message, and this
                 # script already learns for every list in
                 # ~/.public-inbox/config
                 $im->remove($mime, $train);
-        } else { # $train eq "ham"
+        } elsif ($train eq "ham") {
                 # no checking for spam here, we assume the message has
                 # been reviewed by a human at this point:
-                PublicInbox::MDA->set_list_headers($mime, $dst);
+                PublicInbox::MDA->set_list_headers($mime, $ibx);
 
                 # Ham messages are trained when they're marked into
                 # a SEEN state, so this is idempotent:
@@ -88,6 +67,41 @@ foreach my $recipient (keys %dests) {
         $im->done;
 }
 
+# spam is removed from all known inboxes since it is often Bcc:-ed
+if ($train eq 'spam') {
+        $pi_config->each_inbox(sub {
+                my ($ibx) = @_;
+                $ibx = PublicInbox::InboxWritable->new($ibx);
+                my $im = $ibx->importer(0);
+                $im->remove($mime, 'spam');
+                $im->done;
+        });
+} else {
+        require PublicInbox::MDA;
+
+        # get all recipients
+        my %dests; # address => <PublicInbox::Inbox|0(false)>
+        for ($mime->header('Cc'), $mime->header('To')) {
+                foreach my $addr (PublicInbox::Address::emails($_)) {
+                        $addr = lc($addr);
+                        $dests{$addr} //= $pi_config->lookup($addr) // 0;
+                }
+        }
+
+        # n.b. message may be cross-posted to multiple public-inboxes
+        my %seen;
+        while (my ($addr, $ibx) = each %dests) {
+                next unless ref($ibx); # $ibx may be 0
+                next if $seen{"$ibx"}++;
+                remove_or_add($ibx, $train, $addr);
+        }
+        my $dests = PublicInbox::MDA->inboxes_for_list_id($pi_config, $mime);
+        for my $ibx (@$dests) {
+                next if !$seen{"$ibx"}++;
+                remove_or_add($ibx, $train, $ibx->{-primary_address});
+        }
+}
+
 if ($err) {
         warn $err;
         exit 1;
diff --git a/script/public-inbox-mda b/script/public-inbox-mda
index 584218b5..dca8a0ea 100755
--- a/script/public-inbox-mda
+++ b/script/public-inbox-mda
@@ -37,28 +37,38 @@ my $config = PublicInbox::Config->new;
 my $key = 'publicinboxmda.spamcheck';
 my $default = 'PublicInbox::Spamcheck::Spamc';
 my $spamc = PublicInbox::Spamcheck::get($config, $key, $default);
-my $dst;
+my $dests = [];
 my $recipient = $ENV{ORIGINAL_RECIPIENT};
 if (defined $recipient) {
-        $dst = $config->lookup($recipient); # first check
+        my $ibx = $config->lookup($recipient); # first check
+        push @$dests, $ibx if $ibx;
 }
-if (!defined $dst) {
-        my $list_id = $simple->header('List-Id');
-        if (defined $list_id && $list_id =~ /<[ \t]*(.+)?[ \t]*>/) {
-                $dst = $config->lookup_list_id($1);
-        }
-        if (!defined $dst && !defined $recipient) {
+if (!scalar(@$dests)) {
+        $dests = PublicInbox::MDA->inboxes_for_list_id($config, $simple);
+        if (!scalar(@$dests) && !defined($recipient)) {
                 die "ORIGINAL_RECIPIENT not defined in ENV\n";
         }
-        defined $dst or do_exit(67); # EX_NOUSER 5.1.1 user unknown
+        scalar(@$dests) or do_exit(67); # EX_NOUSER 5.1.1 user unknown
 }
-$dst->{inboxdir} or do_exit(67);
-$dst = PublicInbox::InboxWritable->new($dst);
 
-# pre-check, MDA has stricter rules than an importer might;
-if ($precheck && !PublicInbox::MDA->precheck($simple, $dst->{address})) {
-        do_exit(0);
-}
+my $err;
+@$dests = grep {
+        my $ibx = PublicInbox::InboxWritable->new($_);
+        eval { $ibx->assert_usable_dir };
+        if ($@) {
+                warn $@;
+                $err = 1;
+                0;
+        # pre-check, MDA has stricter rules than an importer might;
+        } elsif ($precheck) {
+                !!PublicInbox::MDA->precheck($simple, $ibx->{address});
+        } else {
+                1;
+        }
+} @$dests;
+
+do_exit(67) if $err && scalar(@$dests) == 0;
+
 $simple = undef;
 my $spam_ok;
 if ($spamc) {
@@ -74,39 +84,51 @@ if ($spamc) {
         my $fh = $emm->fh;
         read($fh, $str, -s $fh);
 }
-
-my $mime = PublicInbox::MIME->new(\$str);
 do_exit(0) unless $spam_ok;
 
-my $fcfg = $dst->{filter} || '';
-# -mda defaults to the strict base filter
-if ($fcfg eq '') {
-        $dst->{filter} = 'PublicInbox::Filter::Base';
-} elsif ($fcfg eq 'scrub') { # legacy alias, undocumented, remove?
-        $dst->{filter} = 'PublicInbox::Filter::Mirror';
+# -mda defaults to the strict base filter which we won't use anywhere else
+sub mda_filter_adjust ($) {
+        my ($ibx) = @_;
+        my $fcfg = $ibx->{filter} || '';
+        if ($fcfg eq '') {
+                $ibx->{filter} = 'PublicInbox::Filter::Base';
+        } elsif ($fcfg eq 'scrub') { # legacy alias, undocumented, remove?
+                $ibx->{filter} = 'PublicInbox::Filter::Mirror';
+        }
+}
+
+my @rejects;
+for my $ibx (@$dests) {
+        mda_filter_adjust($ibx);
+        my $filter = $ibx->filter;
+        my $mime = PublicInbox::MIME->new($str);
+        my $ret = $filter->delivery($mime);
+        if (ref($ret) && $ret->isa('Email::MIME')) { # filter altered message
+                $mime = $ret;
+        } elsif ($ret == PublicInbox::Filter::Base::IGNORE) {
+                next; # nothing, keep looping
+        } elsif ($ret == PublicInbox::Filter::Base::REJECT) {
+                push @rejects, $filter->err;
+                next;
+        }
+
+        PublicInbox::MDA->set_list_headers($mime, $ibx);
+        my $im = $ibx->importer(0);
+        if (defined $im->add($mime)) {
+                # ->abort is idempotent, no emergency if a single
+                # destination succeeds
+                $emm->abort;
+        } else { # v1-only
+                my $mid = $mime->header_obj->header_raw('Message-ID');
+                # this message is similar to what ssoma-mda shows:
+                print STDERR "CONFLICT: Message-ID: $mid exists\n";
+        }
+        $im->done;
 }
-my $filter = $dst->filter;
-my $ret = $filter->delivery($mime);
-if (ref($ret) && $ret->isa('Email::MIME')) { # filter altered message
-        $mime = $ret;
-} elsif ($ret == PublicInbox::Filter::Base::IGNORE) {
-        do_exit(0); # chuck it to emergency
-} elsif ($ret == PublicInbox::Filter::Base::REJECT) {
-        $! = 65; # EX_DATAERR 5.6.0 data format error
-        die $filter->err, "\n";
-} # else { accept
-$filter = undef;
 
-PublicInbox::MDA->set_list_headers($mime, $dst);
-my $im = $dst->importer(0);
-if (defined $im->add($mime)) {
-        $emm = $emm->abort;
-} else {
-        # this message is similar to what ssoma-mda shows:
-        print STDERR "CONFLICT: Message-ID: ",
-                        $mime->header_obj->header_raw('Message-ID'),
-                        " exists\n";
+if (scalar(@rejects) && scalar(@rejects) == scalar(@$dests)) {
+        $! = 65; # EX_DATAERR 5.6.0 data format error
+        die join("\n", @rejects, '');
 }
 
-$im->done;
 do_exit(0);
diff --git a/t/import.t b/t/import.t
index 4ec3c4f3..d309eec5 100644
--- a/t/import.t
+++ b/t/import.t
@@ -96,4 +96,12 @@ is(undef, $im->checkpoint, 'checkpoint works before ->done');
 $im->done;
 is(undef, $im->checkpoint, 'checkpoint works after ->done');
 $im->checkpoint;
+
+my $nogit = PublicInbox::Git->new("$dir/non-existent/dir");
+eval {
+        my $nope = PublicInbox::Import->new($nogit, 'nope', 'no@example.com');
+        $nope->add($mime);
+};
+ok($@, 'Import->add fails on non-existent dir');
+
 done_testing();
diff --git a/t/mda.t b/t/mda.t
index 99592b2d..35811ac6 100644
--- a/t/mda.t
+++ b/t/mda.t
@@ -308,6 +308,25 @@ EOF
         my $cur = `git --git-dir=$maindir diff HEAD~1..HEAD`;
         like($cur, qr/this message would not be accepted without --no-precheck/,
                 '--no-precheck delivered message anyways');
+
+        # try a message with multiple List-ID headers
+        $in = <<EOF;
+List-ID: <foo.bar>
+List-ID: <$list_id>
+Message-ID: <2lids\@example>
+Subject: two List-IDs
+From: user <user\@example.com>
+To: $addr
+Date: Fri, 02 Oct 1993 00:00:00 +0000
+
+EOF
+        ($out, $err) = ('', '');
+        IPC::Run::run([$mda], \$in, \$out, \$err);
+        is($?, 0, 'mda OK with multiple List-Id matches');
+        $cur = `git --git-dir=$maindir diff HEAD~1..HEAD`;
+        like($cur, qr/Message-ID: <2lids\@example>/,
+                'multi List-ID match delivered');
+        like($err, qr/multiple List-ID/, 'warned about multiple List-ID');
 }
 
 done_testing();
diff --git a/t/v2writable.t b/t/v2writable.t
index 2b825768..bfe17d0a 100644
--- a/t/v2writable.t
+++ b/t/v2writable.t
@@ -276,4 +276,16 @@ EOF
         $im->done;
 }
 
+my $tmp = {
+        inboxdir => "$inboxdir/non-existent/subdir",
+        name => 'nope',
+        version => 2,
+        -primary_address => 'test@example.com',
+};
+eval {
+        my $nope = PublicInbox::V2Writable->new($tmp);
+        $nope->add($mime);
+};
+ok($@, 'V2Writable fails on non-existent dir');
+
 done_testing();