[PATCH 1/2] imap: reinstate non-UID SEARCH

[Eric Wong <e@yhbt.net>]

Since we support MSNs properly, now, it seems acceptable
to support regular SEARCH requests in case there are any
clients which still use non-UID SEARCH.
---
 lib/PublicInbox/IMAP.pm | 35 ++++++++++++++++++++++++++---------
 t/imapd.t               | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 373bffc18d9..4631ea7eabc 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -1086,14 +1086,23 @@ sub parse_date ($) { # 02-Oct-1993
 	timegm(0, 0, 0, $dd, $mm, $yyyy);
 }
 
+sub msn_convert ($$) {
+	my ($self, $uids) = @_;
+	my $adj = $self->{uid_base} + 1;
+	my $uo2m = uo2m_extend($self, $uids->[-1]);
+	$uo2m = [ unpack('S*', $uo2m) ] if !ref($uo2m);
+	$_ = $uo2m->[$_ - $adj] for @$uids;
+}
+
 sub search_uid_range { # long_response
-	my ($self, $tag, $sql, $range_info) = @_;
+	my ($self, $tag, $sql, $range_info, $want_msn) = @_;
 	my $uids = [];
 	if (defined(my $err = refill_uids($self, $uids, $range_info, $sql))) {
 		$err ||= 'OK Search done';
 		$self->write("\r\n$tag $err\r\n");
 		return;
 	}
+	msn_convert($self, $uids) if $want_msn;
 	$self->msg_more(join(' ', '', @$uids));
 	1; # more
 }
@@ -1256,38 +1265,46 @@ sub refill_xap ($$$$) {
 }
 
 sub search_xap_range { # long_response
-	my ($self, $tag, $q, $range_info) = @_;
+	my ($self, $tag, $q, $range_info, $want_msn) = @_;
 	my $uids = [];
 	if (defined(my $err = refill_xap($self, $uids, $range_info, $q))) {
 		$err ||= 'OK Search done';
 		$self->write("\r\n$tag $err\r\n");
 		return;
 	}
+	msn_convert($self, $uids) if $want_msn;
 	$self->msg_more(join(' ', '', @$uids));
 	1; # more
 }
 
-sub cmd_uid_search ($$$;) {
-	my ($self, $tag) = splice(@_, 0, 2);
+sub search_common {
+	my ($self, $tag, $rest, $want_msn) = @_;
 	my $ibx = $self->{ibx} or return "$tag BAD No mailbox selected\r\n";
-	my $q = parse_query($self, \@_);
+	my $q = parse_query($self, $rest);
 	return "$tag $q\r\n" if !ref($q);
 	my ($sql, $range_info) = delete @$q{qw(sql range_info)};
 	if (!scalar(keys %$q)) { # overview.sqlite3
 		$self->msg_more('* SEARCH');
 		long_response($self, \&search_uid_range,
-				$tag, $sql, $range_info);
+				$tag, $sql, $range_info, $want_msn);
 	} elsif ($q = $q->{xap}) {
 		$self->msg_more('* SEARCH');
 		long_response($self, \&search_xap_range,
-				$tag, $q, $range_info);
+				$tag, $q, $range_info, $want_msn);
 	} else {
 		"$tag BAD Error\r\n";
 	}
 }
 
-# note: MSN SEARCH is NOT supported.  Do any widely-used MUAs
-# rely on MSNs from SEARCH results?  Let us know at meta@public-inbox.org
+sub cmd_uid_search ($$$;) {
+	my ($self, $tag) = splice(@_, 0, 2);
+	search_common($self, $tag, \@_);
+}
+
+sub cmd_search ($$$;) {
+	my ($self, $tag) = splice(@_, 0, 2);
+	search_common($self, $tag, \@_, 1);
+}
 
 sub args_ok ($$) { # duplicated from PublicInbox::NNTP
 	my ($cb, $argc) = @_;
diff --git a/t/imapd.t b/t/imapd.t
index edfc52046d2..36082d8c7ee 100644
--- a/t/imapd.t
+++ b/t/imapd.t
@@ -367,6 +367,44 @@ is(scalar keys %$ret, 3, 'got all 3 messages with comma-separated sequence');
 $ret = $mic->fetch_hash('1:*', 'RFC822') or BAIL_OUT "FETCH $@";
 is(scalar keys %$ret, 3, 'got all 3 messages');
 
+SKIP: {
+	# do any clients use non-UID IMAP SEARCH?
+	skip 'Xapian missing', 2 if $level eq 'basic';
+	my $x = $mic->search('all');
+	is_deeply($x, [1, 2, 3], 'MSN SEARCH works before rm');
+	$x = $mic->search(qw(header subject embedded));
+	is_deeply($x, [2], 'MSN SEARCH on Subject works before rm');
+}
+
+{
+	my $rdr = { 0 => \($ret->{1}->{RFC822}) };
+	my $env = { HOME => $ENV{HOME} };
+	my @cmd = qw(-learn rm --all);
+	run_script(\@cmd, $env, $rdr) or BAIL_OUT('-learn rm');
+}
+
+SKIP: {
+	# do any clients use non-UID IMAP SEARCH?  We only ensure
+	# MSN "SEARCH" can return a result which can be retrieved
+	# via MSN "FETCH"
+	skip 'Xapian missing', 3 if $level eq 'basic';
+	my $x = $mic->search(qw(header subject embedded));
+	is(scalar(@$x), 1, 'MSN SEARCH on Subject works after rm');
+	$x = $mic->message_string($x->[0]);
+	is($x, $ret->{2}->{RFC822}, 'message 2 unchanged');
+}
+
+# FIXME? no EXPUNGE response, yet
+my $r2 = $mic->fetch_hash('1:*', 'BODY.PEEK[]') or BAIL_OUT "FETCH $@";
+is(scalar keys %$r2, 2, 'did not get all 3 messages');
+is($r2->{2}->{'BODY[]'}, $ret->{2}->{RFC822}, 'message 2 unchanged');
+is($r2->{3}->{'BODY[]'}, $ret->{3}->{RFC822}, 'message 3 unchanged');
+$r2 = $mic->fetch_hash(2, 'BODY.PEEK[HEADER.FIELDS (message-id)]')
+			or BAIL_OUT "FETCH $@";
+is($r2->{2}->{'BODY[HEADER.FIELDS (MESSAGE-ID)]'},
+	'Message-ID: <20200418222508.GA13918@dcvr>'."\r\n\r\n",
+	'BODY.PEEK[HEADER.FIELDS ...] drops .PEEK');
+
 {
 	my @new_list = $mic->list;
 	# tag differs in [-1]