[PATCH] searchidx: fix -Lmedium for IDs and filenames

[Eric Wong <e@80x24.org>]

This fixes "m:", "l:", "dfn:", and "n:" search prefixes under
indexlevel=medium when mixed with indexlevel=full inboxish.
We need positional data for Message-IDs, List-Id, and filenames
for exact matches, though we still want to support wildcards.

Fortunately the storage cost is still small as these prefixes
tend to be small compared to message bodies.  These are NOT
boolean terms since wildcard support and partial matching is
desired.
---
 I noticed this while I was working on another patch, and
 it took forever to figure out why m: wasn't working for me.

 lib/PublicInbox/SearchIdx.pm | 47 ++++++++++++++++++++++++++++--------
 t/lei_xsearch.t              | 31 ++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 10 deletions(-)

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 3372bea5..772f5a64 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -22,6 +22,7 @@ use PublicInbox::OverIdx;
 use PublicInbox::Spawn qw(spawn nodatacow_dir);
 use PublicInbox::Git qw(git_unquote);
 use PublicInbox::MsgTime qw(msg_timestamp msg_datestamp);
+use PublicInbox::Address;
 our @EXPORT_OK = qw(log2stack is_ancestor check_size prepare_stack
 	index_text term_generator add_val is_bad_blob);
 my $X = \%PublicInbox::Search::X;
@@ -158,22 +159,44 @@ sub term_generator ($) { # write-only
 	}
 }
 
+sub index_phrase ($$$$) {
+	my ($self, $text, $wdf_inc, $prefix) = @_;
+
+	my $tg = term_generator($self);
+	$tg->index_text($text, $wdf_inc, $prefix);
+	$tg->increase_termpos;
+}
+
 sub index_text ($$$$) {
 	my ($self, $text, $wdf_inc, $prefix) = @_;
-	my $tg = term_generator($self); # man Search::Xapian::TermGenerator
 
 	if ($self->{indexlevel} eq 'full') {
-		$tg->index_text($text, $wdf_inc, $prefix);
-		$tg->increase_termpos;
+		index_phrase($self, $text, $wdf_inc, $prefix);
 	} else {
+		my $tg = term_generator($self);
 		$tg->index_text_without_positions($text, $wdf_inc, $prefix);
 	}
 }
 
 sub index_headers ($$) {
 	my ($self, $smsg) = @_;
-	my @x = (from => 'A', # Author
-		subject => 'S', to => 'XTO', cc => 'XCC');
+	my @x = (from => 'A', to => 'XTO', cc => 'XCC'); # A: Author
+	while (my ($field, $pfx) = splice(@x, 0, 2)) {
+		my $val = $smsg->{$field};
+		next if $val eq '';
+		# include "(comments)" after the address, too, so not using
+		# PublicInbox::Address::names or pairs
+		index_text($self, $val, 1, $pfx);
+
+		# we need positional info for email addresses since they
+		# can be considered phrases
+		if ($self->{indexlevel} eq 'medium') {
+			for my $addr (PublicInbox::Address::emails($val)) {
+				index_phrase($self, $addr, 1, $pfx);
+			}
+		}
+	}
+	@x = (subject => 'S');
 	while (my ($field, $pfx) = splice(@x, 0, 2)) {
 		my $val = $smsg->{$field};
 		index_text($self, $val, 1, $pfx) if $val ne '';
@@ -186,7 +209,11 @@ sub index_diff_inc ($$$$) {
 		index_text($self, join("\n", @$xnq), 1, 'XNQ');
 		@$xnq = ();
 	}
-	index_text($self, $text, 1, $pfx);
+	if ($pfx eq 'XDFN') {
+		index_phrase($self, $text, 1, $pfx);
+	} else {
+		index_text($self, $text, 1, $pfx);
+	}
 }
 
 sub index_old_diff_fn {
@@ -292,7 +319,7 @@ sub index_xapian { # msg_iter callback
 	my $ct = $part->content_type || 'text/plain';
 	my $fn = $part->filename;
 	if (defined $fn && $fn ne '') {
-		index_text($self, $fn, 1, 'XFN');
+		index_phrase($self, $fn, 1, 'XFN');
 	}
 	if ($part->{is_submsg}) {
 		my $mids = mids_for_index($part);
@@ -330,20 +357,20 @@ sub index_list_id ($$$) {
 		$l =~ /<([^>]+)>/ or next;
 		my $lid = lc $1;
 		$doc->add_boolean_term('G' . $lid);
-		index_text($self, $lid, 1, 'XL'); # probabilistic
+		index_phrase($self, $lid, 1, 'XL'); # probabilistic
 	}
 }
 
 sub index_ids ($$$$) {
 	my ($self, $doc, $hdr, $mids) = @_;
 	for my $mid (@$mids) {
-		index_text($self, $mid, 1, 'XM');
+		index_phrase($self, $mid, 1, 'XM');
 
 		# because too many Message-IDs are prefixed with
 		# "Pine.LNX."...
 		if ($mid =~ /\w{12,}/) {
 			my @long = ($mid =~ /(\w{3,}+)/g);
-			index_text($self, join(' ', @long), 1, 'XM');
+			index_phrase($self, join(' ', @long), 1, 'XM');
 		}
 	}
 	$doc->add_boolean_term('Q' . $_) for @$mids;
diff --git a/t/lei_xsearch.t b/t/lei_xsearch.t
index f865ff43..5bfbcfe6 100644
--- a/t/lei_xsearch.t
+++ b/t/lei_xsearch.t
@@ -78,4 +78,35 @@ is(scalar(@ibxish), scalar(@ibx) + 1, 'got locals back');
 is($lxs->search, $lxs, '->search works');
 is($lxs->over, undef, '->over fails');
 
+{
+	$lxs = PublicInbox::LeiXSearch->new;
+	my $v2ibx = PublicInbox::InboxWritable->new({
+		inboxdir => "$home/v2full",
+		name => 'v2full',
+		version => 2,
+		indexlevel => 'full',
+		-primary_address => 'v2full@example.com',
+	}, {});
+	my $im = $v2ibx->importer(0);
+	$im->add(eml_load('t/plack-qp.eml'));
+	$im->done;
+	my $v1ibx = PublicInbox::InboxWritable->new({
+		inboxdir => "$home/v1medium",
+		name => 'v1medium',
+		version => 1,
+		indexlevel => 'medium',
+		-primary_address => 'v1medium@example.com',
+	}, {});
+	$im = $v1ibx->importer(0);
+	$im->add(eml_load('t/utf8.eml'));
+	$im->done;
+	$lxs->prepare_external($v1ibx);
+	$lxs->prepare_external($v2ibx);
+	for my $loc ($lxs->locals) {
+		$lxs->attach_external($loc);
+	}
+	my $mset = $lxs->mset('m:testmessage@example.com');
+	is($mset->size, 1, 'got m: match on medium+full XSearch mix');
+}
+
 done_testing;