search: stop assuming Message-ID is unique

In general, they are, but there's no way for or general purpose
mail server to enforce that.  This is a step in allowing us
to handle more corner cases which existing lists throw at us.

3 files changed, 19 insertions, 7 deletions

diff --git a/lib/PublicInbox/ExtMsg.pm b/lib/PublicInbox/ExtMsg.pm
index 4e31ef0f..90d68db8 100644
--- a/lib/PublicInbox/ExtMsg.pm
+++ b/lib/PublicInbox/ExtMsg.pm
@@ -46,7 +46,7 @@ sub ext_msg {
                 }
 
                 # try to find the URL with Xapian to avoid forking
-                my $doc_id = eval { $s->find_unique_doc_id('XMID' . $mid) };
+                my $doc_id = eval { $s->find_first_doc_id('XMID' . $mid) };
                 if ($@) {
                         # xapian not configured properly for this repo
                         push @nox, $other;
diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index 3ec96ca9..33a1f2d3 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -56,7 +56,7 @@ my %bool_pfx_internal = (
 );
 
 my %bool_pfx_external = (
-        mid => 'XMID', # uniQue id (Message-ID)
+        mid => 'XMID', # Message-ID (full/exact)
 );
 
 my %prob_prefix = (
@@ -285,7 +285,7 @@ sub lookup_message {
         my ($self, $mid) = @_;
         $mid = mid_clean($mid);
 
-        my $doc_id = $self->find_unique_doc_id('XMID' . $mid);
+        my $doc_id = $self->find_first_doc_id('XMID' . $mid);
         my $smsg;
         if (defined $doc_id) {
                 # raises on error:
@@ -327,6 +327,16 @@ sub find_doc_ids {
         ($db->postlist_begin($termval), $db->postlist_end($termval));
 }
 
+sub find_first_doc_id {
+        my ($self, $termval) = @_;
+
+        my ($begin, $end) = $self->find_doc_ids($termval);
+
+        return undef if $begin->equal($end); # not found
+
+        $begin->get_docid;
+}
+
 # normalize subjects so they are suitable as pathnames for URLs
 # XXX: consider for removal
 sub subject_path {
diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index fa5057fd..265403a3 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -366,12 +366,14 @@ sub remove_message {
         $mid = mid_clean($mid);
 
         eval {
-                $doc_id = $self->find_unique_doc_id('XMID' . $mid);
-                if (defined $doc_id) {
-                        $db->delete_document($doc_id);
-                } else {
+                my ($head, $tail) = $self->find_doc_ids('XMID' . $mid);
+                if ($head->equal($tail)) {
                         warn "cannot remove non-existent <$mid>\n";
                 }
+                for (; $head != $tail; $head->inc) {
+                        my $docid = $head->get_docid;
+                        $db->delete_document($docid);
+                }
         };
 
         if ($@) {