remove postcodes entirely from indexing

place=postcode places are artificial places that collect addr:postcode
points for aggration. They should neither show up in the address nor
be searchable. That means that there is no need to index them at all.
Only let boundary=postal_code through which define correct areas for
postcodes.

sql/functions/placex_triggers.sql

@@ -581,6 +581,15 @@ BEGIN
     RETURN NEW;
   END IF;
 
+  -- Postcodes are just here to compute the centroids. They are not searchable
+  -- unless they are a boundary=postal_code.
+  -- There was an error in the style so that boundary=postal_code used to be
+  -- imported as place=postcode. That's why relations are allowed to pass here.
+  -- This can go away in a couple of versions.
+  IF NEW.class = 'place'  and NEW.type = 'postcode' and NEW.osm_type != 'R' THEN
+    RETURN NEW;
+  END IF;
+
   -- Speed up searches - just use the centroid of the feature
   -- cheaper but less acurate
   NEW.centroid := ST_PointOnSurface(NEW.geometry);

sql/functions/ranking.sql

@@ -145,10 +145,6 @@ BEGIN
   THEN
     SELECT * INTO search_rank, address_rank
       FROM get_postcode_rank(country, postcode);
-
-    IF NOT extended_type = 'A' THEN
-      address_rank := 0;
-    END IF;
   ELSEIF extended_type = 'N' AND place_class = 'highway' THEN
     search_rank = 30;
     address_rank = 0;