save differing linked polace names in extra fields

This keeps the names tracable and ensures that all names are searchable
when they differ. Do not keep names when they are exactly the same
to save some space. Linked names are cleaned out before relinking.

lib-sql/functions/placex_triggers.sql

@@ -26,6 +26,7 @@ CREATE OR REPLACE FUNCTION placex_indexing_prepare(p placex)
 DECLARE
   location RECORD;
   result prepare_update_info;
+  extra_names HSTORE;
 BEGIN
   -- For POI nodes, check if the address should be derived from a surrounding
   -- building.
@@ -58,8 +59,11 @@ BEGIN
     END LOOP;
   END IF;
 
+  -- remove internal and derived names
   result.address := result.address - '_unlisted_place'::TEXT;
-  result.name := p.name;
+  SELECT hstore(array_agg(key), array_agg(value)) INTO result.name
+    FROM each(p.name) WHERE key not like '\_%';
+
   result.class := p.class;
   result.type := p.type;
   result.country_code := p.country_code;
@@ -72,8 +76,17 @@ BEGIN
   IF location.place_id is not NULL THEN
     result.linked_place_id := location.place_id;
 
-    IF NOT location.name IS NULL THEN
-      result.name := location.name || result.name;
+    IF location.name is not NULL THEN
+      {% if debug %}RAISE WARNING 'Names original: %, location: %', result.name, location.name;{% endif %}
+      -- Add all names from the place nodes that deviate from the name
+      -- in the relation with the prefix '_place_'. Deviation means that
+      -- either the value is different or a given key is missing completely
+      SELECT hstore(array_agg('_place_' || key), array_agg(value)) INTO extra_names
+        FROM each(location.name - result.name);
+      {% if debug %}RAISE WARNING 'Extra names: %', extra_names;{% endif %}
+
+      result.name := location.name || result.name || extra_names;
+      {% if debug %}RAISE WARNING 'Final names: %', result.name;{% endif %}
     END IF;
   END IF;
 

test/bdd/db/query/linking.feature

@@ -20,3 +20,23 @@ Feature: Searching linked places
         Then results contain
          | osm |
          | R13 |
+
+
+    Scenario: Differing names from linked places are searchable
+        Given the places
+         | osm  | class    | type           | admin | name  | geometry |
+         | R13  | boundary | administrative | 6     | Garbo | poly-area:0.1 |
+        Given the places
+         | osm  | class    | type           | admin | name  | geometry |
+         | N2   | place    | hamlet         | 15    | Vario | 0.006 0.00001 |
+        And the relations
+         | id | members       | tags+type |
+         | 13 | N2:label      | boundary |
+        When importing
+        Then placex contains
+         | object  | linked_place_id |
+         | N2      | R13 |
+        When sending search query "Vario"
+        Then results contain
+         | osm |
+         | R13 |

test/bdd/steps/steps_db_ops.py

@@ -93,6 +93,7 @@ def add_data_to_planet_ways(context):
 def import_and_index_data_from_place_table(context):
     """ Import data previously set up in the place table.
     """
+    context.nominatim.run_nominatim('refresh', '--functions')
     context.nominatim.run_nominatim('import', '--continue', 'load-data',
                                               '--index-noanalyse', '-q')