From 1d203fdb3c48592c3a72b91c29b7d92f64253c8c Mon Sep 17 00:00:00 2001
From: Sarah Hoffmann <lonvia@denofr.de>
Date: Mon, 23 May 2022 10:11:28 +0200
Subject: [PATCH] fix bug with keeping linking on updates

When moving the finding of linked places to the precomputation stage,
it was also moved before the statement where the linked_place_id was
removed from the linkee. The result was that the current linkee was
excluded when looking for a linked place on updates because it was
still linked to the boundary to be updated.

Fixed by allowing to either keep the linkage or change to an unlinked
place.
---
 lib-sql/functions/placex_triggers.sql    | 15 +++++++++------
 test/bdd/db/update/linked_places.feature | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/lib-sql/functions/placex_triggers.sql b/lib-sql/functions/placex_triggers.sql
index f8580d7f..92c0c4ec 100644
--- a/lib-sql/functions/placex_triggers.sql
+++ b/lib-sql/functions/placex_triggers.sql
@@ -278,7 +278,7 @@ BEGIN
              OR position(bnd_name in lower(name->'name')) > 0)
         AND placex.class = 'place' AND placex.type = bnd.extratags->'place'
         AND placex.osm_type = 'N'
-        AND placex.linked_place_id is null
+        AND (placex.linked_place_id is null or placex.linked_place_id = bnd.place_id)
         AND placex.rank_search < 26 -- needed to select the right index
         AND placex.type != 'postcode'
         AND ST_Covers(bnd.geometry, placex.geometry)
@@ -294,7 +294,7 @@ BEGIN
       WHERE placex.class = 'place' AND placex.osm_type = 'N'
         AND placex.extratags ? 'wikidata' -- needed to select right index
         AND placex.extratags->'wikidata' = bnd.extratags->'wikidata'
-        AND placex.linked_place_id is null
+        AND (placex.linked_place_id is null or placex.linked_place_id = bnd.place_id)
         AND placex.rank_search < 26
         AND _st_covers(bnd.geometry, placex.geometry)
       ORDER BY lower(name->'name') = bnd_name desc
@@ -318,7 +318,7 @@ BEGIN
              OR (bnd.rank_address = 0 and placex.rank_search = bnd.rank_search))
         AND placex.osm_type = 'N'
         AND placex.class = 'place'
-        AND placex.linked_place_id is null
+        AND (placex.linked_place_id is null or placex.linked_place_id = bnd.place_id)
         AND placex.rank_search < 26 -- needed to select the right index
         AND placex.type != 'postcode'
         AND ST_Covers(bnd.geometry, placex.geometry)
@@ -759,9 +759,6 @@ BEGIN
   DELETE FROM place_addressline WHERE place_id = NEW.place_id;
   result := deleteRoad(NEW.partition, NEW.place_id);
   result := deleteLocationArea(NEW.partition, NEW.place_id, NEW.rank_search);
-  UPDATE placex set linked_place_id = null, indexed_status = 2
-         where linked_place_id = NEW.place_id;
-  -- update not necessary for osmline, cause linked_place_id does not exist
 
   NEW.extratags := NEW.extratags - 'linked_place'::TEXT;
 
@@ -770,6 +767,12 @@ BEGIN
   linked_place := NEW.linked_place_id;
   NEW.linked_place_id := OLD.linked_place_id;
 
+  -- Remove linkage, if we have computed a different new linkee.
+  UPDATE placex SET linked_place_id = null, indexed_status = 2
+    WHERE linked_place_id = NEW.place_id
+          and (linked_place is null or linked_place_id != linked_place);
+  -- update not necessary for osmline, cause linked_place_id does not exist
+
   IF NEW.linked_place_id is not null THEN
     NEW.token_info := null;
     {% if debug %}RAISE WARNING 'place already linked to %', OLD.linked_place_id;{% endif %}
diff --git a/test/bdd/db/update/linked_places.feature b/test/bdd/db/update/linked_places.feature
index 99614b7f..3dedc468 100644
--- a/test/bdd/db/update/linked_places.feature
+++ b/test/bdd/db/update/linked_places.feature
@@ -2,6 +2,25 @@
 Feature: Updates of linked places
     Tests that linked places are correctly added and deleted.
 
+    Scenario: Linking is kept when boundary is updated
+        Given the places
+            | osm | class | type | name | geometry |
+            | N1  | place | city | foo  | 0 0 |
+        And the places
+            | osm | class    | type           | name | admin | geometry |
+            | R1  | boundary | administrative | foo  | 8     | poly-area:0.1 |
+        When importing
+        Then placex contains
+         | object | linked_place_id |
+         | N1     | R1 |
+        When updating places
+         | osm | class    | type           | name | name+name:de | admin | geometry |
+         | R1  | boundary | administrative | foo  | Dingens      | 8     | poly-area:0.1 |
+        Then placex contains
+         | object | linked_place_id |
+         | N1     | R1 |
+
+
     Scenario: Add linked place when linking relation is renamed
         Given the places
             | osm | class | type | name | geometry |
-- 
2.39.5