Fix SQL update logic (patch from 3.6.2)

layers/place/update_continent_point.sql

@@ -0,0 +1,48 @@
+DROP TRIGGER IF EXISTS trigger_flag ON osm_continent_point;
+DROP TRIGGER IF EXISTS trigger_refresh ON place_continent_point.updates;
+
+-- etldoc:  osm_continent_point ->  osm_continent_point
+CREATE OR REPLACE FUNCTION update_osm_continent_point() RETURNS VOID AS $$
+BEGIN
+  UPDATE osm_continent_point
+  SET tags = slice_language_tags(tags) || get_basic_names(tags, geometry)
+  WHERE COALESCE(tags->'name:latin', tags->'name:nonlatin', tags->'name_int') IS NULL;
+
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT update_osm_continent_point();
+
+-- Handle updates
+
+CREATE SCHEMA IF NOT EXISTS place_continent_point;
+
+CREATE TABLE IF NOT EXISTS place_continent_point.updates(id serial primary key, t text, unique (t));
+CREATE OR REPLACE FUNCTION place_continent_point.flag() RETURNS trigger AS $$
+BEGIN
+    INSERT INTO place_continent_point.updates(t) VALUES ('y')  ON CONFLICT(t) DO NOTHING;
+    RETURN null;
+END;
+$$ language plpgsql;
+
+CREATE OR REPLACE FUNCTION place_continent_point.refresh() RETURNS trigger AS
+  $BODY$
+  BEGIN
+    RAISE LOG 'Refresh place_continent_point';
+    PERFORM update_osm_continent_point();
+    DELETE FROM place_continent_point.updates;
+    RETURN null;
+  END;
+  $BODY$
+language plpgsql;
+
+CREATE TRIGGER trigger_flag
+    AFTER INSERT OR UPDATE OR DELETE ON osm_continent_point
+    FOR EACH STATEMENT
+    EXECUTE PROCEDURE place_continent_point.flag();
+
+CREATE CONSTRAINT TRIGGER trigger_refresh
+    AFTER INSERT ON place_continent_point.updates
+    INITIALLY DEFERRED
+    FOR EACH ROW
+    EXECUTE PROCEDURE place_continent_point.refresh();