Fixed Move to grandparent/sibling

Moving a subtask to its grandparent, or making a task a sub-task of one
of its siblings, didn't work as expected. While the icons were being
updated correctly, the task didn't appear in the right location. That
was because, while the cached structure was being updated, the task
itself wasn't.

database/task-containers.sql

@@ -139,3 +139,32 @@ REVOKE EXECUTE
 CREATE TRIGGER tasks_item_au
 	AFTER UPDATE OF item_id ON tasks
 	FOR EACH ROW EXECUTE PROCEDURE tasks_item_au( );
+
+
+/*
+ * After an update on some task's logical container, set the task's parent ID.
+ */
+DROP FUNCTION IF EXISTS tasks_item_au( ) CASCADE;
+CREATE FUNCTION tasks_ltc_au( )
+		RETURNS TRIGGER
+		LANGUAGE PLPGSQL
+		SECURITY DEFINER
+	AS $tasks_ltc_au$
+BEGIN
+	UPDATE tasks
+		SET task_id_parent = (
+			SELECT task_id
+				FROM logical_task_containers
+				WHERE ltc_id = NEW.ltc_id )
+		WHERE task_id = NEW.task_id;
+	RETURN NEW;
+END;
+$tasks_ltc_au$;
+
+REVOKE EXECUTE
+	ON FUNCTION tasks_ltc_au( )
+	FROM PUBLIC;
+
+CREATE TRIGGER tasks_ltc_au
+	AFTER UPDATE OF ltc_id ON tasks
+	FOR EACH ROW EXECUTE PROCEDURE tasks_ltc_au( );

database/upgrade/from-bca6b99068cbf1dd4148d6bd5cb60e926162cfe1.sql

@@ -0,0 +1,37 @@
+--
+-- Upgrade the database from commit ID bca6b99068cbf1dd4148d6bd5cb60e926162cfe1
+--
+-- Run this from the top-level directory
+--
+
+
+\i database/config.sql
+\c :db_name
+
+BEGIN;
+
+	DROP FUNCTION IF EXISTS tasks_item_au( ) CASCADE;
+	CREATE FUNCTION tasks_ltc_au( )
+			RETURNS TRIGGER
+			LANGUAGE PLPGSQL
+			SECURITY DEFINER
+		AS $tasks_ltc_au$
+	BEGIN
+		UPDATE tasks
+			SET task_id_parent = (
+				SELECT task_id
+					FROM logical_task_containers
+					WHERE ltc_id = NEW.ltc_id )
+			WHERE task_id = NEW.task_id;
+		RETURN NEW;
+	END;
+	$tasks_ltc_au$;
+
+	REVOKE EXECUTE
+		ON FUNCTION tasks_ltc_au( )
+		FROM PUBLIC;
+
+	CREATE TRIGGER tasks_ltc_au
+		AFTER UPDATE OF ltc_id ON tasks
+		FOR EACH ROW EXECUTE PROCEDURE tasks_ltc_au( );
+COMMIT;