Download parent ways/relations downloads way nodes twice

[GerdP]

What steps will reproduce the problem?

1. Create new edit layer
2. Download node 1707790074 without refereres
3. Select the node and press Ctrl+Alt+D to "download parent ways/relations"

What is the expected result?

The following log messages about downloads:

2020-01-26 11:34:36.560 INFO: GET https://api.openstreetmap.org/api/0.6/node/1707790074/ways -> HTTP_1 200 (565 B)
2020-01-26 11:34:36.563 INFO: Way 35359130 with 4 nodes is incomplete because at least one node was missing in the loaded data.
2020-01-26 11:34:36.564 INFO: Way 39276020 with 3 nodes is incomplete because at least one node was missing in the loaded data.
2020-01-26 11:34:36.565 INFO: Way 158615405 with 8 nodes is incomplete because at least one node was missing in the loaded data.
2020-01-26 11:34:36.652 INFO: GET https://api.openstreetmap.org/api/0.6/node/1707790074/relations -> HTTP_1 200 (189 B)
2020-01-26 11:34:36.722 INFO: GET https://api.openstreetmap.org/api/0.6/way/35359130/full -> HTTP_1 200
2020-01-26 11:34:36.792 INFO: GET https://api.openstreetmap.org/api/0.6/way/39276020/full -> HTTP_1 200
2020-01-26 11:34:36.857 INFO: GET https://api.openstreetmap.org/api/0.6/way/158615405/full -> HTTP_1 200

What happens instead?

One more useless download (ways were downloaded with the /full suffix, so there should be no incomplete nodes):

2020-01-26 11:34:36.929 INFO: GET https://api.openstreetmap.org/api/0.6/nodes?nodes=21563481,3972566713,21590698,21392272,21392273,21563489,4719617974,4822267109,4822267110,1707790096,1707790085,4822267107 -> HTTP_1 200

Please provide any additional information below. Attach a screenshot if possible.

I am working on a patch. Maybe also for #12303.

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-01-02 22:34:59 +0100 (Thu, 02 Jan 2020)
Build-Date:2020-01-02 21:52:31
Revision:15628
Relative:URL: ^/trunk

Identification: JOSM/1.5 (15628 en) Windows 10 64-Bit
OS Build number: Windows 10 Home 1903 (18362)
Memory Usage: 941 MB / 4551 MB (623 MB allocated, but free)
Java version: 1.8.0_221-b11, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-XX:StartFlightRecording=name=MyRecording2,settings=d:\dbg\gerd.jfc, -XX:FlightRecorderOptions=defaultrecording=true,dumponexit=true,dumponexitpath=e:\ld\perf_20200126_112549.jfr]
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (35250)
+ PolygonCutOut (v0.7)
+ apache-commons (35092)
+ buildings_tools (35248)
+ continuosDownload (91)
+ ejml (35122)
+ geotools (35169)
+ jaxb (35092)
+ jts (35122)
+ merge-overlap (35248)
+ o5m (35248)
+ opendata (35280)
+ pbf (35248)
+ poly (35248)
+ reverter (35248)
+ undelete (35248)
+ utilsplugin2 (35248)

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.

[GerdP]

download only incomplete nodes

[GerdP]

I don't yet understand why we have these two lines in

            // Don't retrieve any nodes we've already grabbed
            nodes.removeAll(targetLayer.data.getNodes());

The effect is that the freshly downloaded nodes are not used to update the existing ones. Was introduced in #5293 but probably isn't useful anymore.

[GerdP]

18624.2.patch simplifies the code and improves performance a lot when retrieving the parents for many nodes, e.g. all nodes of a way.
Does not yet use Overpass API.

[GerdP]

In 15787/josm:

see #18624: Download parent ways/relations downloads way nodes twice (or more)
Improve performance, esp. when multiple nodes of the same way are selected

• DownloadReferrersTask: download all incomplete nodes of all parent ways with one MultiFetchServerObjectReader instead of repeating this step for each parent way. Saves lots of FULL api calls for the parent ways (/full)
• updated parent way nodes are recognized
• DownloadPrimitivesWithReferrersTask creates only one DownloadReferrersTask for all primitives to profit from the above changes

[GerdP]

forgot to close this, problem is fixed, possible usage of overpass api see #12303