MapRoulette OSC doesn't always change the OSM layer

[taylor.smock]

API calls that MR makes (copied from JOSM console log, http://localhost:8111 added):

​http://localhost:8111/load_and_zoom?left=175.1235616207123&right=175.13642549514773&top=-37.26303869648842&bottom=-37.27009132988014&new_layer=false&layer_name=MR%20Task%2098697933%20Changes&changeset_comment=%23maproulette%3A%20New%20Zealand%20-%20WaterWayCheck&changeset_source=&select=w439812515

​http://localhost:8111/import?new_layer=false&layer_name=MR%20Task%2098697933%20Changes&layer_locked=false&download_policy=&upload_policy=&url=https://maproulette.org/api/v2/task/98697933/cooperative/change/task_98697933_change.osc

Original MR task: ​https://maproulette.org/challenge/18886/task/98697933

task_98697933_change.osc

<?xml version="1.0" encoding="UTF-8"?>
<osmChange generator="atlas ChangeDescription v0.0.1" version="0.6">
  <modify>
    <way id="439812515" version="1" visible="true">
      <tag k="LINZ:source_version" v="2012-06-06"/>
      <tag k="LINZ:layer" v="drain_cl"/>
      <tag k="waterway" v="drain"/>
      <tag k="attribution" v="http://wiki.osm.org/wiki/Attribution#LINZ"/>
      <tag k="source_ref" v="http://www.linz.govt.nz/topography/topo-maps/"/>
      <tag k="LINZ:dataset" v="mainland"/>
      <nd ref="3064243489"/>
      <nd ref="3064243448"/>
      <nd ref="3064243419"/>
      <nd ref="3064243388"/>
      <nd ref="4374879708"/>
      <nd ref="4374879645"/>
    </way>
  </modify>
</osmChange>

Note: This is both with edit in new JOSM layer (merging down to OSM data layer) and without editing in a new JOSM layer.

[skyper]

I read ?new_layer=false in both URLs. As this is the default setting it should not be set.

See also #19307 and #19308.

[taylor.smock]

Replying to skyper:

I read ?new_layer=false in both URLs. As this is the default setting it should not be set.

See also #19307 and #19308.

Maybe. Regardless, this is what MR sends.

There is another test MR task that works ( ​https://maproulette.org/challenge/18886/task/98698569 ), so it shouldn't be the ?new_layer=false parameter breaking things. But I was intending on debugging it later, once I had some spare time.

[Don-vip]

It doesn't seem to be a JOSM bug but a MapRoulette one? If I'm right can you please close this ticket as othersoftware?

[taylor.smock]

I haven't gotten around to debugging this yet.
It's kind of why I've assigned it to myself. :)
I think I checked the osc, and it looked good, but I don't recall it clearly.

[taylor.smock]

Replying to taylor.smock:

There is another test MR task that works ( ​https://maproulette.org/challenge/18886/task/98698569 ), so it shouldn't be the ?new_layer=false parameter breaking things. But I was intending on debugging it later, once I had some spare time.

It turns out it is a versioning issue in the OSC.

I'll attach a patch to at least give a debug message.