JOSM uploads a corrupt relation to the server

[avarab@…]

When playing around with the new relation editor & uploading JOSM produced this invalid request:

<osmChange version="0.6" generator="JOSM">
<create version="0.6" generator="JOSM">
  <node id='-1' visible='true' changeset='20' lat='-0.0088298733756484' lon='-0.11967994981759124' />
  <node id='-2' visible='true' changeset='20' lat='-0.1029889789908192' lon='0.029934913429599117' />
  <way id='-3' action='modify' visible='true' changeset='20'>
    <nd ref='-1' />
    <nd ref='-2' />
    <tag k='highway' v='motorway' />
  </way>
  <relation id='-4' visible='true' changeset='20'>
    <member type='way' ref='-3' role='' />
    <tag k='name' v='Another motorway' />
    <tag k='type' v='route' />
  </relation>
</create>
<modify version="0.6" generator="JOSM">
  <relation id='2' action='modify' visible='true' version='1' changeset='20'>
    <member type='way' ref='10' role='' />
    <tag k='ref' v='1234' />
    <tag k='name' v='A motorway route' />
    <tag k='type' v='route' />
  </relation>
  <relation id='3' action='modify' visible='true' version='1' changeset='20'>
    <member type='relation' ref='2' role='' />
    <member type='relation' ref='-5' role='' />
    <tag k='name' v='All motorways' />
    <tag k='type' v='route' />
  </relation>
</modify>
</osmChange>

To which the server replied:

Error: Placeholder Relation not found for reference -5 in relation 3.

.osm file attached.

[avarab@…]

A .osm file produced by JOSM with a corrupt relation

[stoecker]

Closed as duplicate of #2901.