[josm-dev] Bug in Validator Plugin

[Jason Reid]

I had noted this on one of the other lists the other day, but finally 
had a chance to have a look at whats happening. The issue is with the 
remove duplicate nodes feature, combined with not-yet-uploaded nodes and 
I suspect is the cause of a lot of the 412 errors that people keep 
running into. This was tested with josm-latest.jar (as of 2pm MST 
today), and a copy of validator.jar downloaded at the same time.

I started by creating a simple way and duplicated its nodes as such:

<?xml version='1.0' encoding='UTF-8'?>
<osm version='0.5' generator='JOSM'>
  <bound box='25.0,25.0,25.001,25.001' 
origin='http://www.openstreetmap.org/api/0.5' />
  <node id='-1' action='modify' visible='true' lat='25.000517497207184' 
lon='25.00030124287105' />
  <node id='-2' action='modify' visible='true' lat='25.000391053864853' 
lon='25.000615946300847' />
  <node id='-3' action='modify' visible='true' lat='25.000587743508476' 
lon='25.00071429112266' />
  <node id='-4' action='modify' visible='true' lat='25.000643940549512' 
lon='25.000385538432603' />
  <node id='-5' action='modify' visible='true' lat='25.000517497207184' 
lon='25.00030124287105' />
  <node id='-6' action='modify' visible='true' lat='25.000391053864853' 
lon='25.000615946300847' />
  <node id='-7' action='modify' visible='true' lat='25.000587743508476' 
lon='25.00071429112266' />
  <node id='-8' action='modify' visible='true' lat='25.000643940549512' 
lon='25.000385538432603' />
  <way id='-1' action='modify' visible='true'>
    <nd ref='-1' />
    <nd ref='-2' />
    <nd ref='-3' />
    <nd ref='-4' />
    <nd ref='-1' />
  </way>
</osm>

I then ran validator, and selected the remove duplicate nodes. It 
results in:

<?xml version='1.0' encoding='UTF-8'?>
<osm version='0.5' generator='JOSM'>
  <bound box='25.0,25.0,25.001,25.001' 
origin='http://www.openstreetmap.org/api/0.5' />
  <node id='-1' action='modify' visible='true' lat='25.000517497207184' 
lon='25.00030124287105' />
  <node id='-2' action='modify' visible='true' lat='25.000391053864853' 
lon='25.000615946300847' />
  <node id='-3' action='modify' visible='true' lat='25.000587743508476' 
lon='25.00071429112266' />
  <node id='-4' action='modify' visible='true' lat='25.000643940549512' 
lon='25.000385538432603' />
  <way id='-5' action='modify' visible='true'>
    <nd ref='-6' />
    <nd ref='-2' />
    <nd ref='-7' />
    <nd ref='-8' />
    <nd ref='-6' />
  </way>
</osm>

Which as you can see updated the way, however with nodes that it then 
removed. If I use the remove unconnected nodes feature it results in the 
proper:

<?xml version='1.0' encoding='UTF-8'?>
<osm version='0.5' generator='JOSM'>
  <bound box='25.0,25.0,25.001,25.001' 
origin='http://www.openstreetmap.org/api/0.5' />
  <node id='-1' action='modify' visible='true' lat='25.000517497207184' 
lon='25.00030124287105' />
  <node id='-2' action='modify' visible='true' lat='25.000391053864853' 
lon='25.000615946300847' />
  <node id='-3' action='modify' visible='true' lat='25.000587743508476' 
lon='25.00071429112266' />
  <node id='-4' action='modify' visible='true' lat='25.000643940549512' 
lon='25.000385538432603' />
  <way id='-5' action='modify' visible='true'>
    <nd ref='-1' />
    <nd ref='-2' />
    <nd ref='-3' />
    <nd ref='-4' />
    <nd ref='-1' />
  </way>
</osm>

If the entire set of nodes and ways has been uploaded it does seem to 
work as it should, and modifies the way appropriately however if there 
is a non-uploaded node the way will get messed up similar to if all the 
nodes were not uploaded.

-Jason Reid