Error header: Placeholder IDs must be unique for created elements.

[osm@…]

POST ​http://www.openstreetmap.org/api/0.6/changeset/3402866/upload... Bad Request
Error header: Placeholder IDs must be unique for created elements.
org.openstreetmap.josm.io.OsmApiException: ResponseCode=400, Error Header=<Placeholder IDs must be unique for created elements.>

at org.openstreetmap.josm.io.OsmApi.sendRequest(OsmApi.java:562)
at org.openstreetmap.josm.io.OsmApi.sendRequest(OsmApi.java:462)
at org.openstreetmap.josm.io.OsmApi.uploadDiff(OsmApi.java:423)
at org.openstreetmap.josm.io.OsmServerWriter.uploadChangesAsDiffUpload(OsmServerWriter.java:116)
at org.openstreetmap.josm.io.OsmServerWriter.uploadOsm(OsmServerWriter.java:163)
at org.openstreetmap.josm.actions.UploadAction$UploadPrimitivesTask.realRun(UploadAction.java:588)
at org.openstreetmap.josm.gui.PleaseWaitRunnable.doRealRun(PleaseWaitRunnable.java:62)
at org.openstreetmap.josm.gui.PleaseWaitRunnable.run(PleaseWaitRunnable.java:116)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:636)

Ideally JOSM would ensure that the placeholder element IDs it tries to upload are unique.

(Manual methods for fixing the .osm also appreciated).

[anonymous]

Note that during the above editing session no plugins were used---whereas ticket #3812 was attributed to the "lakewalker" plugin.

[osm@…]

Okay, this was node id='-117'. This was included twice as a node, and twice (two consecutive) as new points in an existing way (#41426580).

[mjulius]

The question is how did the duplicate node in there? I suppose this file has been written by JOSM?

Anyway, opening the file in latest JOSM and saving it again removes the duplicate node. It is still present twice in that way. Validator will find that one.

So, unless you can reproduce the issue with latest JOSM this ticket probably should be closed as worksforme.

[osm@…]

I don't know how reproducible this is going to be "on demand". The dataset was initialised by downloading from OSM a sequence of areas following a GPS track (JOSM has a function to do this). Map editing was then done in JOSM, and after an hour or two, an upload was attempted (which failed with the above error message). To avoid losing the mapping work, I saved the layer to file---this file that JOSM saved is what is attached here.

At some point during the editing, JOSM will have introduced the duplicated node. Note that the node has a negative (temporary) ID, and therefore can only have been created by JOSM itself.

You mentioned that a validator should catch this. Is the validator run on the (unsaved) dataset before uploading or only at file import stage?

[osm@…]

The way in question, in the OSM database, shows no duplicated points before:

​http://www.openstreetmap.org/browse/way/41426580/history

which should confirm that the duplication can only have been inserted by JOSM during editing.

[simon04]

Replying to mjulius:

So, unless you can reproduce the issue with latest JOSM this ticket probably should be closed as worksforme.

Please re-open the ticket when this behaviour is reproduceable.