Opened 11 years ago

Closed 11 years ago

#639 closed defect (fixed)

Inconsistencies in OSM data

Reported by: martin.schaller@… Owned by: richard@…
Priority: major Milestone:
Component: potlatch (flash editor) Version:
Keywords: Cc:

Description

The osm database seems to contain some inconsistencies. For example, way 19854486 contains in the planet.osm nodes in the range 130273708 - 130288164. The history of the way also shows this nodes, but in the current version (with the same timestamp) they are not available. The nodes itself are reported as "410 Gone".

Change History (3)

comment:1 Changed 11 years ago by jburgess@…

Component: datasourcespotlatch (flash editor)
Owner: changed from mikel_maron@… to richard@…

The history data looks odd. The way was created referencing the 130273708 node at 01:43:59

<?xml version="1.0" encoding="UTF-8"?>
<osm version="0.5" generator="OpenStreetMap server">
  <way id="19854486" visible="true" timestamp="2008-01-07T01:43:59+00:00" user="AiNikolas">
    <nd ref="207713785"/>
    <nd ref="138470330"/>
    <nd ref="130273708"/>
...

but exactly 1 second earlier it seems that node was deleted...

...
  <node id="130273708" lat="40.7232322" lon="22.8403975" user="AiNikolas" visible="true" timestamp="2007-11-24T17:52:14+00:00"/>
  <node id="130273708" lat="40.7232322" lon="22.8403975" user="AiNikolas" visible="false" timestamp="2008-01-07T01:43:58+00:00"/>
</osm>

The way wsa created by Potlatch. Any Ideas Richard?

comment:2 Changed 11 years ago by richard@…

Priority: minormajor
Status: newassigned

Appears to be an issue with splitting ways. Am investigating.

Node 130273708 (problem node)
http://www.openstreetmap.org/api/0.5/node/130273708/history
originally in way 13874445 at 2007-11-24T17:43:55+00:00
deleted at 2008-01-07T01:43:58+00:00
(also, shouldn't be rewritten every time!)

Way 13874445 (deleted)
created at 2007-11-24T17:43:55+00:00
deleted at 2007-11-24T17:45:51+00:00

Way 18925657 (southern section)
rewritten at 2008-01-07T01:43:58+00:00 when node was removed from it and deleted

Way 19854484 (bridge)
first written at 2008-01-07T01:43:57+00:00 containing the node
rewritten at 2008-01-07T01:44:08+00:00 when node was removed

Way 19854486 (live, containing problem node)
created at 2008-01-07T01:43:59

So it appears that:

  • 01:43:57 - user splits way 18925657
  • 01:43:57 - bridge/northern section written as new way 19854484
  • 01:43:58 - southern section rewritten as way 18925657, all nodes only in northern section are deleted (those also in other ways are retained)
  • 01:43:59 - user splits way 19854484
  • 01:43:59 - northern section written as new way 19854486, with full list of nodes as if they hadn't been deleted
  • 01:44:08 - bridge rewritten as way 19854484

It seems possible that (despite the timestamps) the southern section uniquenodes table is being assembled before the northern section's way_nodes are written. Therefore the southern section uniquenodes table contains the nodes of the northern section.

comment:3 Changed 11 years ago by richard@…

Resolution: fixed
Status: assignedclosed

When splitting a way, 0.6c will now write both 'halves' immediately, rather than one immediately and one when the user deselects. This means they will be batched in the same HTTP request and the above problem of processing two in parallel will be avoided.

In addition, 0.6c also checks thoroughly that all nodes in a way are visible on 'putway'.

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