Hi all!

Today I noticed a big problem in OSM map of Moscow, Russia. Someone messed up a dozen of streets in the center of the city. Nothing was deleted, but nodes and ways were moved away from their positions. Some strange polygons were added near the mess.

All this was done by user alkmay. I wrote him - but no response.

I tries to undo the changes in potlatch, but it is still not shown in OSM - I still see the mess. What is the period when the undo process will show up in OSM?

Is there any way to prevent such things??? There is a team of people working a lot with Moscow map preparing it to be used in a routing application, so we are really concerned about such things…

The (Mapnik layer) map is rerendered every week or so, so your recovery work won’t show up until then.

There’s no way to prevent such changes - the server can hardly know whether a change is good or bad! But you can use something like itoworld’s OSM Mapper website to alert you of any changes in a given area.

You see, the thing is that the the recovery work wont save even in potlatch… so if you undo something, wait till it uploads, then log off and on again - the state of things is as wrong as it was before your “undo’s”.

Yeh, we are not talking about mapnik, we are talking about OSM data. The yesterday undo operation didn’t make any changes. I open the area in potlatch and I see that the mess is stil there.

Take a look yourself

I hit “H” and I see that the author of the change is not alkmay, but Eugene120. And it’s not true - Eugene is the author of the change I reverted to. And the same shit with all other changes I was undoing yesterday…

What can we do with this?

And about monitoring of the area - I commit hundreds of changes every day, and so do about 20 people from our team, it’s impossible to monitor all the changes. OSM developers should realy think about it - OSM becomes popular, so more stupid people will learn about it and more damage can be done. Just imagine if someone takes josm, selects the whole center of a city and drags it… It will take months to undo this operation if we use potlatch for it…

May be we should think of a tool to undo all the operations of a single user, or all the operations made during a ingle potlarch session or within one josm upload.

You can try to contact the user who caused this, most likely he/she isn’t aware of the problems he/she created. Regarding the revert action, that should work just fine in Potlatch. You can also try to contact Frederik Ramm, he has a script with which he can bulk reverse edits from a specific user. Itoworld has a osmmapper service with which you can monitor specific areas for changes.

Thanx for the advice. I’ll keep in mind the info about the bulk undo script. For the moment with help from Richard I managed to revert all the changes and correct all the problems.

Great, but don’t forget to contact the user who caused it, just to prevent it happening again (by this user).

unfortunately, he doesn’t answer.

That’s a pitty, well, let’s hope he did read your message and will be more careful in the future…