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This is a hard question to formulate to me, sorry for the long title... ):

I'm planning to map a town near me becouse has no buildings mapped, only road, so I downloaded a *.osm that cover the area to map, divided (for me) the area in small chunks and start editing, but today I came up with a doubt.

If someone changes something of the area that I downloaded, that I'm not going to edit, while I have the old local .osm that I'm editing (which hasen't the edit that the other user has changed), his change will be reverted, becouse of my .osm don't having the change?

I want to have this clear before uploading any "big" *.osm, to no revert any change other user would do. I don't know how to look for this in the Wiki, forum or anything. If this information is somewhere, please, tell me where.

Thanks!

asked 03 May '17, 13:43

MrAldisa's gravatar image

MrAldisa
66227
accept rate: 0%

Just checking - I presume that you're using JOSM for your offline editing?

(03 May '17, 13:50) SomeoneElse ♦

To directly answer the question

If someone changes something of the area that I downloaded, that I'm not going to edit, while I have the old local .osm that I'm editing (which hasen't the edit that the other user has changed), his change will be reverted, becouse of my .osm don't having the change?

No, his change will not be reverted. If however, your edits touches some of the same objects, which he edited, you will encounter conflicts, which you will have to resolve before you can succesfully upload your changes.

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answered 03 May '17, 18:46

Hjart's gravatar image

Hjart
3.0k42656
accept rate: 18%

If you try to upload a .osm file and others have made edits in that same area, that will create disagreement about which version is correct. In the JOSM editor, that disagreement is called a "conflict" and you will need to resolve it in favor of either your version or the other mapper's version before you will be allowed to upload your data.

JOSM will pop up a conflict editor window where the nodes in question are resolved one by one. This is a tedious process and in my experience best avoided if at all possible. If you must work offline, use small areas and upload your edits as often as you can to prevent these conflicts from occurring.

Cheers,

Dave

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answered 03 May '17, 13:56

AlaskaDave's gravatar image

AlaskaDave
5.4k76107164
accept rate: 16%

2

Are you sure about this? I think JOSM stores in the OSM file whether an object was changed or not, and only the changed and new objects are uploaded.

I tried to edit an OSM file directly some time ago, and then use JOSM to upload it, but because I didn't change the 'edited' qualifiers, JOSM refused to upload 'no changes'.

Of course, if the asker edited the same object as another used had edited in the meantime, you would indeed get an error, but for other objects, I suppose it will not bother with the existing data.

(03 May '17, 14:02) ff5722

But if the edit is in something that I haven't edit, I do'nt have to compare it isn't it? An JOSM at least will zoom in to the thing that has change.

I'm editing quite a big area, mapping a lot of buildings, it's more confortable to me to have a big *.osm that I can look a lot of times and correct in time that correcting after or don't knowing which chunk have you revised or which hasen't, instead of downloading again this chunk with an error, and upload it again (?)

It's my first "quite big" editing, i'm a bit newbie.

(03 May '17, 14:04) MrAldisa
1

you can always press CTRL+U to update and check for changes since you started editing.

(03 May '17, 14:19) ff5722
2

To clarify what I said above. Only nodes that have been changed by another mapper since your last update or upload will generate conflicts. Nodes that neither of you have touched will not cause a conflict no matter now big an area you are working on.

(03 May '17, 14:24) AlaskaDave
3

But if the edit is in something that I haven't edit, I don't have to compare it isn't it?

You'll have to check for duplicates - in case someone has added a building in the last couple of days and you later upload the same building.

(03 May '17, 14:25) SomeoneElse ♦
1

Correct, objects you haven't edited will not cause conflicts. When you are adding new objects you won't get a conflict either because there is no previous version to disagree with. However, as SomeoneElse points out, you should check each of your additions to make sure another mapper hasn't already added a building in that same place.

(03 May '17, 14:55) AlaskaDave

With Ctrl + U like ff5722 says, or like AlaskaDave says(by conflicts in JOSM)? (Or only changes made for me are uploaded?) This is getting a bit confusing for me...

(03 May '17, 15:16) MrAldisa
3

Ctrl+U is the keyboard shortcut for File>Update. Choosing Update by either method tells JOSM to update only those objects that have not been modified by you during the current session. If a different user has made edits in your area, they will appear in JOSM and can be edited further by you if you wish.

(03 May '17, 16:24) AlaskaDave
1

If you downloaded a large area, you even will have to deal with the mistakes that cause troubles on the edges of the area made by other mappers, one by one.

(03 May '17, 17:41) Hendrikklaas
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question asked: 03 May '17, 13:43

question was seen: 2,760 times

last updated: 03 May '17, 18:46

NOTICE: help.openstreetmap.org is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum