How does merging of downloaded data work?

[anonymous]

Hi, I think this is more of a call for help rather than a bug report but I didn't know where
else to post the question.

If I have some current OSM data which I then edit (move stuff around, delete nodes, etc.) and then I ask for a download of the same area, josm downloads the data but then doesn't update the display or even complain about conflicts, it's as if it just threw the downloaded data away. What's happening? Why isn't it replacing the stuff I deleted and griping about the
nodes I have moved?

Thanks

[stoecker]

Do not download dat into separate layers. The separate layers are not one of the best ideas of josm and probably will vanish some day anyway.

[anonymous]

Replying to stoecker:

Do not download dat into separate layers. The separate layers are not one of the best ideas of josm and probably will vanish some day anyway.

I wasn't using separate layers, I was downloading into the same layer.

[stoecker]

Then please your problem a bit better. When you redownload data conflicts are only shown if there are conflicts. Otherwise you wont see much difference except other users changed stuff in the same time.

[xeen]

JOSM basically compares re-downloaded data against what you got when downloading it for the first time. So, if you edit the data, JOSM marks this as "needs to be updated" but doesn't actually commit the changes. Therefore, when you download the data again, nothing happens. As Stöcker pointed out, you'll get a warning if other users changed data in the meantime.