JOSM blowing up streets (highways) ids on reeopen

I’m being hit by a strange renaming of streets created using JOSM. Here’s the scenario:

  1. Download a map of a city, only highways that are primary/tertiary/secondary/residential
  2. Add/remove/adjust(for example, merge or split) some of the roads in JOSM.
  3. Do not upload the changes to OSM. I need the changes for my personal use.
  4. Save the file and close JOSM. Shut down the machine. Wake up another day, start JOSM.
  5. (optional) Make a change in the map (for example, add a road).
  6. Save the file.

Effect: all the streets that were added with JOSM have different numbers than day before (in my case, all of them are mode of exactly 4 digits and possibly a # with a number in the back, a minus or two in the front).
Expected: all streets that remained unchanged should have the same numbers (ids) as day ago.

This is a serious issue for me, as I’m relying on the road ids in other software.

Is there any way to keep JOSM from changing the road numbers? Any help will be appreciated!

Thanks a lot,

I can confirm that negative ids (that is, temporary ids that were not issued by the OSM server and are not globally valid) are changed when opening and re-saving a file in JOSM. I don’t understand why this is being done, though.

If you are sure that you will never want to upload your edits and never want to update it with new content from the OSM server, you could replace the negative IDs by positive IDs (that are not used elsewhere in the file) through a script.

To contact the developers, you could also send to send a mail to josm-dev or add a bug report to JOSM trac.