pyosmium-up-to-date give a strange message when no update to do

[jocelynj]

When launching pyosmium-up-to-date on a pbf, and no update is available from the server, the command reports an error on a state file, instead of reporting that no update is available.

$ wget http://download.geofabrik.de/europe/andorra-latest.osm.pbf
$ pyosmium-up-to-date -vvvvv andorra-latest.osm.pbf 
2020-12-10 22:04:11,336 DEBUG: Replication information found in OSM file header.
2020-12-10 22:04:11,336 DEBUG: Replication URL: http://download.geofabrik.de/europe/andorra-updates
2020-12-10 22:04:11,336 DEBUG: Replication sequence: 2817
2020-12-10 22:04:11,336 DEBUG: Replication timestamp: 2020-12-09T21:42:03Z
2020-12-10 22:04:11,338 INFO: Using replication service at http://download.geofabrik.de/europe/andorra-updates
2020-12-10 22:04:11,338 DEBUG: Using given sequence ID 2817
2020-12-10 22:04:11,406 DEBUG: Loading state info 2818 failed with: HTTP Error 404: Not Found
2020-12-10 22:04:11,408 ERROR: Cannot download state information for ID 2817. Is the URL correct?

I would expect to print the message "No new updates found." instead.

In addition, would it be possible to generate a different error code when no update is available? It would be useful to check if we should rerun the script or not, in case of a transient serveur connection issue.

[lonvia]

Fixed in 56c10da. pyosmium-up-to-date now returns an exit code 2 when the file already is up to date.

[joto]

Shouldn't it return 0 in this case? If the data is already up to date, that isn't an error, is it?

[lonvia]

Hmm, it did return an error before, just a different one. So the commit didn't change the behaviour here. But I see your point that returning 0 might be the better way to handle the situation in scripts. @jocelynj how about your use case?

[jocelynj]

I don't really care here, I only need to be able to differentiate between an up-to-date pbf, or an issue when updating the pbf file.

Returning 0 in the case of a pbf that is already on the latest version is fine for me, and would simplify my scripts that relaunch pyosmium-up-to-date several times when getting an error.

[lonvia]

Changed return code to 0.