If loading terse .osm file with modifications, JOSM does not show changes in history but uploads them to OSM

[mnalis]

What steps will reproduce the problem?

1. load an .osm file having changes in format like this: <way id='1161677679' action='modify' visible='true' version='1'> instead of like this: <way id='1161677679' action='modify' timestamp='2023-04-12T12:25:27Z' uid='52552' user='Matija Nalis' visible='true' version='1' changeset='134814862'>
2. select such way in JOSM, and press ctrl-h for history
3. click upload

What is the expected result?

• in step (2), tags that were changed/added/deleted tags would be shown (as it normally happens with any changes!)

(additionally, even manually adding extra changes in JOSM to such elements afterwards will not show any changes in ctrl-h)

What happens instead?

• in step (2), JOSM shows like there are no changes in element whatsoever (i.e. that it is unmodified)
• however, in step(3), JOSM uploads those changes to OSM

Due to that inconsistency, user ends up confused (or even worse, oblivious) and likely ends up uploading data they though they verified, but they in fact didn't (as JOSM didn't tell them anything was modified, when in fact it was).

Please provide any additional information below. Attach a screenshot if possible.

I'm aware that those .osm files are externally produced and thus the "blame" should be on them. However, I think JOSM should handle loading such files better:

• either (preferably) accepting .osm files which missing user/uid and/or changeset attributes, and having history work correctly on them (i.e. if they are not strictly needed, which seems to be the case -- as I seem to be able to fake them with uid=1 changeset=1 and history works then),
• or throwing error when attempting to load such .osm files (if missing attributes are required for proper functioning of JOSM)

I'll try to work with this specific tool to fix the issue at their side (i.e. produce "full" list of attributes), but there might be others tools which exhibit the problem without people noticing, thus JOSM fix would be nice.

attached pictures: how ctrl-h History looks with "full" action=modify line (i.e. correctly shows modifications), vs. how it looks with short one (i.e. falsely shows there are no modifications)

The problem was noticed by using this tool which e.g. on ​https://dina.osm-hr.org/ar/opstine/jasenovac/Trebe%C5%BE.html (when clicking on the button on the bottom and then the link, links to this ​remote control URL

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2026-03-28 20:28:41 +0100 (Sat, 28 Mar 2026)
Revision:19555
Build-Date:2026-03-29 01:30:57
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (19555 en) Linux Debian GNU/Linux 13 (trixie)
Memory Usage: 1941 MB / 2987 MB (182 MB allocated, but free)
Java version: 21.0.11+10-1-deb13u2-Debian, Debian, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 1920x1080x[Multi depth]@60Hz (scaling 1.00×1.00)
Maximum Screen Size: 1920×1080
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: en_US.UTF-8
System property file.encoding: UTF-8
System property sun.jnu.encoding: UTF-8
Locale info: en_US
Numbers with default locale: 1234567890 -> 1234567890
Desktop environment: ICEWM
Java package: openjdk-21-jre:amd64-21.0.11+10-1~deb13u2
libcommons-logging-java: libcommons-logging-java:all-1.3.0-2
fonts-noto: fonts-noto:all-20201225-2
VM arguments: [-Dsun.java2d.opengl=true, --add-exports=java.base/sun.security.action=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.plugins.jpeg=ALL-UNNAMED, --add-exports=java.desktop/com.sun.imageio.spi=ALL-UNNAMED]
Dataset consistency test: No problems found

Plugins:
+ DirectUpload (36474)
+ FixAddresses (36474)
+ ImageWayPoint (36474)
+ Mapillary (1819)
+ PicLayer (273)
+ Review.Changes (1.1.1)
+ apache-commons (36474)
+ apache-http (36474)
+ buildings_tools (36474)
+ conflation (279)
+ ejml (36474)
+ geotools (36474)
+ imagery_offset_db (36474)
+ jackson (36474)
+ jaxb (36474)
+ jna (36474)
+ jts (36474)
+ libphonenumber (9.0.31)
+ log4j (36474)
+ mbtiles (v2.8.1)
+ opendata (36474)
+ openqa (116)
+ osmwiki-dataitem (0.0.8)
+ panoramax (8)
+ phonenumber (1.2.0)
+ pmtiles (36474)
+ pt_assistant (682)
+ reverter (36474)
+ todo (159)
+ turnrestrictions (36474)
+ undelete (36474)
+ urbaneye3d (2.2.2)
+ utilsplugin2 (36497)
+ wikipedia (448)

Tagging presets:
+ https://raw.githubusercontent.com/OpenNauticalChart/josm/master/INT-1-preset.xml
+ https://josm.openstreetmap.de/josmfile?page=Presets/Healthcare&zip=1
+ https://<user.name>.com/prezentacije/OpenStreetMap/josm-preset.xml
+ https://josm.openstreetmap.de/josmfile?page=Presets/Xmas&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/GuidepostDirectionsAndDestinations&zip=1

Map paint styles:
- https://josm.openstreetmap.de/josmfile?page=Styles/PublicTransport&zip=1
+ http://bezdomni.net/Styles_HighlightedCapesBays-style.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Styles/ColorWays&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Modified&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/CyclewaysStylingBNA&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/SidewalksPlus&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/BuildingColors&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/FixmeAndNote&zip=1
+ ${HOME}/tmp/g/1/openaddresses-HR.mapcss

Validator rules:
+ https://josm.openstreetmap.de/josmfile?page=Rules/KeepRight&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/QAToolInspiredValidations&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/OSMLint&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/MissingWeekdays&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/SourceObjectTag&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/IndoorRules&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/Pictures&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/MissingOpeningHours&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/CheckDate&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/FacebookWebsite&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/DuplicateAttributes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/MissingMain&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/OldCovid&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/NotCheck&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/ThisOrThat&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/ChargeRules&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/InvalidWebsiteProtocol&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/AddrFullWarning&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/AddrRelationWarning&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/CountryCodeCheck&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Rules/Geology&zip=1
+ https://raw.githubusercontent.com/stefan-a-bauer/josm-validators/master/mtb.validator.mapcss
+ https://github.com/Jungle-Bus/transport_mapcss/raw/gh-pages/transport.validator.zip
+ https://github.com/open-energy-transition/validate-my-grid/raw/refs/heads/gh-pages/power.validator.zip
+ https://josm.openstreetmap.de/josmfile?page=Rules/PublicTransportGtfs&zip=1
+ https://raw.githubusercontent.com/OpenNauticalChart/josm/master/Seamark.validator.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Rules/UnresolvedFIXMEs&zip=1

Last errors/warnings:
- 05346.026 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05346.165 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05346.307 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05346.446 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05346.584 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05346.726 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05346.864 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05347.002 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05347.142 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png
- 05347.281 E: Could not get message for https://osmose.openstreetmap.fr/images/markers/marker-b-%s.png

[mnalis]

full list of change attributes in .osm file shows changes correctly in ctrl-h

[mnalis]

shortened list of change attributes in .osm file incorrectly does not show any changes in ctrl-h (but still uploads those changes)