JOSM does not always respect the viewport in a session file

[Adrian]

What steps will reproduce the problem?

1. Launch JOSM or delete all layers if JOSM is already running.
2. Load the attached session file. Note that you see nine camera icons spread across the view (if the window has enough pixels, I'm using 1440 × 900 on a 96dpi display).
3. Delete all layers. (There was only one layer in the session file.)
4. Load session file session_23728.jos. It has the same viewport as the previous file. Note that you see nine groups of camera icons spread across the view. Nine of the photos are the same ones as in the previous session file.
5. Load the attached session file.

What is the expected result?

The view does not change because both session files have the same viewport.

What happens instead?

JOSM does a zoom-to-layer. Note a camera icon at top left, about 2km away. JOSM also does not store, in the view history, the viewport of the session file which has just been opened, so you cannot go back to it. In this example, this is not obvious, unless you change the view (drag or zoom) between steps 4 and 5. So JOSM does a zoom-to-layer instead of a zoom-to-viewport, if one or more other layers are already in existence. I think, if there are several layers in the session file, JOSM zooms to one of the layers rather than to the entire session.

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

Follow-up to ticket:23728#comment:27 and ticket:23728#comment:28. This behaviour has puzzled and annoyed me for a long time. At last I have worked out what is happening. I think it was different before the recent changes, but JOSM still often didn't respect the viewport.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2024-07-02 17:10:50 +0200 (Tue, 02 Jul 2024)
Revision:19128
Build-Date:2024-07-03 01:31:15
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (19128 en_GB) Mac OS X 12.7.5
OS Build number: macOS 12.7.5 (21H1222)
Memory Usage: 336 MB / 4096 MB (163 MB allocated, but free)
Java version: 21.0.3+9-LTS, Azul Systems, Inc., OpenJDK 64-Bit Server VM
Look and Feel: com.apple.laf.AquaLookAndFeel
Screen: Display 725375437 1920x1200x32bpp@59Hz (scaling 1.00×1.00)
Maximum Screen Size: 1920×1200
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: en_GB.UTF-8
System property file.encoding: UTF-8
System property sun.jnu.encoding: UTF-8
Locale info: en_GB
Numbers with default locale: 1234567890 -> 1234567890

Plugins:
+ ImportImagePlugin (36184)
+ InfoMode (36126)
+ PicLayer (1.0.3)
+ apache-commons (36273)
+ cadastre-fr (36226)
+ editgpx (36126)
+ ejml (36176)
+ geotools (36273)
+ http2 (36256)
+ imagery_offset_db (36289)
+ jackson (36273)
+ javafx (36200)
+ jaxb (36118)
+ jts (36004)
+ log4j (36273)
+ measurement (36256)
+ opendata (36256)
+ photo_geotagging (36276)
+ poly (36126)
+ reverter (36256)
+ turnrestrictions (36226)
+ undelete (36226)
+ utilsplugin2 (36241)
+ waydownloader (36196)

Last errors/warnings:
- 00025.723 E: unable to find dependency jaxb for plugin geotools
- 00025.724 E: unable to find dependency jaxb for plugin opendata
- 00174.973 E: java.io.FileNotFoundException: /Volumes/Untitled/20190909/IMG_20190909_161914.JPG (No such file or directory)
- 00397.592 E: java.io.FileNotFoundException: /Volumes/Untitled/20190914/IMG_20190914_172915.JPG (No such file or directory)
- 00458.568 E: java.io.FileNotFoundException: /Volumes/Untitled/20190909/IMG_20190909_161914.JPG (No such file or directory)
- 00564.094 E: java.io.FileNotFoundException: /Volumes/Untitled/20190914/IMG_20190914_172915.JPG (No such file or directory)
- 00576.406 E: java.io.FileNotFoundException: /Volumes/Untitled/20190914/IMG_20190914_172915.JPG (No such file or directory)
- 00605.907 E: java.io.FileNotFoundException: /Volumes/Untitled/20190909/IMG_20190909_161914.JPG (No such file or directory)

[Adrian]

session file