"Download along" should automatically download smaller areas in places with many objects

[naoliv]

Trying to download along the way in the attached example, using 500 meters and 20 km² as values, we easily reach the maximum number of objects in a request:

2019-09-14 15:06:43.482 GRAVE: org.openstreetmap.josm.io.OsmApiException: ResponseCode=400, Error Header=<You requested too many nodes (limit is 50000). Either request a smaller area, or use planet.osm>
org.openstreetmap.josm.io.OsmApiException: ResponseCode=400, Error Header=<You requested too many nodes (limit is 50000). Either request a smaller area, or use planet.osm>
	at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:213)
	at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:137)
	at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:121)
	at org.openstreetmap.josm.io.OsmServerReader.getInputStream(OsmServerReader.java:85)
	at org.openstreetmap.josm.io.OsmServerReader.getInputStream(OsmServerReader.java:68)
	at org.openstreetmap.josm.io.BoundingBoxDownloader.parseOsm(BoundingBoxDownloader.java:194)
	at org.openstreetmap.josm.actions.downloadtasks.DownloadOsmTask$DownloadTask.parseDataSet(DownloadOsmTask.java:432)
	at org.openstreetmap.josm.actions.downloadtasks.DownloadOsmTask$DownloadTask.realRun(DownloadOsmTask.java:440)
	at org.openstreetmap.josm.gui.PleaseWaitRunnable.doRealRun(PleaseWaitRunnable.java:94)
	at org.openstreetmap.josm.gui.PleaseWaitRunnable.run(PleaseWaitRunnable.java:142)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:830)

Couldn't download along automatically fallback to a smaller area per request when this kind of problem happens?

JOSM:

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-09-12 23:23:47 +0200 (Thu, 12 Sep 2019)
Revision:15348
Build-Date:2019-09-12 21:28:35
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (15348 pt_BR) Linux Debian GNU/Linux bullseye/sid
Memory Usage: 292 MB / 2048 MB (108 MB allocated, but free)
Java version: 13+33-Debian-1, Debian, OpenJDK 64-Bit Server VM
Screen: :0.0 1920x1080
Maximum Screen Size: 1920x1080
Java ATK Wrapper package: libatk-wrapper-java:all-0.36.0-1
libcommons-compress-java: libcommons-compress-java:all-1.18-2
libcommons-logging-java: libcommons-logging-java:all-1.2-2
VM arguments: [-Dawt.useSystemAAFontSettings=gasp]

Plugins:
+ EasyPresets (1537621333)
+ FastDraw (34977)
+ OpeningHoursEditor (34977)
+ SimplifyArea (34977)
+ apache-commons (34908)
+ buildings_tools (34982)
+ ejml (35049)
+ geojson (124)
+ geotools (34908)
+ http2 (35062)
+ jaxb (35014)
+ jogl (1.2.3)
+ jts (35064)
+ log4j (34908)
+ measurement (35051)
+ opendata (35102)
+ reverter (35084)
+ tageditor (34977)
+ tagging-preset-tester (34908)
+ todo (30306)
+ turnlanes-tagging (281)
+ turnrestrictions (34977)
+ undelete (34977)
+ utilsplugin2 (35098)
+ wikipedia (v1.1.1)

[Don-vip]

If we do this we must still put a limit. Otherwise if someone draws a way that spans across the whole world, the huge number of recursive download tasks will lead to an uncomfortable situation :)