JOSM deleted random files from disk after start (data loss)

[bilbo]

In revision: 2645
JOSM just deleted bunch of my files from disk without asking me.

I noticed this on console

Delete old plugin file dl.bat
Delete old plugin file dl
Delete old plugin file 0-site-http_josm.openstreetmap.de_plugin.txt
Delete old plugin file czechaddress-adresy.zip
Delete old plugin utilsplugin.jar

and the files were really lost.

This behavior is unacceptable, JOSM should NEVER just delete some random files that happen to be in plugin directory. One of the files was really an old plugin, one was something autogenerated by JOSM, but the czechaddress-adresy.zip is important file stored there and used by one of plugins and it takes quite long to re-download.
File "dl" and "dl.bat" were text files containing my notes - these are now lost. Well, I have backups, but it is extremely bad idea to just delete unknown files in plugin directory without asking.

[stoecker]

First: There should be no other files in plugins directory. Whatever plugin expects them to be there should be fixed. Plugin files reside in subdirectories. Other files in this directory will confuse the plugin loader. That may work now, but can fail everyday in the future.

The problem here is as always that JOSM has produced lots of outdated files over its lifetime so that deleting specific files will not catch everything. Also this directory is programmatically created and maintained, so user interaction in it is not expected or encouraged.

Maybe we can add a warning for filenames we think may not be autocreated.

[Gubaer]

(In [2817]) fixed #3063: Downloading a plugin yields 3 dialogs at the same time: Downloading plugin / You should restart JOSM / Plugin downloaded
fixed #3628: JOSM blocking itself updating broken plugin
fixed #4187: JOSM deleted random files from disk after start (data loss)
fixed #4199: new version - plugins update vs josm start [should be fixed. Be careful if you have two JOSM instances running. Auto-update of plugins in the second instance will fail because plugin files are locked by the first instance]
fixed #4034: JOSM should auto-download plugin list when it hasn't been downloaded before [JOSM now displays a hint]

fixed: splash screen showing again even if plugins are auto-updated
new: progress indication integrated in splash screen
new: cancelable, asynchronous download of plugins from preferences
new: cancelable, asynchronous download of plugin list from plugin download sites
new: asynchronous loading of plugin information, launch of preferences dialog accelerated
refactored: clean up, documentation of plugin management code (PluginHandler)