[fnielson1]

Summary

Stardrop currently deletes the archive it downloaded from Nexus Mods as soon as the mod is installed, and empties the Nexus download folder every time it starts. This keeps the original archives around for a while, so other tools can pick them up:

• After installing a single mod (the per-mod update button, "install all updates", and "Mod Manager Download" links), the archive stays until 7 days have passed.
  Collection installs are still deleted immediately as ModSyncCheck has no use for them.
• On startup, Stardrop now only deletes archives in the Nexus folder that are more than a week old.
• Since an archive can now still be there when the same file is downloaded again, the download opens the file with FileMode.Create instead of FileMode.CreateNew, so it overwrites the old copy. The overwrite only happens once the response has succeeded, so a download that never starts leaves the old archive alone.

Motivation

I maintain Mod Sync Check, which lets a multiplayer host send missing mods to joining players. When the host has a mod's original Nexus archive, it sends that file unchanged, and the player checks its MD5 with Nexus Mods before installing it. Players using Stardrop never had those archives, because Stardrop deleted them. With this change, Mod Sync Check moves them out of %AppData%\Stardrop\Data\Nexus when the game starts, whether or not the game was launched from Stardrop. Without such a tool, they're cleaned up after a week.

Testing

• Downloaded a mod with "Mod Manager Download": it installed normally, the archive stayed in the Nexus folder. Starting the game, Mod Sync Check moved it out and performed its actions correctly.
• Apparent behavior is unchanged to the user.