Files recognized as archives inside mods are extracted and not properly added to the mod

[Al12rs]

Bug Report

Outline:

If a mod added to the library contains a file that the app recognizes as an archive, the app will attempt to extract the contents of that archive, and the file entry is recorded as 0 sized file. It's unclear where the nested files end up.

This breaks installation of any mod that contains a file in archive format that should not be extracted.

Details

This was noticed in #2193, where a Credits.xlsx file (archive format containing Excel sheet) was missing from the App installation of a SDV collection.
Investigation revealed that the file was being recognized as an archive, and a 0 sized ghost entry was present rather than the full archive as expected.

Steps to reproduce

• Install https://www.nexusmods.com/stardewvalley/mods/20414?tab=files
• Preview Apply changes, notice Credits.xlsx file with 0 size.
• Apply and Credits file should be missing

What is the expected behaviour?

Not sure yet.
The reason this happens in the first place is to support the installation of certain mods that come with nested archives that need to be extracted during installation. We want to have all the files available upfront, before installation.

Tentatively, my assumption would be that we would want to potentially index all the child files, but also index the parent archive.

This could have the very bad downside of the app backing up data twice, both the archive contents and the archive itself.
If we encounter an entire game where such archives are common (e.g. if this where to happen for something like BSA archives), that would be pretty disastrous space efficiency wise and have big negative impact on Download finalization time (overhead of extracting the inner data).

[erri120]

I think we can look into repacking if we need to deploy an archive as an archive.

[Al12rs]

I don't know if I would want to have something like a BSA extracted as loose files in our data store. Repacking on Apply seems quite a potential slowdown if you are dealing with a higher number of archives.

I think I would rather lean towards the opposite, of extracting during mod installation, for only those installers that require this.

[Al12rs]

See relevant comment:

• Discrepency when installing a collection in the app vs Vortex #2193 (comment)

I think the best way to fix this for now, and perhaps forever, is to have a specific list of archives we descend into. We should do this analysis for .zip, .rar, .7z, etc but not for .xslx files.

Sounds good, there are some games where mods are supposed to contain zip files, so we should store the archive in the filestore still, hopefully restricting the extraction by file extension limits the size overhead problem.