Bug: Keep Local Backups causes Dump All Saves to fail

[nyanpasu64]

Describe the bug:

If I enable WebDAV backup, auto-upload all backups, and keep local backups, I can backup single saves, but "Dump All Saves" prints "Error creating backup!"

Steps needed to reproduce:

• Add a file /config/JKSV/webdav.json. Mine has contents:

{
    "origin": "http://192.168.0.90:6767",
    "basepath": "/",
}

• In the Gear tab, check both "Auto-upload backups to remote storage" and "Keep Local Backups".
• Restart JKSV. (If you perform one successful Dump All Saves then check Keep Local Backups, subsequent Dump All Saves will succeed until you restart the app and try again.)
• Press Y and hold A to dump all saves.

Expected behavior:

Saves are backed up.

What happens instead:

The progress popup appears and immediately disappears, followed by an Android-toast-style message saying "Error creating backup!"

This bug seems closely related to #323 which was fixed earlier. That was another issue producing message "error creating backup!", which turned out to be introduced by "Keep Local Backups". It's claimed to be fixed in 12/02/2025, but I got a similar error a different way.

Log file output:

Check sdmc:/config/JKSV/JKSV.log for any meaningful output that may be useful in diagnosing the bug in question. The last lines should be the most valuable.

[Thu May 28 08:50:42 2026] BaseState.cpp::BaseState::BaseState(bool)::12::17:1159
[Thu May 28 08:50:42 2026] DataContext.cpp::data::DataContext::import_svi_files(sys::Task*)::172::21::fslib::Directory.cpp::fslib::Directory::open(const fslib::Path&, bool)::62:202
[Thu May 28 08:50:42 2026] BaseState.cpp::BaseState::~BaseState()::18::17:1159
[Thu May 28 08:50:53 2026] DataContext.cpp::data::DataContext::import_svi_files(sys::Task*)::172::21::fslib::Directory.cpp::fslib::Directory::open(const fslib::Path&, bool)::62:202
[Thu May 28 08:50:59 2026] MiniZip.cpp::fs::MiniZip::open(const fslib::Path&)::32::23::nullptr!
[Thu May 28 08:50:59 2026] MiniZip.cpp::fs::MiniZip::open(const fslib::Path&)::32::23::nullptr!
[Thu May 28 08:50:59 2026] MiniZip.cpp::fs::MiniZip::open(const fslib::Path&)::32::23::nullptr!
[Thu May 28 08:50:59 2026] MiniZip.cpp::fs::MiniZip::open(const fslib::Path&)::32::23::nullptr!
[Thu May 28 08:50:59 2026] MiniZip.cpp::fs::MiniZip::open(const fslib::Path&)::32::23::nullptr!

[nyanpasu64]

I've added a patch in https://github.com/nyanpasu64/JKSV, though the code has a lot of technical debt around Dump All Saves where I want to unify path calculation between regular backups and Dump All Saves as well as local and WebDAV modes (where "Keep Local Backups" requires calculating paths anyway, and it would be better in a single function).