Nested folder selection does not work correctly

[tcgj]

Initial checklist

• I understand this is a bug report and questions should be posted in the Community Forum
• I searched issues and couldn’t find anything (or linked relevant results below)

Link to runnable example

No response

Steps to reproduce

Create a directory structure in OneDrive similar to this:

Folder A
| Folder B
  | File A

1. In the uploader, tick the checkbox for Folder A.
2. Then go into Folder A and tick the checkbox for Folder B.
3. Click "Select"

Note:

• I am testing this on OneDrive. The issue with selection is the same for all providers, but OneDrive displays the issue of File A being duplicated.

Expected behavior

1. Only one file, File A, should be listed.
2. Technically, ticking the checkbox for Folder A should automatically tick the checkbox for all of its children (i.e. if parent is selected, all child files/folders should be selected, and vice versa), so we shouldn't need to manually tick the checkbox for Folder B anyway.
3. If only some child files/folders are selected, the parent checkbox should be indeterminate:

Actual behavior

1. File A is listed twice instead of once.
2. Selecting parent folder is independent of selecting children. Selecting Folder A does not check Folder B, and allows you to select it separately.
3. Deselecting Folder A doesn't deselect Folder B, so we can never tell which parent folders may contain selected files.

[lakesare]

I can reproduce this issue, and I think your suggestions are sound - will take a look into it.

[Murderlon]

Fixed in #5050