Saving inside currently open sketch generates 257 nested folders

[per1234]

Describe the bug
When you save a sketch inside the folder of the currently open sketch, 257 nested folders are created inside that folder.

After this, the Pro IDE no longer works.

To Reproduce
Steps to reproduce the behavior:

1. File > Save As...
2. Save the sketch.
3. File > Save As...
4. Open the sketch folder you saved in the previous "Save as" step.
5. Click the "Save" button.

Expected behavior

Don't create the nested folders.

If you try to do this in the Arduino IDE it is blocked with this dialog:

So one option would be to emulate the Java IDE behavior (but I would suggest that the obscure Borges reference be left off).

Desktop (please complete the following information):

• OS: Windows 10
• Version: 0.1.4-snapshot.3042c1a
  Date: 2021-02-08T10:04:20.854Z
  CLI Version: 0.15.1 alpha [c7403ed2]

[kittaakos]

It works perfectly on POSIX (macOS). I marked it as a Windows issue.