Opening projects with large file count causes issues (too many tabs)

[ubidefeo]

Describe the bug
Projects such as Marlin 3D printer firmware contain a large amount of files.
To allow users to compile this in Arduino IDE (Marlin suggests to use the Makefile or PlatformIO for compilation) and not show the 1600+ tabs, most files have been moved into a subfolder named src.
When the IDE requests the file list to the CLI, it obtains a full list because of recursion.
Such recursion should not be permitted and only the content inside the root of the sketch folder should be returned.
On my machine it’s been opening the project for the past 15 minutes... and counting.

To Reproduce
Steps to reproduce the behavior:

1. Download Marlin 2 https://github.com/MarlinFirmware/Marlin
2. Copy the folder Marlin to your Sketchbook
3. Launch IDE Pro
4. Open the Marlin Sketch
5. Leave the house and come back next week 😁
6. The tabs will keep opening

Expected behavior
Only 4 tabs should appear (the 4 supported files in the Sketch):

• Marlin.ino
• Configuration.h
• Configuration_adv.h
• Version.h

Screenshots

IDE Pro

IDE Java

Desktop (please complete the following information):

• OS: Windows/Mac/Linux
• Version: 0.1.3-nightly.20210204

Additional context
Opened a related issue for the CLI arduino/arduino-cli#1173

[ubidefeo]

@kittaakos I have assigned this to you just for tracking reasons, but if the CLI returns the correct list in theory you won't have to do anything

[kittaakos]

This issue is the duplicate of https://github.com/arduino/arduino-pro-ide/issues/373. It's a CLI issue.

[kittaakos]

but if the CLI returns the correct list in theory you won't have to do anything

Yes.

Closing, it's a duplicate.