Git sparse-index warning should not trigger for empty directories

[ThomasFWise]

A non-trivial percentage of the time VS, VSCode, Windows Explorer, cmd.exe, etc., can have a lock on a directory and prevent git from deleting it when changes are made to which file paths are sparse checked out. When this happens, even though no files are in those directories, git still warns and expands then index slowing all commands down.

It would be nice if the index expansion could be skipped for empty directories.

[dscho]

@ThomasFWise thank you for opening this report! Would you have a simple script that initializes a repository and that would demonstrate the problem?

[ThomasFWise]

I don't have a simple script that does the repo creation and file/folder seeding, but once you have a repo with sparse-checkout the easiest way to repro the issue is:
git sparse-checkout add <FOLDER>
cd <FOLDER>
git sparse-checkout list
git sparse-checkout set --stdin <Everything from list except FOLDER>