Thanks Tim Graham for the review.

Thanks Tim Graham for the review.

Thanks Tim Graham and Simon Charette for the reviews.

Thanks Tim Graham for the review.

Thanks revimi for the initial patch.

Fixed #27108 -- Displayed collectstatic's delete/overwrite warnings only if some files exist in STATIC_ROOT.

Thanks Tim Graham for the review.

Thanks Tim Graham for precious inputs.

Refs #26190.

Made the `manage.py help collectstatic` don't fail if the `STATIC_ROOT`
setting is empty.

This requires that each test never alters files in static directories
collected by other tests. The alternative is to add a temporary
directory to STATICFILES_DIRS or a new app to INSTALLED_APPS.