Re: [PATCH v4 01/20] sparse-index: design doc and format update

SZEDER Gábor [off-list ref] writes:

quoted

+To start, we use a new repository extension, `extensions.sparseIndex`, to
+allow inserting sparse-directory entries into indexes with file format
+versions 2, 3, and 4. This prevents Git versions that do not understand
+the sparse-index from operating on one, but it also prevents other
+operations that do not use the index at all.

Why is this not a non-optional index extension?  ...
This really should be a non-optional index extension.

Yeah, the index extension mechanism was designed with optional and
required kinds because we wanted to support exactly a use case like
this one.

Thanks for pointing it out.