rev-list --sparse?

I was reviewing the rev-list documentation and it struck me that
dense/sparse command line flag do not make much sense.

Since dense is by default in effect, --dense is a no-op.  One
possible use of it would be to hardcode --dense on a rev-list
command line in a script, like:

	git-rev-list $some_opts --dense $some_paths

to defeat user-supplied --sparse that can be in $some_opts, but
for this to work the script needs to have parsed out user input
into some_opts and some_paths in the first place anyway, so it
can just detect and remove --sparse just as easily.

The --sparse flag does not seem to have much use either; not
giving pathspec has the same effect.