Question about TODO list

[Peter Eisentraut]

I see in the TODO list this item:

** AC_PROG_INSTALL
This test should be extended to check that install supports the GNU
Install syntax: install FILES... DIR.  This will relieve everybody
form having to use mkinstalldirs to create the directories, as install
does it itself.  install-sh is already handling this case.

However, install-sh contains this comment:

# This script is compatible with the BSD install script, but was written
# from scratch.  It can only install one file at a time, a restriction
# shared with many OS's install programs.

That seems to contradict the above.

Also, I'm not clear how writing

$(INSTALL) file1 file2 ... dir

will make mkinstalldirs obsolete, because "dir" still has to exist in 
that case and needs to be create beforehand.

Can someone clarify this?