bug#11449: RFE: support `install -D` with directory target

[Jan Engelhardt]

Hi.


Using cp, one can for example execute

        cp foo/bar.txt /tmp/foo/

to have /tmp/foo/bar.txt in place after a successful copy operation, 
provided the directory /tmp/foo exists. If it does not, one has to mkdir 
it beforehand naturally. I thought that using `install -D` would remedy 
this, however found that, in coreutils up to including 8.16,

        install -D foo/bar.txt /tmp/foo/

is not implemented - the program returns the error

        install: target `/tmp/foo/' is not a directory: No such file or 
        directory

On the other hand, the following command succeeds:

        install -D foo/bar.txt /fmp/foo/bar.txt

Specifying the file's basename again on the target side argument 
(/tmp/foo/bar.txt) seems redundant, given install is "just a spruced-up 
cp".
Would you consider enhancing install to support "/tmp/foo/"?


thanks,
Jan