bug#70586: cp walks dir differently than rm and is hitting "File name too long" where this could be avoided

Collin Funk <[email protected]> writes:

> It is known about, and has been mentioned in the TODO file for a very
> long time:
>
>     cp --recursive: use fts and *at functions to perform directory
>     traversals in source and destination hierarchy rather than forming
>     full file names. The latter (current) approach fails unnecessarily
>     when the names become very long, and requires space and time that is
>     quadratic in the depth of the hierarchy.
>
> I suppose very few have run into the limit with real usage.
>
> I agree it should be fixed though. I'll have a look at it.

Also, 'ls -R' has the same problem.

     $ mkdir -p `python3 -c 'print("./" + "a/" * 32768)'`
     $ ls -R a > /dev/null
     ls: cannot open directory '[long file name]': File name too long

I'll have a look at that one too. Finding a reasonable way to define the
sort functions in terms of 'FTSENT **' will not be very fun though.

Collin