Our thought about fixing the problem of cp --recursive

[Cai Xianchao]

hi, Jim

We decide to take your suggestion after researching fts and remove.c.
Use fts to perform the source-tree traversal and traverse the destination
tree by keeping two file descriptors.
Thank you for your suggestion.   :-)  

But we find some problems during our research. There are some coreutils
library functions that may fail due to ENAMETOOLONG. Such as
same_name
utimecmp
futimens
utimens
gl_futimens
euidaccess
savedir
copy_acl
set_acl
qset_acl
areadlink_with_size

Functions that call the above function(s) may fail, so we decide to
rewrite these coreutils library functions. Do you have any better
suggestions?