Bug 1153412

+++ This bug was initially created as a clone of Bug #1153411 +++

Description of problem:
when copy-in/copy-out a symbolic link, the two APIs only copy the link property not the real file, some times it may have no problem but some times it will have a unexpected result.

When we copy ordinary symbolic links what we want is to copy the real file, in other words the TARGET files. 
When we copy directories, in most cases we want to keep the symbolic link in a directory. One reason is we want to keep the structure in the directory the other reason is the directory may contain links refer to a large file and we don't want to copy it or other reasons. 

The best way is to add an option to copy-in and copy-out to let the users to select if they want to follow the symbolic links like rsync. If copy-in and copy-out will not add such option, then at least it should add some text in help messages to describe this problem.  The same problem exist in virt-copy-in and virt-copy-out. 


Version-Release number of selected component (if applicable):
libguestfs-1.27.62-1.1.el7


How reproducible:
100%


Steps to Reproduce:
copy-in:
1. #echo "in host" > /etc/hosts.deny
2. #ln -s /etc/hosts.deny /etc/deny_link
3. #guestfish -i -a rhel.img
><fs> copy-in /etc/deny_link /etc/
><fs> ll /etc/deny_link
lrwxrwxrwx 1 root root 15 Oct 14 14:12 /sysroot/etc/deny_link -> /etc/hosts.deny

><fs> cat /etc/hosts.deny
#
# hosts.deny    This file contains access rules which are used to
#               deny connections to network services that either use
#               the tcp_wrappers library or that have been
#               started through a tcp_wrappers-enabled xinetd.
#
#               The rules in this file can also be set up in
#               /etc/hosts.allow with a 'deny' option instead.
#
#               See 'man 5 hosts_options' and 'man 5 hosts_access'
#               for information on rule syntax.
#               See 'man tcpd' for information on tcp_wrappers
#

copy-out:
4. #guestfish -i -a rhel.img
><fs> vi /etc/hosts.deny
><fs> cat /etc/hosts.deny
in guest

><fs> ln-s /etc/hosts.deny /etc/host_deny_link
><fs> copy-out  /etc/ .
><fs> quit
5. #ll etc/host_deny_link
lrwxrwxrwx. 1 root root 15 Oct 14 22:15 etc/host_deny_link -> /etc/hosts.deny
6. #cat etc/host_deny_link
in host


Actual results:
copy-in and copy-out only copy the link property not copy the real file.


Expected results:
At step 3, ><fs> cat /etc/hosts.deny should output "in host"
At step 6, #cat etc/host_deny_link should output "in guest"
copy-in and copy-out should copy the real file.


Additional info: