Created attachment 849828 [details]
Suggested patch series

Storing and restoring ACLs in tar archives should be improved:


(1) tar archive creation with "--numeric-owner" option:

In this case, users are expectiing that the archive does not contain any symbolic owner name, so it can be extracted to an emoty hard disc on a system bootet e. g. by a rescue cd from Redhat. Current sitation is that ACLs still include the symbolic owner and not the numeric owner.


This is quite trivial to fix:

Replace all ocurences of "val = acl_to_text(acl, &len);" by "val = acl_to_any_text(acl, 0, ',', ( numeric_owner_option?TEXT_NUMERIC_IDS:0));" and followed by "len=strlen(val);" after the "if (!val)" error-handling.



Effect: Numeric owner is stored.

I'd like to note that this improvement is essential to me.



(2a) tar archive creation without "--numeric-owner" option:

In GNU tar 1.26, for every file the owner is stored both, symbolic and numeric. I would expect that ACLs are stored in both ways, too. star shows us how to do that:


star stores the numeric owner in a forth field of an acl: (e.g. "u:msteinbo:rwx:500").




(2b) tar extract should use the 4th field (discussed in point 2) in presence of "-numeric-owner".


This together with point (2) enabled users to restore an backup created without numeric owner option on a clean hard disc without passwd entries for the users (let's assume that /etc/passwd is contained in the archive so the operation makes sense).

I'd like to mention that this point would increase star compatibility a lot.



(see also http://lists.gnu.org/archive/html/bug-tar/2013-03/msg00021.html
upstream maintainer "Paul Eggert" says in
http://lists.gnu.org/archive/html/bug-tar/2013-04/msg00024.html:
"That sort of thing all sounds reasonable, I guess. I'd like Sergey's opinion though.".

In the meantime, I have reworked the patches so that do not contain any code I do not have copyright for. 


The patches are made to apply on version "1.27.1-1.fc21".