Change getfacl to print ACL group: (and user:) entries using %u instead of %d?

Ran into this the other day (also reported as bug 295444):
# mkdir testdir
# chgrp 3000000005 testdir

# setfacl -x 1 -a 1 group:3000000005:full_set:fd:allow testdir 

# getfacl testdir
# file: testdir
# owner: root
# group: 3000000005
            owner@:rwxpDdaARWcCos:fd-----:allow
 group:-1294967291:rwxpDdaARWcCos:fd-----:allow


Looking at the code in /usr/src/lib/libc/posix1e/acl_to_text_nfs4.c it isn't so surprising:

                if (grp == NULL)
                        snprintf(str, size, "group:%d", (unsigned int)*id);
                else
                        snprintf(str, size, "group:%s", grp->gr_name);
    
(and similar for user:)

uid_t/gid_t are an unsigned 32bit integers on most (all?, at least FreeBSD, Linux, MacOS & Solaris) modern Unix systems, so should be printed using "%u" instead… (In my opinion).


The current code makes it difficult to use scripts to extract ACL entries and copy them correctly to new files:

# mkdir newdir
# getfacl testdir | setfacl -b -n -M - newdir
setfacl: malformed ACL: unknown user or group name "-1294967291"
setfacl: -: get_acl_from_file() failed: Invalid argument



Which is due to it being impossible to set it using the "signed" variant:

# setfacl -x 1 -a 1 group:-1294967291:full_set:fd:allow td
setfacl: malformed ACL: unknown user or group name "-1294967291"


A quick look in the acl_id_to_name.c file used for POSIX ACLs seems to indicate similar %d usage.


I think the right way to fix this is to change %d to %u when printing uid_t & gid_t in ACL entries (and since most people are sane enough to not use uid/gid's over 2 billion not many will have noticed this :-).
- Peter