Description of problem:
 The _collect_resolv_conf_data() function limits the number of search entries to 6 within the following code snippet. Taken from the 1.10.2-16 source revision:

        /* Per 'man resolv.conf', the search list is limited to 6 domains
         * totalling 256 characters.
         */
        num = MIN (rc.searches->len, 6u);
        for (i = 0, len = 0; i < num; i++) {
                len += strlen (rc.searches->pdata[i]) + 1; /* +1 for spaces */
                if (len > 256)
                        break;
        }
        g_ptr_array_set_size (rc.searches, i);

This is no longer the limit for later RHEL releases. The limit was removed with the efforts in RHBZ677316 [^1] and released in upstream glibc-2.26 [^2].

Version-Release number of selected component (if applicable):
 # rpm -q NetworkManager
 NetworkManager-1.10.2-16.el7_5.x86_64

How reproducible:
 Easily

Steps to Reproduce:
1. Set an interface to a ipv4.dns-search entry greater than 6
    # nmcli con modify System\ eth0 ipv4.dns-search $(echo {a..g}.redhat.com, | sed -e 's/ //g' -e 's/,$//g')
    
2. Verify the ipv4.dns-search field includes more than 6 entries

    # nmcli con show System\ eth0 | grep ipv4.dns-search
    ipv4.dns-search:                        a.redhat.com,b.redhat.com,c.redhat.com,d.redhat.com,e.redhat.com,f.redhat.com,g.redhat.com

3. Issue an "nmcli con up <interface>" and verify that the /etc/resolv.conf has more than 6 entries

    # nmcli con up System\ eth0
    # grep search /etc/resolv.conf

Actual results:
    search a.redhat.com b.redhat.com c.redhat.com d.redhat.com e.redhat.com f.redhat.com


Expected results:
    search a.redhat.com b.redhat.com c.redhat.com d.redhat.com e.redhat.com f.redhat.com g.redhat.com


Additional info:
 The problem is not seen when disabling NetworkManager and falling back to the underlying network initscripts.

    # systemctl stop NetworkManager && systemctl restart network && grep search 
    /etc/resolv.conf
search a.redhat.com b.redhat.com c.redhat.com d.redhat.com e.redhat.com f.redhat.com g.redhat.com

 The problem is also present with the latest available upstream NetworkManager revision [^3].

[^1]: https://bugzilla.redhat.com/show_bug.cgi?id=677316
[^2]: https://sourceware.org/ml/libc-alpha/2017-08/msg00010.html
[^3]: https://gitlab.freedesktop.org/NetworkManager/NetworkManager/blob/master/src/dns/nm-dns-manager.c#L1132