regression: smbclient authfile parameter no longer works

[pd5rm]

I was using smbclient as part of my autofs setup to enumerate remote shares. This worked fine on a previous release of Ubuntu 13.10, however when I upgraded to 14.04, my shares no longer got enumerated.

When I debugged further, I was getting logon errors. As a workground, it was suggested I modify the smb.conf file and change the workgroup setting there. This appeared to work, but doesn't make sense to me. I shouldn't need to change smb.conf (used for smbd server) for client usage. I would expect the "authfile" passed to -A to be used for authentication purposes.

Before smb.conf change:
user@workstation:/$ sudo /usr/bin/smbclient -A /etc/auto.credentials -gL <server>
session setup failed: NT_STATUS_LOGON_FAILURE

After modifying smb.conf (changed workgroup parameter to my domain name):
user@workstation:/$ sudo /usr/bin/smbclient -A /etc/auto.credentials -gL <server>
Domain=[mydomain] OS=[Windows Server 2012 R2 Standard 9600] Server=[Windows Server 2012 R2 Standard 6.3]
Disk|mysharename|
<snipped list fo sharenames>
Domain=[mydomain] OS=[Windows Server 2012 R2 Standard 9600] Server=[Windows Server 2012 R2 Standard 6.3]

My auto.credentials file is like so (as documented in smbclient manpage).
username=<username>
password=<password>
domain=<domain/workgroup>

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.