Bug report by Julien Cristau <julien.cristau@ens-lyon.org> in Debian BTS:

Package: libsmbclient
Version: 3.0.20b-2
Severity: normal
Tags: patch

Hi

when connecting to netbios shares, libsmbclient tries to cache
connections. smbc_server thus calls find_server to avoid creating
multiple connections with the same parameters. The problem is that if
find_server fails, and the subsequent call to cli_session_setup (at
libsmb/libsmbclient.c:715) fails too, it then tries to open a connection
with username = "". If this connection succeeds, it is cached, but the
username value of the cache entry is "", and the connection is never
reused, because every call to smbc_server (and thus to find_server) uses
the original username.
I think that there should either be a call to find_server(context,
server, share, workgroup, username_used, password) after username_used
has been set to "", or the connection should be cached with the original
username (which is what the attached patch does).