NSS: check for overrides before calling backend

Currently the flag that the input data in a user or group lookup request
might be an override value is only set if no cached entry was found. If
the cached entry of an object with overrides is expired and a request
with the override value as input is processed the flag is not set and
the backend might not be able to find the right entry on the server.
Typically this should not happen because of mid-point refreshes. To
reproduce this create a FreeIPA user and override the login name for a
specific view. On a client which has this view applied call

getent passwd overridename
sss_cache -E
getent passwd overridename

The second getent command will still show the right output but in the
logs a

[sss_dp_get_reply] (0x1000): Got reply from Data Provider - DP error
 code: 3 errno: 0 error message: Account info lookup failed

message can be found for the second request.

Related to https://fedorahosted.org/sssd/ticket/2642

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
(cherry picked from commit 35b178d02dfd293778aefbc0b465a5a3a4b6cd8f)
(cherry picked from commit a4a447b7bf394ded65c8ae872832e7cd135425d1)

0 files changed, 0 insertions, 0 deletions