CLIENT: Clear errno with enabled sss-default-nss-plugin

Although errno was cleared in function sss_nss_make_request
some sss glic functions set errno with value of output argument errnop.

Reproducer:
* sssd compiled with enabled option sss-default-nss-plugin
* sss is the last value in group (/etc/nsswitch.conf)
* sssd-client is installed but sssd is stopped.

C-program:
  #include <stdio.h>
  #include <stdlib.h>
  #include <errno.h>
  #include <grp.h>

  int main(int argc, char *argv[])
  {
      struct group *p_group;

      setgrent();
      while (1) {
          errno = 0;  /* initialize for  getgrent() */
          p_group = getgrent();
          if (p_group == NULL) {
              if (errno == 0) {
                      break;   /* end of groups */
              } else {
                  perror("getgrent");
                  printf("getgrent error %d \n", errno);
                  endgrent();
                  exit(-2);
              }
          }
          printf("getgrent() OK group(%d) = %s \n",
                 p_group->gr_gid, p_group->gr_name);
      }

      exit(0);
  }

Resolves:
https://fedorahosted.org/sssd/ticket/2619

Reviewed-by: Pavel Reichl <preichl@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/sss_client/common.c b/src/sss_client/common.c
index 1b0fb1223..383572bad 100644
--- a/src/sss_client/common.c
+++ b/src/sss_client/common.c
@@ -725,6 +725,7 @@ enum nss_status sss_nss_make_request(enum sss_cli_command cmd,
     ret = sss_cli_check_socket(errnop, SSS_NSS_SOCKET_NAME);
     if (ret != SSS_STATUS_SUCCESS) {
 #ifdef NONSTANDARD_SSS_NSS_BEHAVIOUR
+        *errnop = 0;
         errno = 0;
         return NSS_STATUS_NOTFOUND;
 #else
@@ -741,6 +742,7 @@ enum nss_status sss_nss_make_request(enum sss_cli_command cmd,
     case SSS_STATUS_UNAVAIL:
     default:
 #ifdef NONSTANDARD_SSS_NSS_BEHAVIOUR
+        *errnop = 0;
         errno = 0;
         return NSS_STATUS_NOTFOUND;
 #else