nsswitch: handle missing actions properly

[Andreas Schwab]

On Dez 09 2020, DJ Delorie via Libc-alpha wrote:

> diff --git a/grp/initgroups.c b/grp/initgroups.c
> index a60ca1c395..a0a836d862 100644
> --- a/grp/initgroups.c
> +++ b/grp/initgroups.c
> @@ -72,11 +72,13 @@ internal_getgrouplist (const char *user, gid_t group, long int *size,
>  
>    nss_action_list nip;
>  
> -  if (__nss_database_get (nss_database_initgroups, &nip))
> +  if (__nss_database_get (nss_database_initgroups, &nip)
> +      && nip != NULL)
>      {
>        use_initgroups_entry = true;
>      }
> -  else if (__nss_database_get (nss_database_group, &nip))
> +  else if (__nss_database_get (nss_database_group, &nip)
> +      && nip != NULL)

Indentation is off here.

> diff --git a/nss/nsswitch.c b/nss/nsswitch.c
> index 40109c744d..921062e04f 100644
> --- a/nss/nsswitch.c
> +++ b/nss/nsswitch.c
> @@ -81,7 +81,7 @@ __nss_database_lookup2 (const char *database, const char *alternate_name,
>    if (database_names[database_id] == NULL)
>      return -1;
>  
> -  if (__nss_database_get (database_id, ni))
> +  if (__nss_database_get (database_id, ni) && *ni)

No implicit boolean coercion.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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