nss: fix nss_database_lookup2's alternate handling [BZ #27416]

__nss_database_lookup2's extra arguments were left unused in the
nsswitch reloading patch set; this broke compat (default config
ignored) and shadow files (secondary name ignored) which relies on
these fallbacks.

This patch adds in the previous behavior by correcting the
initialization of the database list to reflect the fallbacks.  This
means that the nss_database_lookup2 interface no longer needs to be
passed the fallback info, so API and callers were adjusted.

Since all callers needed to be edited anyway, the calls were changed
from __nss_database_lookup2 to the faster __nss_database_get.  This
was an intended optimization which was deferred during the initial
lookup changes to avoid touching so many files.

The test case verifies that compat targets work (passwd) and that the
default configuration works (group).  Tested on x86-64.

1 files changed, 0 insertions, 9 deletions

diff --git a/nss/nsswitch.h b/nss/nsswitch.h
index c483bbd891..ab782b605e 100644
--- a/nss/nsswitch.h
+++ b/nss/nsswitch.h
@@ -88,15 +88,6 @@ extern bool __nss_database_custom[NSS_DBSIDX_max] attribute_hidden;
 
 /* Interface functions for NSS.  */
 
-/* Get the data structure representing the specified database.
-   If there is no configuration for this database in the file,
-   parse a service list from DEFCONFIG and use that.  More
-   than one function can use the database.  */
-extern int __nss_database_lookup2 (const char *database,
-				   const char *alternative_name,
-				   const char *defconfig, struct nss_action **ni);
-libc_hidden_proto (__nss_database_lookup2)
-
 /* Put first function with name FCT_NAME for SERVICE in FCTP.  The
    position is remembered in NI.  The function returns a value < 0 if
    an error occurred or no such function exists.  */