Partial backport of the following commit, restricted to the

netgroup changes:

commit c6dfed243e0310bc3294c0fdf1816fceab024e9b

Author: Roland McGrath <roland@hack.frob.com>

Date:   Wed Oct 22 13:17:20 2014 -0700

    Rework some nscd code not to use variable-length struct types.

diff --git a/inet/netgroup.h b/inet/netgroup.h

index f3797a698d126157..fa1732762e32c2c0 100644

--- a/inet/netgroup.h

+++ b/inet/netgroup.h

@@ -26,7 +26,7 @@

 struct name_list

 {

   struct name_list *next;

-  char name[0];

+  char name[];

 };

diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c

index 7ee0c284ed58d1e3..7d7269a8edf1b99d 100644

--- a/nscd/netgroupcache.c

+++ b/nscd/netgroupcache.c

@@ -21,6 +21,7 @@

 #include <errno.h>

 #include <libintl.h>

 #include <stdbool.h>

+#include <stdlib.h>

 #include <unistd.h>

 #include <sys/mman.h>

@@ -136,11 +137,8 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,

   char *buffer = NULL;

   size_t nentries = 0;

   size_t group_len = strlen (key) + 1;

-  union

-  {

-    struct name_list elem;

-    char mem[sizeof (struct name_list) + group_len];

-  } first_needed;

+  struct name_list *first_needed

+    = alloca (sizeof (struct name_list) + group_len);

   if (netgroup_database == NULL

       && __nss_database_lookup ("netgroup", NULL, NULL, &netgroup_database))

@@ -153,9 +151,9 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,

   memset (&data, '\0', sizeof (data));

   buffer = xmalloc (buflen);

-  first_needed.elem.next = &first_needed.elem;

-  memcpy (first_needed.elem.name, key, group_len);

-  data.needed_groups = &first_needed.elem;

+  first_needed->next = first_needed;

+  memcpy (first_needed->name, key, group_len);

+  data.needed_groups = first_needed;

   while (data.needed_groups != NULL)

     {