commit de2b32289bf701ce3c8167a1b58436866922085e
Author: Tan Shen Joon <shen.joon.tan@intel.com>
Date:   Thu Aug 15 10:43:34 2019 +0800

    deprecate RES_USE_INET6
    
    Following the remove of RES_USE_INET6, this patch
    is cherry picked from glibc patch to adopt the similar
    fix
    
    https://sourceware.org/git/?p=glibc.git;a=commit;h=9c02d0784dfa0bb4b0bfec4fb6db35d3ea953288
    
    Signed-off-by: Tan Shen Joon <shen.joon.tan@intel.com>

diff --git a/src/nss_altfiles/files-hosts.c b/src/nss_altfiles/files-hosts.c
index 65661d8..8d31a1f 100644
--- a/src/nss_altfiles/files-hosts.c
+++ b/src/nss_altfiles/files-hosts.c
@@ -33,8 +33,8 @@
 #define DATABASE	"hosts"
 #define NEED_H_ERRNO
 
-#define EXTRA_ARGS	 , af, flags
-#define EXTRA_ARGS_DECL	 , int af, int flags
+#define EXTRA_ARGS	 , af
+#define EXTRA_ARGS_DECL	 , int af
 
 #define ENTDATA hostent_data
 struct hostent_data
@@ -59,12 +59,7 @@ LINE_PARSER
      af = af == AF_UNSPEC ? AF_INET : af;
    else
      {
-       if (af == AF_INET6 && (flags & AI_V4MAPPED) != 0
-	   && inet_pton (AF_INET, addr, entdata->host_addr) > 0)
-	 map_v4v6_address ((char *) entdata->host_addr,
-			   (char *) entdata->host_addr);
-       else if (af == AF_INET
-		&& inet_pton (AF_INET6, addr, entdata->host_addr) > 0)
+     if (af == AF_INET && inet_pton (AF_INET6, addr, entdata->host_addr) > 0)
 	 {
 	   if (IN6_IS_ADDR_V4MAPPED (entdata->host_addr))
 	     memcpy (entdata->host_addr, entdata->host_addr + 12, INADDRSZ);
@@ -97,16 +92,13 @@ LINE_PARSER
    STRING_FIELD (result->h_name, isspace, 1);
  })
 
-#define EXTRA_ARGS_VALUE \
-  , ((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET),		      \
-  ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0)
+#define EXTRA_ARGS_VALUE , AF_INET
 #include "files-XXX.c"
 #undef EXTRA_ARGS_VALUE
 
 /* We only need to consider IPv4 mapped addresses if the input to the
    gethostbyaddr() function is an IPv6 address.  */
-#define EXTRA_ARGS_VALUE \
-  , af, (len == IN6ADDRSZ ? AI_V4MAPPED : 0)
+#define EXTRA_ARGS_VALUE , af
 DB_LOOKUP (hostbyaddr, ,,,
 	   {
 	     if (result->h_length == (int) len
@@ -130,12 +122,8 @@ ALTFILES_SYMBOL1(_gethostbyname3_r) (const char *name, int af, struct hostent *r
 
   if (status == NSS_STATUS_SUCCESS)
     {
-      /* XXX Is using _res to determine whether we want to convert IPv4
-         addresses to IPv6 addresses really the right thing to do?  */
-      int flags = ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0);
-
       while ((status = internal_getent (stream, result, buffer, buflen, errnop,
-					herrnop, af, flags))
+					herrnop, af))
 	     == NSS_STATUS_SUCCESS)
 	{
 	  LOOKUP_NAME_CASE (h_name, h_aliases)
@@ -162,8 +150,7 @@ ALTFILES_SYMBOL1(_gethostbyname3_r) (const char *name, int af, struct hostent *r
 
 	again:
 	  while ((status = internal_getent (stream, &tmp_result_buf, tmp_buffer,
-					    tmp_buflen, errnop, herrnop, af,
-					    flags))
+					    tmp_buflen, errnop, herrnop, af))
 		 == NSS_STATUS_SUCCESS)
 	    {
 	      int matches = 1;
@@ -351,9 +338,7 @@ ALTFILES_SYMBOL1(_gethostbyname_r) (const char *name, struct hostent *result,
 			    char *buffer, size_t buflen, int *errnop,
 			    int *herrnop)
 {
-  int af = ((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET);
-
-  return ALTFILES_SYMBOL1(_gethostbyname3_r) (name, af, result, buffer, buflen,
+  return ALTFILES_SYMBOL1(_gethostbyname3_r) (name, AF_INET, result, buffer, buflen,
 				      errnop, herrnop, NULL, NULL);
 }
 
@@ -390,7 +375,7 @@ ALTFILES_SYMBOL1(_gethostbyname4_r) (const char *name, struct gaih_addrtuple **p
 
 	  struct hostent result;
 	  status = internal_getent (stream, &result, buffer, buflen, errnop,
-				    herrnop, AF_UNSPEC, 0);
+				    herrnop, AF_UNSPEC);
 	  if (status != NSS_STATUS_SUCCESS)
 	    break;