[PATCH COMMITTED] resolv: Remove RES_NOIP6DOTINT and its implementation

[fweimer@redhat.com (Florian Weimer)]

2016-10-07  Florian Weimer  <fweimer@redhat.com>

	resolv: Remove RES_NOIP6DOTINT and its implementation.
	* resolv/resolv.h (RES_DEFAULT): Remove RES_NOIP6DOTINT.
	(RES_NOIP6DOTINT): Remove.
	* resolv/gethnamaddr.c (gethostbyaddr): Remove RES_NOIP6DOTINT
	handling.
	* resolv/res_debug.c (p_option): Likewise.
	* resolv/res_init.c (res_setoptions): Likewise.
	* resolv/nss_dns/dns-host.c (_nss_dns_gethostbyaddr2_r): Likewise.

diff --git a/NEWS b/NEWS
index be66f23..49b9180 100644
--- a/NEWS
+++ b/NEWS
@@ -59,6 +59,11 @@ Version 2.25
   for the Linux quota interface which predates kernel version 2.4.22 has
   been removed.
 
+* The “ip6-dotint” and “no-ip6-dotint” resolver options, and the
+  corresponding RES_NOIP6DOTINT flag from <resolv.h> have been removed.
+  “no-ip6-dotint” had already been the default, and support for the
+  “ip6-dotint” option was removed from the Internet in 2006.
+
 * The flags RES_AAONLY, RES_PRIMARY, RES_NOCHECKNAME, RES_KEEPTSIG defined
   in the <resolv.h> header file have been deprecated.  They were already
   unimplemented.
diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c
index 9ad2c30..1b81ca8 100644
--- a/resolv/gethnamaddr.c
+++ b/resolv/gethnamaddr.c
@@ -642,12 +642,6 @@ gethostbyaddr (const void *addr, socklen_t len, int af)
 
 	n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf, 1024,
 			      &buf.ptr, NULL, NULL, NULL, NULL);
-	if (n < 0 && af == AF_INET6 && (_res.options & RES_NOIP6DOTINT) == 0) {
-		strcpy(qp, "ip6.int");
-		n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf,
-				      buf.buf != orig_buf ? MAXPACKET : 1024,
-				      &buf.ptr, NULL, NULL, NULL, NULL);
-	}
 	if (n < 0) {
 		if (buf.buf != orig_buf)
 			free (buf.buf);
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index 5f9e357..b6245ad 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -495,14 +495,6 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
 
   n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
 			 1024, &host_buffer.ptr, NULL, NULL, NULL, NULL);
-  if (n < 0 && af == AF_INET6 && (_res.options & RES_NOIP6DOTINT) == 0)
-    {
-      strcpy (qp, "ip6.int");
-      n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer.buf->buf,
-			     host_buffer.buf != orig_host_buffer
-			     ? MAXPACKET : 1024, &host_buffer.ptr,
-			     NULL, NULL, NULL, NULL);
-    }
   if (n < 0)
     {
       *h_errnop = h_errno;
diff --git a/resolv/res_debug.c b/resolv/res_debug.c
index 825e8a6..0404646 100644
--- a/resolv/res_debug.c
+++ b/resolv/res_debug.c
@@ -559,7 +559,6 @@ p_option(u_long option) {
 	case RES_ROTATE:	return "rotate";
 	case RES_BLAST:		return "blast";
 	case RES_USEBSTRING:	return "ip6-bytestring";
-	case RES_NOIP6DOTINT:	return "no-ip6-dotint";
 	case RES_USE_EDNS0:	return "edns0";
 	case RES_SNGLKUP:	return "single-request";
 	case RES_SNGLKUPREOP:	return "single-request-reopen";
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 1cfa4e6..12afb9e 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -439,8 +439,6 @@ res_setoptions(res_state statp, const char *options, const char *source) {
 #define STRnLEN(str) str, sizeof (str) - 1
 		    { STRnLEN ("inet6"), 0, RES_USE_INET6 },
 		    { STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING },
-		    { STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT },
-		    { STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT },
 		    { STRnLEN ("rotate"), 0, RES_ROTATE },
 		    { STRnLEN ("edns0"), 0, RES_USE_EDNS0 },
 		    { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP },
diff --git a/resolv/resolv.h b/resolv/resolv.h
index 9146258..11a7fed 100644
--- a/resolv/resolv.h
+++ b/resolv/resolv.h
@@ -199,8 +199,6 @@ struct res_sym {
 #define	RES_BLAST	0x00020000	/* blast all recursive servers */
 #define RES_USEBSTRING	0x00040000	/* IPv6 reverse lookup with byte
 					   strings */
-#define RES_NOIP6DOTINT	0x00080000	/* Do not use .ip6.int in IPv6
-					   reverse lookup */
 #define RES_USE_EDNS0	0x00100000	/* Use EDNS0.  */
 #define RES_SNGLKUP	0x00200000	/* one outstanding request at a time */
 #define RES_SNGLKUPREOP	0x00400000	/* -"-, but open new socket for each
@@ -209,7 +207,7 @@ struct res_sym {
 #define RES_NOTLDQUERY	0x01000000	/* Do not look up unqualified name
 					   as a TLD.  */
 
-#define RES_DEFAULT	(RES_RECURSE|RES_DEFNAMES|RES_DNSRCH|RES_NOIP6DOTINT)
+#define RES_DEFAULT	(RES_RECURSE|RES_DEFNAMES|RES_DNSRCH)
 
 /*
  * Resolver "pfcode" values.  Used by dig.