Merge branch 'baseline' into refs/top-bases/tschwinge/Roger_Whittaker

30 files changed, 487 insertions, 359 deletions

diff --git a/resolv/Depend b/resolv/Depend
index 5c6ec03451..c29ffb5e96 100644
--- a/resolv/Depend
+++ b/resolv/Depend
@@ -1,3 +1,2 @@
-linuxthreads
 nptl
 libpthread
diff --git a/resolv/Makefile b/resolv/Makefile
index b96b8ed927..1dcb75f7c7 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1994-2014 Free Software Foundation, Inc.
+# Copyright (C) 1994-2015 Free Software Foundation, Inc.
 # This file is part of the GNU C Library.
 
 # The GNU C Library is free software; you can redistribute it and/or
@@ -20,6 +20,8 @@
 #
 subdir	:= resolv
 
+include ../Makeconfig
+
 headers	:= resolv.h \
 	   netdb.h bits/netdb.h \
 	   arpa/nameser.h arpa/nameser_compat.h \
@@ -31,14 +33,13 @@ routines := herror inet_addr inet_ntop inet_pton nsap_addr res_init \
 tests = tst-aton tst-leaks tst-inet_ntop
 xtests = tst-leaks2
 
-generate := mtrace-tst-leaks tst-leaks.mtrace tst-leaks2.mtrace
-
-include ../Makeconfig
+generate := mtrace-tst-leaks.out tst-leaks.mtrace tst-leaks2.mtrace
 
 extra-libs := libresolv libnss_dns
 ifeq ($(have-thread-library),yes)
 extra-libs += libanl
 routines += gai_sigqueue
+tests += tst-res_hconf_reorder
 endif
 extra-libs-others = $(extra-libs)
 libresolv-routines := gethnamaddr res_comp res_debug	\
@@ -64,8 +65,22 @@ ifeq (yesyes,$(build-shared)$(have-thread-library))
 tests: $(objpfx)ga_test
 endif
 
-generated := mtrace-tst-leaks tst-leaks.mtrace \
-	     mtrace-tst-leaks2 tst-leaks2.mtrace
+ifeq ($(run-built-tests),yes)
+ifneq (no,$(PERL))
+tests-special += $(objpfx)mtrace-tst-leaks.out
+xtests-special += $(objpfx)mtrace-tst-leaks2.out
+endif
+endif
+
+ifeq (,$(filter sunrpc,$(subdirs)))
+# The netdb.h we install does '#include <rpc/netdb.h>', so one must exist.
+# If sunrpc/ is built in this configuration, it installs a real <rpc/netdb.h>.
+# If that's not going to happen, install our dummy file.
+headers += rpc/netdb.h
+endif
+
+generated += mtrace-tst-leaks.out tst-leaks.mtrace \
+	     mtrace-tst-leaks2.out tst-leaks2.mtrace
 
 include ../Rules
 
@@ -91,21 +106,16 @@ $(objpfx)libanl.so: $(shared-thread-library)
 
 $(objpfx)ga_test: $(objpfx)libanl.so $(shared-thread-library)
 
+$(objpfx)tst-res_hconf_reorder: $(libdl) $(shared-thread-library)
+tst-res_hconf_reorder-ENV = RESOLV_REORDER=on
+
 $(objpfx)tst-leaks: $(objpfx)libresolv.so
 tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace
-$(objpfx)mtrace-tst-leaks: $(objpfx)tst-leaks.out
-	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@
-ifeq ($(run-built-tests),yes)
-ifneq (no,$(PERL))
-tests: $(objpfx)mtrace-tst-leaks
-endif
-endif
+$(objpfx)mtrace-tst-leaks.out: $(objpfx)tst-leaks.out
+	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@; \
+	$(evaluate-test)
 
 tst-leaks2-ENV = MALLOC_TRACE=$(objpfx)tst-leaks2.mtrace
-$(objpfx)mtrace-tst-leaks2: $(objpfx)tst-leaks2.out
-	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks2.mtrace > $@
-ifeq ($(run-built-tests),yes)
-ifneq (no,$(PERL))
-xtests: $(objpfx)mtrace-tst-leaks2
-endif
-endif
+$(objpfx)mtrace-tst-leaks2.out: $(objpfx)tst-leaks2.out
+	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks2.mtrace > $@; \
+	$(evaluate-test)
diff --git a/resolv/Versions b/resolv/Versions
index 6f02597372..e561bce1a4 100644
--- a/resolv/Versions
+++ b/resolv/Versions
@@ -1,5 +1,3 @@
-%include <tls.h>
-
 libc {
   GLIBC_2.0 {
     _res;
@@ -26,7 +24,7 @@ libc {
   GLIBC_PRIVATE {
     __gai_sigqueue;
 
-    h_errno; __resp;
+    __h_errno; __resp;
 
     __res_maybe_init; __res_iclose;
   }
diff --git a/resolv/gai_cancel.c b/resolv/gai_cancel.c
index caf31455a2..6be2e5b16d 100644
--- a/resolv/gai_cancel.c
+++ b/resolv/gai_cancel.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
diff --git a/resolv/gai_error.c b/resolv/gai_error.c
index e8d1baa1b5..085c82e1b9 100644
--- a/resolv/gai_error.c
+++ b/resolv/gai_error.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
diff --git a/resolv/gai_misc.c b/resolv/gai_misc.c
index 9c53876bf9..0244b20c69 100644
--- a/resolv/gai_misc.c
+++ b/resolv/gai_misc.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
diff --git a/resolv/gai_misc.h b/resolv/gai_misc.h
index b87b9e3d32..92f968830c 100644
--- a/resolv/gai_misc.h
+++ b/resolv/gai_misc.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
@@ -31,7 +31,7 @@ struct waitlist
 #ifndef DONT_NEED_GAI_MISC_COND
     pthread_cond_t *cond;
 #endif
-    volatile int *counterp;
+    volatile unsigned int *counterp;
     /* The next field is used in asynchronous `lio_listio' operations.  */
     struct sigevent *sigevp;
     /* XXX See requestlist, it's used to work around the broken signal
diff --git a/resolv/gai_notify.c b/resolv/gai_notify.c
index 7bee10211b..ab048620da 100644
--- a/resolv/gai_notify.c
+++ b/resolv/gai_notify.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
diff --git a/resolv/gai_sigqueue.c b/resolv/gai_sigqueue.c
index f6e391c729..e2c78785eb 100644
--- a/resolv/gai_sigqueue.c
+++ b/resolv/gai_sigqueue.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/resolv/gai_suspend.c b/resolv/gai_suspend.c
index b795cdecb8..c3a1288360 100644
--- a/resolv/gai_suspend.c
+++ b/resolv/gai_suspend.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
@@ -35,7 +35,7 @@ gai_suspend (const struct gaicb *const list[], int ent,
   pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
 #endif
   int cnt;
-  int cntr = 1;
+  unsigned int cntr = 1;
   int none = 1;
   int result;
 
diff --git a/resolv/getaddrinfo_a.c b/resolv/getaddrinfo_a.c
index 38b48c627e..e6372228c9 100644
--- a/resolv/getaddrinfo_a.c
+++ b/resolv/getaddrinfo_a.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
 
@@ -28,7 +28,7 @@
 /* We need this special structure to handle asynchronous I/O.  */
 struct async_waitlist
   {
-    int counter;
+    unsigned int counter;
     struct sigevent sigev;
     struct waitlist list[0];
   };
@@ -40,7 +40,7 @@ getaddrinfo_a (int mode, struct gaicb *list[], int ent, struct sigevent *sig)
   struct sigevent defsigev;
   struct requestlist *requests[ent];
   int cnt;
-  volatile int total = 0;
+  volatile unsigned int total = 0;
   int result = 0;
 
   /* Check arguments.  */
diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c
index 1fd8f92680..7fd0e497b1 100644
--- a/resolv/gethnamaddr.c
+++ b/resolv/gethnamaddr.c
@@ -49,6 +49,11 @@
  * --Copyright--
  */
 
+/* XXX This file is not used by any of the resolver functions implemented by
+   glibc (i.e. get*info and gethostby*).  It cannot be removed however because
+   it exports symbols in the libresolv ABI.  The file is not maintained any
+   more, nor are these functions.  */
+
 #if defined(LIBC_SCCS) && !defined(lint)
 static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
 #endif /* LIBC_SCCS and not lint */
@@ -326,23 +331,18 @@ getanswer (const querybuf *answer, int anslen, const char *qname, int qtype)
 			buflen -= n;
 			continue;
 		}
-		if ((type == T_SIG) || (type == T_KEY) || (type == T_NXT)) {
-			/* We don't support DNSSEC yet.  For now, ignore
-			 * the record and send a low priority message
-			 * to syslog.
-			 */
-			syslog(LOG_DEBUG|LOG_AUTH,
-	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
-			       qname, p_class(C_IN), p_type(qtype),
-			       p_type(type));
-			cp += n;
-			continue;
-		}
 		if (type != qtype) {
-			syslog(LOG_NOTICE|LOG_AUTH,
+			/* Log a low priority message if we get an unexpected
+			 * record, but skip it if we are using DNSSEC since it
+			 * uses many different types in responses that do not
+			 * match QTYPE.
+			 */
+			if ((_res.options & RES_USE_DNSSEC) == 0) {
+				syslog(LOG_NOTICE|LOG_AUTH,
 	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
-			       qname, p_class(C_IN), p_type(qtype),
-			       p_type(type));
+					qname, p_class(C_IN), p_type(qtype),
+					p_type(type));
+			}
 			cp += n;
 			continue;		/* XXX - had_error++ ? */
 		}
@@ -621,7 +621,7 @@ gethostbyname2(name, af)
 	buf.buf = origbuf = (querybuf *) alloca (1024);
 
 	if ((n = __libc_res_nsearch(&_res, name, C_IN, type, buf.buf->buf, 1024,
-				    &buf.ptr, NULL, NULL, NULL)) < 0) {
+				    &buf.ptr, NULL, NULL, NULL, NULL)) < 0) {
 		if (buf.buf != origbuf)
 			free (buf.buf);
 		Dprintf("res_nsearch failed (%d)\n", n);
@@ -667,8 +667,8 @@ gethostbyaddr(addr, len, af)
 		return (NULL);
 	}
 	if (af == AF_INET6 && len == IN6ADDRSZ &&
-	    (!bcmp(uaddr, mapped, sizeof mapped) ||
-	     !bcmp(uaddr, tunnelled, sizeof tunnelled))) {
+	    (!memcmp(uaddr, mapped, sizeof mapped) ||
+	     !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
 		/* Unmap. */
 		addr += sizeof mapped;
 		uaddr += sizeof mapped;
@@ -716,12 +716,12 @@ gethostbyaddr(addr, len, af)
 	buf.buf = orig_buf = (querybuf *) alloca (1024);
 
 	n = __libc_res_nquery(&_res, qbuf, C_IN, T_PTR, buf.buf->buf, 1024,
-			      &buf.ptr, NULL, NULL, NULL);
+			      &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);
+				      &buf.ptr, NULL, NULL, NULL, NULL);
 	}
 	if (n < 0) {
 		if (buf.buf != orig_buf)
@@ -917,7 +917,7 @@ _gethtbyaddr(addr, len, af)
 
 	_sethtent(0);
 	while ((p = _gethtent()))
-		if (p->h_addrtype == af && !bcmp(p->h_addr, addr, len))
+		if (p->h_addrtype == af && !memcmp(p->h_addr, addr, len))
 			break;
 	_endhtent();
 	return (p);
diff --git a/resolv/inet_addr.c b/resolv/inet_addr.c
index 144b87a74c..ee42093754 100644
--- a/resolv/inet_addr.c
+++ b/resolv/inet_addr.c
@@ -90,13 +90,14 @@ static const char rcsid[] = "$BINDId: inet_addr.c,v 8.11 1999/10/13 16:39:25 vix
  * The value returned is in network order.
  */
 in_addr_t
-inet_addr(const char *cp) {
+__inet_addr(const char *cp) {
 	struct in_addr val;
 
 	if (__inet_aton(cp, &val))
 		return (val.s_addr);
 	return (INADDR_NONE);
 }
+weak_alias (__inet_addr, inet_addr)
 
 /*
  * Check whether "cp" is a valid ascii representation
diff --git a/resolv/inet_pton.c b/resolv/inet_pton.c
index c507013e4e..3d8819512e 100644
--- a/resolv/inet_pton.c
+++ b/resolv/inet_pton.c
@@ -49,7 +49,7 @@ static int inet_pton6 (const char *src, u_char *dst) internal_function;
  *	Paul Vixie, 1996.
  */
 int
-inet_pton(af, src, dst)
+__inet_pton(af, src, dst)
 	int af;
 	const char *src;
 	void *dst;
@@ -65,7 +65,9 @@ inet_pton(af, src, dst)
 	}
 	/* NOTREACHED */
 }
-libc_hidden_def (inet_pton)
+libc_hidden_def (__inet_pton)
+weak_alias (__inet_pton, inet_pton)
+libc_hidden_weak (inet_pton)
 
 /* int
  * inet_pton4(src, dst)
diff --git a/resolv/netdb.h b/resolv/netdb.h
index f9e2bf00cb..44cf6923b2 100644
--- a/resolv/netdb.h
+++ b/resolv/netdb.h
@@ -1,4 +1,4 @@
-  /* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+  /* Copyright (C) 1996-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -70,7 +70,7 @@ extern int *__h_errno_location (void) __THROW __attribute__ ((__const__));
 # define NO_DATA	4	/* Valid name, no data record of requested
 				   type.  */
 #endif
-#if defined __USE_MISC || defined __USE_GNU
+#ifdef __USE_MISC
 # define NETDB_INTERNAL	-1	/* See errno.  */
 # define NETDB_SUCCESS	0	/* No problem.  */
 # define NO_ADDRESS	NO_DATA	/* No address, look for MX record.  */
@@ -104,7 +104,7 @@ struct hostent
   int h_addrtype;		/* Host address type.  */
   int h_length;			/* Length of address.  */
   char **h_addr_list;		/* List of addresses from name server.  */
-#if defined __USE_MISC || defined __USE_GNU
+#ifdef __USE_MISC
 # define	h_addr	h_addr_list[0] /* Address, for backward compatibility.*/
 #endif
 };
@@ -436,7 +436,7 @@ extern int getnetgrent_r (char **__restrict __hostp,
 #endif	/* misc */
 
 
-#ifdef __USE_BSD
+#ifdef __USE_MISC
 /* Call `rshd' at port RPORT on remote machine *AHOST to execute CMD.
    The local user is LOCUSER, on the remote machine the command is
    executed as REMUSER.  In *FD2P the descriptor to the socket for the
@@ -561,8 +561,8 @@ extern int rresvport_af (int *__alport, sa_family_t __af);
 #endif
 
 
-/* Extension from POSIX.1g.  */
-#ifdef	__USE_POSIX
+/* Extension from POSIX.1:2001.  */
+#ifdef __USE_XOPEN2K
 /* Structure to contain information about address of a service provider.  */
 struct addrinfo
 {
diff --git a/resolv/nss_dns/dns-canon.c b/resolv/nss_dns/dns-canon.c
index a9db232c7b..14ddd6cca0 100644
--- a/resolv/nss_dns/dns-canon.c
+++ b/resolv/nss_dns/dns-canon.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2004-2014 Free Software Foundation, Inc.
+/* Copyright (C) 2004-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
 
@@ -62,7 +62,7 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
     {
       int r = __libc_res_nquery (&_res, name, ns_c_in, qtypes[i],
 				 buf, sizeof (buf), &ansp.ptr, NULL, NULL,
-				 NULL);
+				 NULL, NULL);
       if (r > 0)
 	{
 	  /* We need to decode the response.  Just one question record.
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index f8f192e5af..357ac04693 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+/* Copyright (C) 1996-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
@@ -190,7 +190,7 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
   host_buffer.buf = orig_host_buffer = (querybuf *) alloca (1024);
 
   n = __libc_res_nsearch (&_res, name, C_IN, type, host_buffer.buf->buf,
-			  1024, &host_buffer.ptr, NULL, NULL, NULL);
+			  1024, &host_buffer.ptr, NULL, NULL, NULL, NULL);
   if (n < 0)
     {
       switch (errno)
@@ -225,7 +225,7 @@ _nss_dns_gethostbyname3_r (const char *name, int af, struct hostent *result,
 	n = __libc_res_nsearch (&_res, name, C_IN, T_A, host_buffer.buf->buf,
 				host_buffer.buf != orig_host_buffer
 				? MAXPACKET : 1024, &host_buffer.ptr,
-				NULL, NULL, NULL);
+				NULL, NULL, NULL, NULL);
 
       if (n < 0)
 	{
@@ -308,13 +308,20 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
   u_char *ans2p = NULL;
   int nans2p = 0;
   int resplen2 = 0;
+  int ans2p_malloced = 0;
 
   int olderr = errno;
   enum nss_status status;
   int n = __libc_res_nsearch (&_res, name, C_IN, T_UNSPEC,
 			      host_buffer.buf->buf, 2048, &host_buffer.ptr,
-			      &ans2p, &nans2p, &resplen2);
-  if (n < 0)
+			      &ans2p, &nans2p, &resplen2, &ans2p_malloced);
+  if (n >= 0)
+    {
+      status = gaih_getanswer (host_buffer.buf, n, (const querybuf *) ans2p,
+			       resplen2, name, pat, buffer, buflen,
+			       errnop, herrnop, ttlp);
+    }
+  else
     {
       switch (errno)
 	{
@@ -341,16 +348,11 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
 	*errnop = EAGAIN;
       else
 	__set_errno (olderr);
-
-      if (host_buffer.buf != orig_host_buffer)
-	free (host_buffer.buf);
-
-      return status;
     }
 
-  status = gaih_getanswer(host_buffer.buf, n, (const querybuf *) ans2p,
-			  resplen2, name, pat, buffer, buflen,
-			  errnop, herrnop, ttlp);
+  /* Check whether ans2p was separately allocated.  */
+  if (ans2p_malloced)
+    free (ans2p);
 
   if (host_buffer.buf != orig_host_buffer)
     free (host_buffer.buf);
@@ -398,7 +400,7 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
  buffer += pad;
  buflen = buflen > pad ? buflen - pad : 0;
 
- if (__builtin_expect (buflen < sizeof (struct host_data), 0))
+ if (__glibc_unlikely (buflen < sizeof (struct host_data)))
    {
      *errnop = ERANGE;
      *h_errnop = NETDB_INTERNAL;
@@ -452,7 +454,7 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
       break;
     case AF_INET6:
       /* Only lookup with the byte string format if the user wants it.  */
-      if (__builtin_expect (_res.options & RES_USEBSTRING, 0))
+      if (__glibc_unlikely (_res.options & RES_USEBSTRING))
 	{
 	  qp = stpcpy (qbuf, "\\[x");
 	  for (n = 0; n < IN6ADDRSZ; ++n)
@@ -460,7 +462,7 @@ _nss_dns_gethostbyaddr2_r (const void *addr, socklen_t len, int af,
 	  strcpy (qp, "].ip6.arpa");
 	  n = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR,
 				 host_buffer.buf->buf, 1024, &host_buffer.ptr,
-				 NULL, NULL, NULL);
+				 NULL, NULL, NULL, NULL);
 	  if (n >= 0)
 	    goto got_it_already;
 	}
@@ -481,14 +483,14 @@ _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);
+			 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, NULL, NULL, NULL);
     }
   if (n < 0)
     {
@@ -613,7 +615,8 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
   int have_to_map = 0;
   uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct host_data);
   buffer += pad;
-  if (__builtin_expect (buflen < sizeof (struct host_data) + pad, 0))
+  buflen = buflen > pad ? buflen - pad : 0;
+  if (__glibc_unlikely (buflen < sizeof (struct host_data)))
     {
       /* The buffer is too small.  */
     too_small:
@@ -727,14 +730,14 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  n = -1;
 	}
 
-      if (__builtin_expect (n < 0 || (*name_ok) (bp) == 0, 0))
+      if (__glibc_unlikely (n < 0 || (*name_ok) (bp) == 0))
 	{
 	  ++had_error;
 	  continue;
 	}
       cp += n;				/* name */
 
-      if (__builtin_expect (cp + 10 > end_of_message, 0))
+      if (__glibc_unlikely (cp + 10 > end_of_message))
 	{
 	  ++had_error;
 	  continue;
@@ -748,7 +751,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
       cp += INT32SZ;			/* TTL */
       n = __ns_get16 (cp);
       cp += INT16SZ;			/* len */
-      if (__builtin_expect (class != C_IN, 0))
+      if (__glibc_unlikely (class != C_IN))
 	{
 	  /* XXX - debug? syslog? */
 	  cp += n;
@@ -764,7 +767,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  if (ap >= &host_data->aliases[MAX_NR_ALIASES - 1])
 	    continue;
 	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
-	  if (__builtin_expect (n < 0 || (*name_ok) (tbuf) == 0, 0))
+	  if (__glibc_unlikely (n < 0 || (*name_ok) (tbuf) == 0))
 	    {
 	      ++had_error;
 	      continue;
@@ -782,7 +785,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  linebuflen -= n;
 	  /* Get canonical name.  */
 	  n = strlen (tbuf) + 1;	/* For the \0.  */
-	  if (__builtin_expect (n > linebuflen, 0))
+	  if (__glibc_unlikely (n > linebuflen))
 	    goto too_small;
 	  if (__builtin_expect (n, 0) >= MAXHOSTNAMELEN)
 	    {
@@ -797,8 +800,12 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 
       if (qtype == T_PTR && type == T_CNAME)
 	{
+	  /* A CNAME could also have a TTL entry.  */
+	  if (ttlp != NULL && ttl < *ttlp)
+	      *ttlp = ttl;
+
 	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
-	  if (__builtin_expect (n < 0 || res_dnok (tbuf) == 0, 0))
+	  if (__glibc_unlikely (n < 0 || res_dnok (tbuf) == 0))
 	    {
 	      ++had_error;
 	      continue;
@@ -806,7 +813,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  cp += n;
 	  /* Get canonical name.  */
 	  n = strlen (tbuf) + 1;   /* For the \0.  */
-	  if (__builtin_expect (n > linebuflen, 0))
+	  if (__glibc_unlikely (n > linebuflen))
 	    goto too_small;
 	  if (__builtin_expect (n, 0) >= MAXHOSTNAMELEN)
 	    {
@@ -818,26 +825,19 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  linebuflen -= n;
 	  continue;
 	}
-      if (__builtin_expect (type == T_SIG, 0)
-	  || __builtin_expect (type == T_KEY, 0)
-	  || __builtin_expect (type == T_NXT, 0))
-	{
-	  /* We don't support DNSSEC yet.  For now, ignore the record
-	     and send a low priority message to syslog.  */
-	  syslog (LOG_DEBUG | LOG_AUTH,
-	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
-		  qname, p_class (C_IN), p_type(qtype), p_type (type));
-	  cp += n;
-	  continue;
-	}
 
       if (type == T_A && qtype == T_AAAA && map)
 	have_to_map = 1;
-      else if (__builtin_expect (type != qtype, 0))
+      else if (__glibc_unlikely (type != qtype))
 	{
-	  syslog (LOG_NOTICE | LOG_AUTH,
-	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
-		  qname, p_class (C_IN), p_type (qtype), p_type (type));
+	  /* Log a low priority message if we get an unexpected record, but
+	     skip it if we are using DNSSEC since it uses many different types
+	     in responses that do not match QTYPE.  */
+	  if ((_res.options & RES_USE_DNSSEC) == 0)
+	    syslog (LOG_NOTICE | LOG_AUTH,
+		    "gethostby*.getanswer: asked for \"%s %s %s\", "
+		    "got type \"%s\"",
+		    qname, p_class (C_IN), p_type (qtype), p_type (type));
 	  cp += n;
 	  continue;			/* XXX - had_error++ ? */
 	}
@@ -845,7 +845,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
       switch (type)
 	{
 	case T_PTR:
-	  if (__builtin_expect (strcasecmp (tname, bp) != 0, 0))
+	  if (__glibc_unlikely (strcasecmp (tname, bp) != 0))
 	    {
 	      syslog (LOG_NOTICE | LOG_AUTH, AskedForGot, qname, bp);
 	      cp += n;
@@ -862,37 +862,20 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	      n = -1;
 	    }
 
-	  if (__builtin_expect (n < 0 || res_hnok (bp) == 0, 0))
+	  if (__glibc_unlikely (n < 0 || res_hnok (bp) == 0))
 	    {
 	      ++had_error;
 	      break;
 	    }
-#if MULTI_PTRS_ARE_ALIASES
-	  cp += n;
-	  if (haveanswer == 0)
-	    result->h_name = bp;
-	  else if (ap < &host_data->aliases[MAXALIASES-1])
-	    *ap++ = bp;
-	  else
-	    n = -1;
-	  if (n != -1)
-	    {
-	      n = strlen (bp) + 1;	/* for the \0 */
-	      if (__builtin_expect (n, 0) >= MAXHOSTNAMELEN)
-		{
-		  ++had_error;
-		  break;
-		}
-	      bp += n;
-	      linebuflen -= n;
-	    }
-	  break;
-#else
+	  if (ttlp != NULL && ttl < *ttlp)
+	      *ttlp = ttl;
+	  /* bind would put multiple PTR records as aliases, but we don't do
+	     that.  */
 	  result->h_name = bp;
 	  if (have_to_map)
 	    {
 	      n = strlen (bp) + 1;	/* for the \0 */
-	      if (__builtin_expect (n >= MAXHOSTNAMELEN, 0))
+	      if (__glibc_unlikely (n >= MAXHOSTNAMELEN))
 		{
 		  ++had_error;
 		  break;
@@ -904,7 +887,6 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	    }
 	  *h_errnop = NETDB_SUCCESS;
 	  return NSS_STATUS_SUCCESS;
-#endif
 	case T_A:
 	case T_AAAA:
 	  if (__builtin_expect (strcasecmp (result->h_name, bp), 0) != 0)
@@ -938,7 +920,7 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  linebuflen -= sizeof (align) - ((u_long) bp % sizeof (align));
 	  bp += sizeof (align) - ((u_long) bp % sizeof (align));
 
-	  if (__builtin_expect (n > linebuflen, 0))
+	  if (__glibc_unlikely (n > linebuflen))
 	    goto too_small;
 	  bp = __mempcpy (*hap++ = bp, cp, n);
 	  cp += n;
@@ -1009,7 +991,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
   int qdcount = ntohs (hp->qdcount);
   const u_char *cp = answer->buf + HFIXEDSZ;
   const u_char *end_of_message = answer->buf + anslen;
-  if (__builtin_expect (qdcount != 1, 0))
+  if (__glibc_unlikely (qdcount != 1))
     {
       *h_errnop = NO_RECOVERY;
       return NSS_STATUS_UNAVAIL;
@@ -1063,7 +1045,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
 
 	  n = -1;
 	}
-      if (__builtin_expect (n < 0 || res_hnok (buffer) == 0, 0))
+      if (__glibc_unlikely (n < 0 || res_hnok (buffer) == 0))
 	{
 	  ++had_error;
 	  continue;
@@ -1077,7 +1059,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
 
       cp += n;				/* name */
 
-      if (__builtin_expect (cp + 10 > end_of_message, 0))
+      if (__glibc_unlikely (cp + 10 > end_of_message))
 	{
 	  ++had_error;
 	  continue;
@@ -1107,7 +1089,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
 	      *ttlp = ttl;
 
 	  n = dn_expand (answer->buf, end_of_message, cp, tbuf, sizeof tbuf);
-	  if (__builtin_expect (n < 0 || res_hnok (tbuf) == 0, 0))
+	  if (__glibc_unlikely (n < 0 || res_hnok (tbuf) == 0))
 	    {
 	      ++had_error;
 	      continue;
@@ -1124,9 +1106,9 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
 		}
 
 	      n = strlen (tbuf) + 1;
-	      if (__builtin_expect (n > buflen, 0))
+	      if (__glibc_unlikely (n > buflen))
 		goto too_small;
-	      if (__builtin_expect (n >= MAXHOSTNAMELEN, 0))
+	      if (__glibc_unlikely (n >= MAXHOSTNAMELEN))
 		{
 		  ++had_error;
 		  continue;
@@ -1143,7 +1125,7 @@ gaih_getanswer_slice (const querybuf *answer, int anslen, const char *qname,
       // We should not see any types other than those explicitly listed
       // below.  Some types sent by server seem missing, though.  Just
       // collect the data for now.
-      if (__builtin_expect (type != T_A && type != T_AAAA, 0))
+      if (__glibc_unlikely (type != T_A && type != T_AAAA))
 #else
       if (__builtin_expect (type == T_SIG, 0)
 	  || __builtin_expect (type == T_KEY, 0)
diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
index 8e80a6010e..00f4490c5d 100644
--- a/resolv/nss_dns/dns-network.c
+++ b/resolv/nss_dns/dns-network.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+/* Copyright (C) 1996-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
@@ -129,7 +129,7 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result,
   net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
 
   anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
-			       1024, &net_buffer.ptr, NULL, NULL, NULL);
+			       1024, &net_buffer.ptr, NULL, NULL, NULL, NULL);
   if (anslen < 0)
     {
       /* Nothing found.  */
@@ -205,7 +205,7 @@ _nss_dns_getnetbyaddr_r (uint32_t net, int type, struct netent *result,
   net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
 
   anslen = __libc_res_nquery (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
-			      1024, &net_buffer.ptr, NULL, NULL, NULL);
+			      1024, &net_buffer.ptr, NULL, NULL, NULL, NULL);
   if (anslen < 0)
     {
       /* Nothing found.  */
@@ -268,7 +268,7 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
   uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct net_data);
   buffer += pad;
 
-  if (__builtin_expect (buflen < sizeof (*net_data) + pad, 0))
+  if (__glibc_unlikely (buflen < sizeof (*net_data) + pad))
     {
       /* The buffer is too small.  */
     too_small:
@@ -398,8 +398,8 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result,
 
 	case BYNAME:
 	  {
-	    char **ap = result->n_aliases++;
-	    while (*ap != NULL)
+	    char **ap;
+	    for (ap = result->n_aliases; *ap != NULL; ++ap)
 	      {
 		/* Check each alias name for being of the forms:
 		   4.3.2.1.in-addr.arpa		= net 1.2.3.4
diff --git a/resolv/res-state.c b/resolv/res-state.c
index 440940312e..d6775532b7 100644
--- a/resolv/res-state.c
+++ b/resolv/res-state.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+/* Copyright (C) 1996-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/resolv/res_hconf.c b/resolv/res_hconf.c
index b4c86227f8..0d4f3f45bc 100644
--- a/resolv/res_hconf.c
+++ b/resolv/res_hconf.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993-2014 Free Software Foundation, Inc.
+/* Copyright (C) 1993-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by David Mosberger (davidm@azstarnet.com).
 
@@ -46,6 +46,10 @@
 #include "res_hconf.h"
 #include <wchar.h>
 
+#if IS_IN (libc)
+# define fgets_unlocked __fgets_unlocked
+#endif
+
 #define _PATH_HOSTCONF	"/etc/host.conf"
 
 /* Environment vars that all user to override default behavior:  */
@@ -358,7 +362,7 @@ _res_hconf_init (void)
 }
 
 
-#ifndef NOT_IN_libc
+#if IS_IN (libc)
 # if defined SIOCGIFCONF && defined SIOCGIFNETMASK
 /* List of known interfaces.  */
 libc_freeres_ptr (
@@ -417,7 +421,7 @@ _res_hconf_reorder_addrs (struct hostent *hp)
       /* Get lock.  */
       __libc_lock_lock (lock);
 
-      /* Recheck, somebody else might have done the work by done.  */
+      /* Recheck, somebody else might have done the work by now.  */
       if (num_ifs <= 0)
 	{
 	  int new_num_ifs = 0;
@@ -435,18 +439,24 @@ _res_hconf_reorder_addrs (struct hostent *hp)
 	  for (cur_ifr = ifr, i = 0; i < num;
 	       cur_ifr = __if_nextreq (cur_ifr), ++i)
 	    {
+	      union
+	      {
+		struct sockaddr sa;
+		struct sockaddr_in sin;
+	      } ss;
+
 	      if (cur_ifr->ifr_addr.sa_family != AF_INET)
 		continue;
 
 	      ifaddrs[new_num_ifs].addrtype = AF_INET;
-	      ifaddrs[new_num_ifs].u.ipv4.addr =
-		((struct sockaddr_in *) &cur_ifr->ifr_addr)->sin_addr.s_addr;
+	      ss.sa = cur_ifr->ifr_addr;
+	      ifaddrs[new_num_ifs].u.ipv4.addr = ss.sin.sin_addr.s_addr;
 
 	      if (__ioctl (sd, SIOCGIFNETMASK, cur_ifr) < 0)
 		continue;
 
-	      ifaddrs[new_num_ifs].u.ipv4.mask =
-		((struct sockaddr_in *) &cur_ifr->ifr_netmask)->sin_addr.s_addr;
+	      ss.sa = cur_ifr->ifr_netmask;
+	      ifaddrs[new_num_ifs].u.ipv4.mask = ss.sin.sin_addr.s_addr;
 
 	      /* Now we're committed to this entry.  */
 	      ++new_num_ifs;
@@ -463,10 +473,10 @@ _res_hconf_reorder_addrs (struct hostent *hp)
 	  errno = save;
 
 	  num_ifs = new_num_ifs;
-
-	  __libc_lock_unlock (lock);
 	}
 
+      __libc_lock_unlock (lock);
+
       __close (sd);
     }
 
diff --git a/resolv/res_hconf.h b/resolv/res_hconf.h
index 1e0c2d9a22..42cef79965 100644
--- a/resolv/res_hconf.h
+++ b/resolv/res_hconf.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1993-2014 Free Software Foundation, Inc.
+/* Copyright (C) 1993-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by David Mosberger (davidm@azstarnet.com).
 
diff --git a/resolv/res_init.c b/resolv/res_init.c
index 5e1a747a4a..66561ffac2 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -153,10 +153,8 @@ __res_vinit(res_state statp, int preinit) {
 	char *cp, **pp;
 	int n;
 	char buf[BUFSIZ];
-	int nserv = 0;    /* number of nameserver records read from file */
-#ifdef _LIBC
-	int nservall = 0; /* number of NS records read, nserv IPv4 only */
-#endif
+	int nserv = 0;    /* number of nameservers read from file */
+	int have_serv6 = 0;
 	int haveenv = 0;
 	int havesearch = 0;
 #ifdef RESOLVSORT
@@ -184,15 +182,9 @@ __res_vinit(res_state statp, int preinit) {
 	statp->_flags = 0;
 	statp->qhook = NULL;
 	statp->rhook = NULL;
-	statp->_u._ext.nsinit = 0;
 	statp->_u._ext.nscount = 0;
-#ifdef _LIBC
-	statp->_u._ext.nscount6 = 0;
-	for (n = 0; n < MAXNS; n++) {
-		statp->_u._ext.nsaddrs[n] = NULL;
-		statp->_u._ext.nsmap[n] = MAXNS;
-	}
-#endif
+	for (n = 0; n < MAXNS; n++)
+	    statp->_u._ext.nsaddrs[n] = NULL;
 
 	/* Allow user to override the local domain definition */
 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
@@ -238,7 +230,7 @@ __res_vinit(res_state statp, int preinit) {
 	    /* No threads use this stream.  */
 	    __fsetlocking (fp, FSETLOCKING_BYCALLER);
 	    /* read the config file */
-	    while (fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
+	    while (__fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
 		/* skip comments */
 		if (*buf == ';' || *buf == '#')
 			continue;
@@ -296,11 +288,7 @@ __res_vinit(res_state statp, int preinit) {
 		    continue;
 		}
 		/* read nameservers to query */
-#ifdef _LIBC
-		if (MATCH(buf, "nameserver") && nservall < MAXNS) {
-#else
 		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
-#endif
 		    struct in_addr a;
 
 		    cp = buf + sizeof("nameserver") - 1;
@@ -308,13 +296,12 @@ __res_vinit(res_state statp, int preinit) {
 			cp++;
 		    if ((*cp != '\0') && (*cp != '\n')
 			&& __inet_aton(cp, &a)) {
-			statp->nsaddr_list[nservall].sin_addr = a;
-			statp->nsaddr_list[nservall].sin_family = AF_INET;
-			statp->nsaddr_list[nservall].sin_port =
+			statp->nsaddr_list[nserv].sin_addr = a;
+			statp->nsaddr_list[nserv].sin_family = AF_INET;
+			statp->nsaddr_list[nserv].sin_port =
 				htons(NAMESERVER_PORT);
 			nserv++;
 #ifdef _LIBC
-			nservall++;
 		    } else {
 			struct in6_addr a6;
 			char *el;
@@ -324,7 +311,7 @@ __res_vinit(res_state statp, int preinit) {
 			if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
 			    *el = '\0';
 			if ((*cp != '\0') &&
-			    (inet_pton(AF_INET6, cp, &a6) > 0)) {
+			    (__inet_pton(AF_INET6, cp, &a6) > 0)) {
 			    struct sockaddr_in6 *sa6;
 
 			    sa6 = malloc(sizeof(*sa6));
@@ -334,14 +321,14 @@ __res_vinit(res_state statp, int preinit) {
 				sa6->sin6_flowinfo = 0;
 				sa6->sin6_addr = a6;
 
-				if (__builtin_expect (el == NULL, 1))
+				if (__glibc_likely (el == NULL))
 				    sa6->sin6_scope_id = 0;
 				else {
 				    int try_numericscope = 1;
 				    if (IN6_IS_ADDR_LINKLOCAL (&a6)
 					|| IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
 					sa6->sin6_scope_id
-					  = if_nametoindex (el + 1);
+					  = __if_nametoindex (el + 1);
 					if (sa6->sin6_scope_id != 0)
 					    try_numericscope = 0;
 				    }
@@ -356,10 +343,11 @@ __res_vinit(res_state statp, int preinit) {
 				    }
 				}
 
-				statp->_u._ext.nsaddrs[nservall] = sa6;
-				statp->_u._ext.nssocks[nservall] = -1;
-				statp->_u._ext.nsmap[nservall] = MAXNS + 1;
-				nservall++;
+				statp->nsaddr_list[nserv].sin_family = 0;
+				statp->_u._ext.nsaddrs[nserv] = sa6;
+				statp->_u._ext.nssocks[nserv] = -1;
+				have_serv6 = 1;
+				nserv++;
 			    }
 			}
 #endif
@@ -414,10 +402,9 @@ __res_vinit(res_state statp, int preinit) {
 		    continue;
 		}
 	    }
-	    statp->nscount = nservall;
+	    statp->nscount = nserv;
 #ifdef _LIBC
-	    if (nservall - nserv > 0) {
-		statp->_u._ext.nscount6 = nservall - nserv;
+	    if (have_serv6) {
 		/* We try IPv6 servers again.  */
 		statp->ipv6_unavail = false;
 	    }
@@ -428,7 +415,7 @@ __res_vinit(res_state statp, int preinit) {
 	    (void) fclose(fp);
 	}
 	if (__builtin_expect(statp->nscount == 0, 0)) {
-	    statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
+	    statp->nsaddr.sin_addr = __inet_makeaddr(IN_LOOPBACKNET, 1);
 	    statp->nsaddr.sin_family = AF_INET;
 	    statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
 	    statp->nscount = 1;
@@ -606,11 +593,7 @@ __res_iclose(res_state statp, bool free_addr) {
 		statp->_vcsock = -1;
 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
 	}
-#ifdef _LIBC
-	for (ns = 0; ns < MAXNS; ns++)
-#else
 	for (ns = 0; ns < statp->_u._ext.nscount; ns++)
-#endif
 		if (statp->_u._ext.nsaddrs[ns]) {
 			if (statp->_u._ext.nssocks[ns] != -1) {
 				close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
@@ -621,7 +604,6 @@ __res_iclose(res_state statp, bool free_addr) {
 				statp->_u._ext.nsaddrs[ns] = NULL;
 			}
 		}
-	statp->_u._ext.nsinit = 0;
 }
 libc_hidden_def (__res_iclose)
 
diff --git a/resolv/res_mkquery.c b/resolv/res_mkquery.c
index 6170763fa3..1635e6a035 100644
--- a/resolv/res_mkquery.c
+++ b/resolv/res_mkquery.c
@@ -180,7 +180,7 @@ res_nmkquery(res_state statp,
 		n = ns_name_compress((char *)data, cp, buflen,
 				     (const u_char **) dnptrs,
 				     (const u_char **) lastdnptr);
-		if (__builtin_expect (n < 0, 0))
+		if (__glibc_unlikely (n < 0))
 			return (-1);
 		cp += n;
 		buflen -= n;
@@ -195,7 +195,7 @@ res_nmkquery(res_state statp,
 		/*
 		 * Initialize answer section
 		 */
-		if (__builtin_expect (buflen < 1 + RRFIXEDSZ + datalen, 0))
+		if (__glibc_unlikely (buflen < 1 + RRFIXEDSZ + datalen))
 			return (-1);
 		*cp++ = '\0';	/* no domain name */
 		NS_PUT16 (type, cp);
diff --git a/resolv/res_query.c b/resolv/res_query.c
index 1325f9772d..4a9b3b3f27 100644
--- a/resolv/res_query.c
+++ b/resolv/res_query.c
@@ -98,7 +98,7 @@ static int
 __libc_res_nquerydomain(res_state statp, const char *name, const char *domain,
 			int class, int type, u_char *answer, int anslen,
 			u_char **answerp, u_char **answerp2, int *nanswerp2,
-			int *resplen2);
+			int *resplen2, int *answerp2_malloced);
 
 /*
  * Formulate a normal query, send, and await answer.
@@ -119,7 +119,8 @@ __libc_res_nquery(res_state statp,
 		  u_char **answerp,	/* if buffer needs to be enlarged */
 		  u_char **answerp2,
 		  int *nanswerp2,
-		  int *resplen2)
+		  int *resplen2,
+		  int *answerp2_malloced)
 {
 	HEADER *hp = (HEADER *) answer;
 	HEADER *hp2;
@@ -202,7 +203,7 @@ __libc_res_nquery(res_state statp,
 			goto again;
 		}
 	}
-	if (__builtin_expect (n <= 0, 0)) {
+	if (__glibc_unlikely (n <= 0))       {
 		/* If the query choked with EDNS0, retry without EDNS0.  */
 		if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0
 		    && ((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
@@ -224,7 +225,8 @@ __libc_res_nquery(res_state statp,
 	}
 	assert (answerp == NULL || (void *) *answerp == (void *) answer);
 	n = __libc_res_nsend(statp, query1, nquery1, query2, nquery2, answer,
-			     anslen, answerp, answerp2, nanswerp2, resplen2);
+			     anslen, answerp, answerp2, nanswerp2, resplen2,
+			     answerp2_malloced);
 	if (use_malloc)
 		free (buf);
 	if (n < 0) {
@@ -316,7 +318,7 @@ res_nquery(res_state statp,
 	   int anslen)		/* size of answer buffer */
 {
 	return __libc_res_nquery(statp, name, class, type, answer, anslen,
-				 NULL, NULL, NULL, NULL);
+				 NULL, NULL, NULL, NULL, NULL);
 }
 libresolv_hidden_def (res_nquery)
 
@@ -335,7 +337,8 @@ __libc_res_nsearch(res_state statp,
 		   u_char **answerp,
 		   u_char **answerp2,
 		   int *nanswerp2,
-		   int *resplen2)
+		   int *resplen2,
+		   int *answerp2_malloced)
 {
 	const char *cp, * const *domain;
 	HEADER *hp = (HEADER *) answer;
@@ -360,7 +363,7 @@ __libc_res_nsearch(res_state statp,
 	if (!dots && (cp = res_hostalias(statp, name, tmp, sizeof tmp))!= NULL)
 		return (__libc_res_nquery(statp, cp, class, type, answer,
 					  anslen, answerp, answerp2,
-					  nanswerp2, resplen2));
+					  nanswerp2, resplen2, answerp2_malloced));
 
 #ifdef DEBUG
 	if (statp->options & RES_DEBUG)
@@ -377,8 +380,11 @@ __libc_res_nsearch(res_state statp,
 	if (dots >= statp->ndots || trailing_dot) {
 		ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
 					      answer, anslen, answerp,
-					      answerp2, nanswerp2, resplen2);
-		if (ret > 0 || trailing_dot)
+					      answerp2, nanswerp2, resplen2,
+					      answerp2_malloced);
+		if (ret > 0 || trailing_dot
+		    /* If the second response is valid then we use that.  */
+		    || (ret == 0 && resplen2 != NULL && *resplen2 > 0))
 			return (ret);
 		saved_herrno = h_errno;
 		tried_as_is++;
@@ -386,11 +392,11 @@ __libc_res_nsearch(res_state statp,
 			answer = *answerp;
 			anslen = MAXPACKET;
 		}
-		if (answerp2
-		    && (*answerp2 < answer || *answerp2 >= answer + anslen))
+		if (answerp2 && *answerp2_malloced)
 		  {
 		    free (*answerp2);
 		    *answerp2 = NULL;
+		    *answerp2_malloced = 0;
 		  }
 	}
 
@@ -407,30 +413,41 @@ __libc_res_nsearch(res_state statp,
 		for (domain = (const char * const *)statp->dnsrch;
 		     *domain && !done;
 		     domain++) {
+			const char *dname = domain[0];
 			searched = 1;
 
-			if (domain[0][0] == '\0' ||
-			    (domain[0][0] == '.' && domain[0][1] == '\0'))
+			/* __libc_res_nquerydoman concatenates name
+			   with dname with a "." in between.  If we
+			   pass it in dname the "." we got from the
+			   configured default search path, we'll end
+			   up with "name..", which won't resolve.
+			   OTOH, passing it "" will result in "name.",
+			   which has the intended effect for both
+			   possible representations of the root
+			   domain.  */
+			if (dname[0] == '.')
+				dname++;
+			if (dname[0] == '\0')
 				root_on_list++;
 
-			ret = __libc_res_nquerydomain(statp, name, *domain,
+			ret = __libc_res_nquerydomain(statp, name, dname,
 						      class, type,
 						      answer, anslen, answerp,
 						      answerp2, nanswerp2,
-						      resplen2);
-			if (ret > 0)
+						      resplen2, answerp2_malloced);
+			if (ret > 0 || (ret == 0 && resplen2 != NULL
+					&& *resplen2 > 0))
 				return (ret);
 
 			if (answerp && *answerp != answer) {
 				answer = *answerp;
 				anslen = MAXPACKET;
 			}
-			if (answerp2
-			    && (*answerp2 < answer
-				|| *answerp2 >= answer + anslen))
+			if (answerp2 && *answerp2_malloced)
 			  {
 			    free (*answerp2);
 			    *answerp2 = NULL;
+			    *answerp2_malloced = 0;
 			  }
 
 			/*
@@ -479,15 +496,17 @@ __libc_res_nsearch(res_state statp,
 	}
 
 	/*
-	 * f the query has not already been tried as is then try it
+	 * If the query has not already been tried as is then try it
 	 * unless RES_NOTLDQUERY is set and there were no dots.
 	 */
 	if ((dots || !searched || (statp->options & RES_NOTLDQUERY) == 0)
 	    && !(tried_as_is || root_on_list)) {
 		ret = __libc_res_nquerydomain(statp, name, NULL, class, type,
 					      answer, anslen, answerp,
-					      answerp2, nanswerp2, resplen2);
-		if (ret > 0)
+					      answerp2, nanswerp2, resplen2,
+					      answerp2_malloced);
+		if (ret > 0 || (ret == 0 && resplen2 != NULL
+				&& *resplen2 > 0))
 			return (ret);
 	}
 
@@ -498,10 +517,11 @@ __libc_res_nsearch(res_state statp,
 	 * else send back meaningless H_ERRNO, that being the one from
 	 * the last DNSRCH we did.
 	 */
-	if (answerp2 && (*answerp2 < answer || *answerp2 >= answer + anslen))
+	if (answerp2 && *answerp2_malloced)
 	  {
 	    free (*answerp2);
 	    *answerp2 = NULL;
+	    *answerp2_malloced = 0;
 	  }
 	if (saved_herrno != -1)
 		RES_SET_H_ERRNO(statp, saved_herrno);
@@ -521,13 +541,12 @@ res_nsearch(res_state statp,
 	    int anslen)		/* size of answer */
 {
 	return __libc_res_nsearch(statp, name, class, type, answer,
-				  anslen, NULL, NULL, NULL, NULL);
+				  anslen, NULL, NULL, NULL, NULL, NULL);
 }
 libresolv_hidden_def (res_nsearch)
 
 /*
- * Perform a call on res_query on the concatenation of name and domain,
- * removing a trailing dot from name if domain is NULL.
+ * Perform a call on res_query on the concatenation of name and domain.
  */
 static int
 __libc_res_nquerydomain(res_state statp,
@@ -539,7 +558,8 @@ __libc_res_nquerydomain(res_state statp,
 			u_char **answerp,
 			u_char **answerp2,
 			int *nanswerp2,
-			int *resplen2)
+			int *resplen2,
+			int *answerp2_malloced)
 {
 	char nbuf[MAXDNAME];
 	const char *longname = nbuf;
@@ -551,10 +571,6 @@ __libc_res_nquerydomain(res_state statp,
 		       name, domain?domain:"<Nil>", class, type);
 #endif
 	if (domain == NULL) {
-		/*
-		 * Check for trailing '.';
-		 * copy without '.' if present.
-		 */
 		n = strlen(name);
 
 		/* Decrement N prior to checking it against MAXDNAME
@@ -565,11 +581,7 @@ __libc_res_nquerydomain(res_state statp,
 			RES_SET_H_ERRNO(statp, NO_RECOVERY);
 			return (-1);
 		}
-		if (name[n] == '.') {
-			strncpy(nbuf, name, n);
-			nbuf[n] = '\0';
-		} else
-			longname = name;
+		longname = name;
 	} else {
 		n = strlen(name);
 		d = strlen(domain);
@@ -581,7 +593,7 @@ __libc_res_nquerydomain(res_state statp,
 	}
 	return (__libc_res_nquery(statp, longname, class, type, answer,
 				  anslen, answerp, answerp2, nanswerp2,
-				  resplen2));
+				  resplen2, answerp2_malloced));
 }
 
 int
@@ -593,7 +605,8 @@ res_nquerydomain(res_state statp,
 	    int anslen)		/* size of answer */
 {
 	return __libc_res_nquerydomain(statp, name, domain, class, type,
-				       answer, anslen, NULL, NULL, NULL, NULL);
+				       answer, anslen, NULL, NULL, NULL, NULL,
+				       NULL);
 }
 libresolv_hidden_def (res_nquerydomain)
 
diff --git a/resolv/res_send.c b/resolv/res_send.c
index 7f2e85f324..5e53cc2df6 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -96,6 +96,7 @@ static const char rcsid[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixi
 #include <string.h>
 #include <unistd.h>
 #include <kernel-features.h>
+#include <libc-internal.h>
 
 #if PACKETSZ > 65536
 #define MAXPACKET       PACKETSZ
@@ -183,15 +184,16 @@ evNowTime(struct timespec *res) {
 
 /* Forward. */
 
+static struct sockaddr *get_nsaddr (res_state, int);
 static int		send_vc(res_state, const u_char *, int,
 				const u_char *, int,
 				u_char **, int *, int *, int, u_char **,
-				u_char **, int *, int *);
+				u_char **, int *, int *, int *);
 static int		send_dg(res_state, const u_char *, int,
 				const u_char *, int,
 				u_char **, int *, int *, int,
 				int *, int *, u_char **,
-				u_char **, int *, int *);
+				u_char **, int *, int *, int *);
 #ifdef DEBUG
 static void		Aerror(const res_state, FILE *, const char *, int,
 			       const struct sockaddr *);
@@ -220,20 +222,21 @@ res_ourserver_p(const res_state statp, const struct sockaddr_in6 *inp)
 	    in_port_t port = in4p->sin_port;
 	    in_addr_t addr = in4p->sin_addr.s_addr;
 
-	    for (ns = 0;  ns < MAXNS;  ns++) {
+	    for (ns = 0;  ns < statp->nscount;  ns++) {
 		const struct sockaddr_in *srv =
-		    (struct sockaddr_in *)EXT(statp).nsaddrs[ns];
+		    (struct sockaddr_in *) get_nsaddr (statp, ns);
 
-		if ((srv != NULL) && (srv->sin_family == AF_INET) &&
+		if ((srv->sin_family == AF_INET) &&
 		    (srv->sin_port == port) &&
 		    (srv->sin_addr.s_addr == INADDR_ANY ||
 		     srv->sin_addr.s_addr == addr))
 		    return (1);
 	    }
 	} else if (inp->sin6_family == AF_INET6) {
-	    for (ns = 0;  ns < MAXNS;  ns++) {
-		const struct sockaddr_in6 *srv = EXT(statp).nsaddrs[ns];
-		if ((srv != NULL) && (srv->sin6_family == AF_INET6) &&
+	    for (ns = 0;  ns < statp->nscount;  ns++) {
+		const struct sockaddr_in6 *srv
+		  = (struct sockaddr_in6 *) get_nsaddr (statp, ns);
+		if ((srv->sin6_family == AF_INET6) &&
 		    (srv->sin6_port == inp->sin6_port) &&
 		    !(memcmp(&srv->sin6_addr, &in6addr_any,
 			     sizeof (struct in6_addr)) &&
@@ -343,7 +346,7 @@ int
 __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 		 const u_char *buf2, int buflen2,
 		 u_char *ans, int anssiz, u_char **ansp, u_char **ansp2,
-		 int *nansp2, int *resplen2)
+		 int *nansp2, int *resplen2, int *ansp2_malloced)
 {
   int gotsomewhere, terrno, try, v_circuit, resplen, ns, n;
 
@@ -358,7 +361,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 	}
 
 #ifdef USE_HOOKS
-	if (__builtin_expect (statp->qhook || statp->rhook, 0)) {
+	if (__glibc_unlikely (statp->qhook || statp->rhook))       {
 		if (anssiz < MAXPACKET && ansp) {
 			u_char *buf = malloc (MAXPACKET);
 			if (buf == NULL)
@@ -383,74 +386,48 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 	 * If the ns_addr_list in the resolver context has changed, then
 	 * invalidate our cached copy and the associated timing data.
 	 */
-	if (EXT(statp).nsinit) {
+	if (EXT(statp).nscount != 0) {
 		int needclose = 0;
 
 		if (EXT(statp).nscount != statp->nscount)
 			needclose++;
 		else
-			for (ns = 0; ns < MAXNS; ns++) {
-				unsigned int map = EXT(statp).nsmap[ns];
-				if (map < MAXNS
+			for (ns = 0; ns < statp->nscount; ns++) {
+				if (statp->nsaddr_list[ns].sin_family != 0
 				    && !sock_eq((struct sockaddr_in6 *)
-						&statp->nsaddr_list[map],
+						&statp->nsaddr_list[ns],
 						EXT(statp).nsaddrs[ns]))
 				{
 					needclose++;
 					break;
 				}
 			}
-		if (needclose)
+		if (needclose) {
 			__res_iclose(statp, false);
+			EXT(statp).nscount = 0;
+		}
 	}
 
 	/*
 	 * Maybe initialize our private copy of the ns_addr_list.
 	 */
-	if (EXT(statp).nsinit == 0) {
-		unsigned char map[MAXNS];
-
-		memset (map, MAXNS, sizeof (map));
-		for (n = 0; n < MAXNS; n++) {
-			ns = EXT(statp).nsmap[n];
-			if (ns < statp->nscount)
-				map[ns] = n;
-			else if (ns < MAXNS) {
-				free(EXT(statp).nsaddrs[n]);
-				EXT(statp).nsaddrs[n] = NULL;
-				EXT(statp).nsmap[n] = MAXNS;
-			}
-		}
-		n = statp->nscount;
-		if (statp->nscount > EXT(statp).nscount)
-			for (n = EXT(statp).nscount, ns = 0;
-			     n < statp->nscount; n++) {
-				while (ns < MAXNS
-				       && EXT(statp).nsmap[ns] != MAXNS)
-					ns++;
-				if (ns == MAXNS)
-					break;
-				EXT(statp).nsmap[ns] = n;
-				map[n] = ns++;
-			}
-		EXT(statp).nscount = n;
-		for (ns = 0; ns < EXT(statp).nscount; ns++) {
-			n = map[ns];
-			if (EXT(statp).nsaddrs[n] == NULL)
-				EXT(statp).nsaddrs[n] =
+	if (EXT(statp).nscount == 0) {
+		for (ns = 0; ns < statp->nscount; ns++) {
+			EXT(statp).nssocks[ns] = -1;
+			if (statp->nsaddr_list[ns].sin_family == 0)
+				continue;
+			if (EXT(statp).nsaddrs[ns] == NULL)
+				EXT(statp).nsaddrs[ns] =
 				    malloc(sizeof (struct sockaddr_in6));
-			if (EXT(statp).nsaddrs[n] != NULL) {
-				memset (mempcpy(EXT(statp).nsaddrs[n],
+			if (EXT(statp).nsaddrs[ns] != NULL)
+				memset (mempcpy(EXT(statp).nsaddrs[ns],
 						&statp->nsaddr_list[ns],
 						sizeof (struct sockaddr_in)),
 					'\0',
 					sizeof (struct sockaddr_in6)
 					- sizeof (struct sockaddr_in));
-				EXT(statp).nssocks[n] = -1;
-				n++;
-			}
 		}
-		EXT(statp).nsinit = 1;
+		EXT(statp).nscount = statp->nscount;
 	}
 
 	/*
@@ -459,47 +436,40 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 	 */
 	if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0) &&
 	    (statp->options & RES_BLAST) == 0) {
-		struct sockaddr_in6 *ina;
-		unsigned int map;
-
-		n = 0;
-		while (n < MAXNS && EXT(statp).nsmap[n] == MAXNS)
-			n++;
-		if (n < MAXNS) {
-			ina = EXT(statp).nsaddrs[n];
-			map = EXT(statp).nsmap[n];
-			for (;;) {
-				ns = n + 1;
-				while (ns < MAXNS
-				       && EXT(statp).nsmap[ns] == MAXNS)
-					ns++;
-				if (ns == MAXNS)
-					break;
-				EXT(statp).nsaddrs[n] = EXT(statp).nsaddrs[ns];
-				EXT(statp).nsmap[n] = EXT(statp).nsmap[ns];
-				n = ns;
-			}
-			EXT(statp).nsaddrs[n] = ina;
-			EXT(statp).nsmap[n] = map;
+		struct sockaddr_in ina;
+		struct sockaddr_in6 *inp;
+		int lastns = statp->nscount - 1;
+		int fd;
+
+		inp = EXT(statp).nsaddrs[0];
+		ina = statp->nsaddr_list[0];
+		fd = EXT(statp).nssocks[0];
+		for (ns = 0; ns < lastns; ns++) {
+		    EXT(statp).nsaddrs[ns] = EXT(statp).nsaddrs[ns + 1];
+		    statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
+		    EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
 		}
+		EXT(statp).nsaddrs[lastns] = inp;
+		statp->nsaddr_list[lastns] = ina;
+		EXT(statp).nssocks[lastns] = fd;
 	}
 
 	/*
 	 * Send request, RETRY times, or until successful.
 	 */
 	for (try = 0; try < statp->retry; try++) {
-	    for (ns = 0; ns < MAXNS; ns++)
+	    for (ns = 0; ns < statp->nscount; ns++)
 	    {
 #ifdef DEBUG
 		char tmpbuf[40];
 #endif
-		struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
+#if defined USE_HOOKS || defined DEBUG
+		struct sockaddr *nsap = get_nsaddr (statp, ns);
+#endif
 
-		if (nsap == NULL)
-			goto next_ns;
 	    same_ns:
 #ifdef USE_HOOKS
-		if (__builtin_expect (statp->qhook != NULL, 0)) {
+		if (__glibc_unlikely (statp->qhook != NULL))       {
 			int done = 0, loops = 0;
 
 			do {
@@ -535,18 +505,19 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 
 		Dprint(statp->options & RES_DEBUG,
 		       (stdout, ";; Querying server (# %d) address = %s\n",
-			ns + 1, inet_ntop(nsap->sin6_family,
-					  (nsap->sin6_family == AF_INET6
-					   ? &nsap->sin6_addr
+			ns + 1, inet_ntop(nsap->sa_family,
+					  (nsap->sa_family == AF_INET6
+					   ? &((struct sockaddr_in6 *) nsap)->sin6_addr
 					   : &((struct sockaddr_in *) nsap)->sin_addr),
 					  tmpbuf, sizeof (tmpbuf))));
 
-		if (__builtin_expect (v_circuit, 0)) {
+		if (__glibc_unlikely (v_circuit))       {
 			/* Use VC; at most one attempt per server. */
 			try = statp->retry;
 			n = send_vc(statp, buf, buflen, buf2, buflen2,
 				    &ans, &anssiz, &terrno,
-				    ns, ansp, ansp2, nansp2, resplen2);
+				    ns, ansp, ansp2, nansp2, resplen2,
+				    ansp2_malloced);
 			if (n < 0)
 				return (-1);
 			if (n == 0 && (buf2 == NULL || *resplen2 == 0))
@@ -556,7 +527,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 			n = send_dg(statp, buf, buflen, buf2, buflen2,
 				    &ans, &anssiz, &terrno,
 				    ns, &v_circuit, &gotsomewhere, ansp,
-				    ansp2, nansp2, resplen2);
+				    ansp2, nansp2, resplen2, ansp2_malloced);
 			if (n < 0)
 				return (-1);
 			if (n == 0 && (buf2 == NULL || *resplen2 == 0))
@@ -595,7 +566,7 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 			__res_iclose(statp, false);
 		}
 #ifdef USE_HOOKS
-		if (__builtin_expect (statp->rhook, 0)) {
+		if (__glibc_unlikely (statp->rhook))       {
 			int done = 0, loops = 0;
 
 			do {
@@ -646,18 +617,33 @@ res_nsend(res_state statp,
 	  const u_char *buf, int buflen, u_char *ans, int anssiz)
 {
   return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz,
-			  NULL, NULL, NULL, NULL);
+			  NULL, NULL, NULL, NULL, NULL);
 }
 libresolv_hidden_def (res_nsend)
 
 /* Private */
 
+static struct sockaddr *
+get_nsaddr (res_state statp, int n)
+{
+
+  if (statp->nsaddr_list[n].sin_family == 0 && EXT(statp).nsaddrs[n] != NULL)
+    /* EXT(statp).nsaddrs[n] holds an address that is larger than
+       struct sockaddr, and user code did not update
+       statp->nsaddr_list[n].  */
+    return (struct sockaddr *) EXT(statp).nsaddrs[n];
+  else
+    /* User code updated statp->nsaddr_list[n], or statp->nsaddr_list[n]
+       has the same content as EXT(statp).nsaddrs[n].  */
+    return (struct sockaddr *) (void *) &statp->nsaddr_list[n];
+}
+
 static int
 send_vc(res_state statp,
 	const u_char *buf, int buflen, const u_char *buf2, int buflen2,
 	u_char **ansp, int *anssizp,
 	int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2,
-	int *resplen2)
+	int *resplen2, int *ansp2_malloced)
 {
 	const HEADER *hp = (HEADER *) buf;
 	const HEADER *hp2 = (HEADER *) buf2;
@@ -666,8 +652,25 @@ send_vc(res_state statp,
 	// XXX REMOVE
 	// int anssiz = *anssizp;
 	HEADER *anhp = (HEADER *) ans;
-	struct sockaddr_in6 *nsap = EXT(statp).nsaddrs[ns];
-	int truncating, connreset, resplen, n;
+	struct sockaddr *nsap = get_nsaddr (statp, ns);
+	int truncating, connreset, n;
+	/* On some architectures compiler might emit a warning indicating
+	   'resplen' may be used uninitialized.  However if buf2 == NULL
+	   then this code won't be executed; if buf2 != NULL, then first
+	   time round the loop recvresp1 and recvresp2 will be 0 so this
+	   code won't be executed but "thisresplenp = &resplen;" followed
+	   by "*thisresplenp = rlen;" will be executed so that subsequent
+	   times round the loop resplen has been initialized.  So this is
+	   a false-positive.
+	 */
+#if __GNUC_PREREQ (4, 7)
+	DIAG_PUSH_NEEDS_COMMENT;
+	DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
+#endif
+	int resplen;
+#if __GNUC_PREREQ (4, 7)
+	DIAG_POP_NEEDS_COMMENT;
+#endif
 	struct iovec iov[4];
 	u_short len;
 	u_short len2;
@@ -686,8 +689,8 @@ send_vc(res_state statp,
 
 		if (getpeername(statp->_vcsock,
 				(struct sockaddr *)&peer, &size) < 0 ||
-		    !sock_eq(&peer, nsap)) {
-		  __res_iclose(statp, false);
+		    !sock_eq(&peer, (struct sockaddr_in6 *) nsap)) {
+			__res_iclose(statp, false);
 			statp->_flags &= ~RES_F_VC;
 		}
 	}
@@ -696,20 +699,19 @@ send_vc(res_state statp,
 		if (statp->_vcsock >= 0)
 		  __res_iclose(statp, false);
 
-		statp->_vcsock = socket(nsap->sin6_family, SOCK_STREAM, 0);
+		statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM, 0);
 		if (statp->_vcsock < 0) {
 			*terrno = errno;
 			Perror(statp, stderr, "socket(vc)", errno);
 			return (-1);
 		}
 		__set_errno (0);
-		if (connect(statp->_vcsock, (struct sockaddr *)nsap,
-			    nsap->sin6_family == AF_INET
+		if (connect(statp->_vcsock, nsap,
+			    nsap->sa_family == AF_INET
 			    ? sizeof (struct sockaddr_in)
 			    : sizeof (struct sockaddr_in6)) < 0) {
 			*terrno = errno;
-			Aerror(statp, stderr, "connect/vc", errno,
-			       (struct sockaddr *) nsap);
+			Aerror(statp, stderr, "connect/vc", errno, nsap);
 			__res_iclose(statp, false);
 			return (0);
 		}
@@ -786,7 +788,11 @@ send_vc(res_state statp,
 			/* No buffer allocated for the first
 			   reply.  We can try to use the rest
 			   of the user-provided buffer.  */
-#ifdef _STRING_ARCH_unaligned
+#if __GNUC_PREREQ (4, 7)
+			DIAG_PUSH_NEEDS_COMMENT;
+			DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
+#endif
+#if _STRING_ARCH_unaligned
 			*anssizp2 = orig_anssizp - resplen;
 			*ansp2 = *ansp + resplen;
 #else
@@ -796,6 +802,9 @@ send_vc(res_state statp,
 			*anssizp2 = orig_anssizp - aligned_resplen;
 			*ansp2 = *ansp + aligned_resplen;
 #endif
+#if __GNUC_PREREQ (4, 7)
+			DIAG_POP_NEEDS_COMMENT;
+#endif
 		} else {
 			/* The first reply did not fit into the
 			   user-provided buffer.  Maybe the second
@@ -814,7 +823,7 @@ send_vc(res_state statp,
 	if (rlen > *thisanssizp) {
 		/* Yes, we test ANSCP here.  If we have two buffers
 		   both will be allocatable.  */
-		if (__builtin_expect (anscp != NULL, 1)) {
+		if (__glibc_likely (anscp != NULL))       {
 			u_char *newp = malloc (MAXPACKET);
 			if (newp == NULL) {
 				*terrno = ENOMEM;
@@ -823,6 +832,8 @@ send_vc(res_state statp,
 			}
 			*thisanssizp = MAXPACKET;
 			*thisansp = newp;
+			if (thisansp == ansp2)
+			  *ansp2_malloced = 1;
 			anhp = (HEADER *) newp;
 			len = rlen;
 		} else {
@@ -835,7 +846,7 @@ send_vc(res_state statp,
 	} else
 		len = rlen;
 
-	if (__builtin_expect (len < HFIXEDSZ, 0)) {
+	if (__glibc_unlikely (len < HFIXEDSZ))       {
 		/*
 		 * Undersized message.
 		 */
@@ -851,13 +862,13 @@ send_vc(res_state statp,
 		cp += n;
 		len -= n;
 	}
-	if (__builtin_expect (n <= 0, 0)) {
+	if (__glibc_unlikely (n <= 0))       {
 		*terrno = errno;
 		Perror(statp, stderr, "read(vc)", errno);
 		__res_iclose(statp, false);
 		return (0);
 	}
-	if (__builtin_expect (truncating, 0)) {
+	if (__glibc_unlikely (truncating))       {
 		/*
 		 * Flush rest of answer so connection stays in synch.
 		 */
@@ -911,13 +922,12 @@ static int
 reopen (res_state statp, int *terrno, int ns)
 {
 	if (EXT(statp).nssocks[ns] == -1) {
-		struct sockaddr *nsap
-		  = (struct sockaddr *) EXT(statp).nsaddrs[ns];
+		struct sockaddr *nsap = get_nsaddr (statp, ns);
 		socklen_t slen;
 
 		/* only try IPv6 if IPv6 NS and if not failed before */
 		if (nsap->sa_family == AF_INET6 && !statp->ipv6_unavail) {
-			if (__builtin_expect (__have_o_nonblock >= 0, 1)) {
+			if (__glibc_likely (__have_o_nonblock >= 0))       {
 				EXT(statp).nssocks[ns] =
 				  socket(PF_INET6, SOCK_DGRAM|SOCK_NONBLOCK,
 					 0);
@@ -928,14 +938,14 @@ reopen (res_state statp, int *terrno, int ns)
 					     && errno == EINVAL ? -1 : 1);
 #endif
 			}
-			if (__builtin_expect (__have_o_nonblock < 0, 0))
+			if (__glibc_unlikely (__have_o_nonblock < 0))
 				EXT(statp).nssocks[ns] =
 				  socket(PF_INET6, SOCK_DGRAM, 0);
 			if (EXT(statp).nssocks[ns] < 0)
 			    statp->ipv6_unavail = errno == EAFNOSUPPORT;
 			slen = sizeof (struct sockaddr_in6);
 		} else if (nsap->sa_family == AF_INET) {
-			if (__builtin_expect (__have_o_nonblock >= 0, 1)) {
+			if (__glibc_likely (__have_o_nonblock >= 0))       {
 				EXT(statp).nssocks[ns]
 				  = socket(PF_INET, SOCK_DGRAM|SOCK_NONBLOCK,
 					   0);
@@ -946,7 +956,7 @@ reopen (res_state statp, int *terrno, int ns)
 					     && errno == EINVAL ? -1 : 1);
 #endif
 			}
-			if (__builtin_expect (__have_o_nonblock < 0, 0))
+			if (__glibc_unlikely (__have_o_nonblock < 0))
 				EXT(statp).nssocks[ns]
 				  = socket(PF_INET, SOCK_DGRAM, 0);
 			slen = sizeof (struct sockaddr_in);
@@ -973,7 +983,7 @@ reopen (res_state statp, int *terrno, int ns)
 			__res_iclose(statp, false);
 			return (0);
 		}
-		if (__builtin_expect (__have_o_nonblock < 0, 0)) {
+		if (__glibc_unlikely (__have_o_nonblock < 0))       {
 			/* Make socket non-blocking.  */
 			int fl = __fcntl (EXT(statp).nssocks[ns], F_GETFL);
 			if  (fl != -1)
@@ -992,7 +1002,7 @@ send_dg(res_state statp,
 	const u_char *buf, int buflen, const u_char *buf2, int buflen2,
 	u_char **ansp, int *anssizp,
 	int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp,
-	u_char **ansp2, int *anssizp2, int *resplen2)
+	u_char **ansp2, int *anssizp2, int *resplen2, int *ansp2_malloced)
 {
 	const HEADER *hp = (HEADER *) buf;
 	const HEADER *hp2 = (HEADER *) buf2;
@@ -1055,7 +1065,7 @@ send_dg(res_state statp,
 	n = 0;
 	if (nwritten == 0)
 	  n = __poll (pfd, 1, 0);
-	if (__builtin_expect (n == 0, 0)) {
+	if (__glibc_unlikely (n == 0))       {
 		n = __poll (pfd, 1, ptimeout);
 		need_recompute = 1;
 	}
@@ -1130,7 +1140,7 @@ send_dg(res_state statp,
 		    reqs[1].msg_hdr.msg_controllen = 0;
 
 		    int ndg = __sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL);
-		    if (__builtin_expect (ndg == 2, 1))
+		    if (__glibc_likely (ndg == 2))
 		      {
 			if (reqs[0].msg_len != buflen
 			    || reqs[1].msg_len != buflen2)
@@ -1146,7 +1156,7 @@ send_dg(res_state statp,
 		    else
 		      {
 #ifndef __ASSUME_SENDMMSG
-			if (__builtin_expect (have_sendmmsg == 0, 0))
+			if (__glibc_unlikely (have_sendmmsg == 0))
 			  {
 			    if (ndg < 0 && errno == ENOSYS)
 			      {
@@ -1202,7 +1212,7 @@ send_dg(res_state statp,
 				/* No buffer allocated for the first
 				   reply.  We can try to use the rest
 				   of the user-provided buffer.  */
-#ifdef _STRING_ARCH_unaligned
+#if _STRING_ARCH_unaligned
 				*anssizp2 = orig_anssizp - resplen;
 				*ansp2 = *ansp + resplen;
 #else
@@ -1238,6 +1248,8 @@ send_dg(res_state statp,
 			if (newp != NULL) {
 				*anssizp = MAXPACKET;
 				*thisansp = ans = newp;
+				if (thisansp == ansp2)
+				  *ansp2_malloced = 1;
 			}
 		}
 		HEADER *anhp = (HEADER *) *thisansp;
@@ -1246,7 +1258,7 @@ send_dg(res_state statp,
 		*thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp,
 					 *thisanssizp, 0,
 					(struct sockaddr *)&from, &fromlen);
-		if (__builtin_expect (*thisresplenp <= 0, 0)) {
+		if (__glibc_unlikely (*thisresplenp <= 0))       {
 			if (errno == EINTR || errno == EAGAIN) {
 				need_recompute = 1;
 				goto wait;
@@ -1255,7 +1267,7 @@ send_dg(res_state statp,
 			goto err_out;
 		}
 		*gotsomewhere = 1;
-		if (__builtin_expect (*thisresplenp < HFIXEDSZ, 0)) {
+		if (__glibc_unlikely (*thisresplenp < HFIXEDSZ))       {
 			/*
 			 * Undersized message.
 			 */
@@ -1346,6 +1358,7 @@ send_dg(res_state statp,
 				(*thisresplenp > *thisanssizp)
 				? *thisanssizp : *thisresplenp);
 
+		next_ns:
 			if (recvresp1 || (buf2 != NULL && recvresp2)) {
 			  *resplen2 = 0;
 			  return resplen;
@@ -1363,7 +1376,6 @@ send_dg(res_state statp,
 			    goto wait;
 			  }
 
-		next_ns:
 			__res_iclose(statp, false);
 			/* don't retry if called from dig */
 			if (!statp->pfcode)
@@ -1405,6 +1417,7 @@ send_dg(res_state statp,
 					retval = reopen (statp, terrno, ns);
 					if (retval <= 0)
 						return retval;
+					pfd[0].fd = EXT(statp).nssocks[ns];
 				}
 			}
 			goto wait;
diff --git a/resolv/rpc/netdb.h b/resolv/rpc/netdb.h
new file mode 100644
index 0000000000..eecea3cb06
--- /dev/null
+++ b/resolv/rpc/netdb.h
@@ -0,0 +1,3 @@
+/* This is a dummy file for <rpc/netdb.h>, which is included by <netdb.h>.
+   This file is installed when the C library does not support the SunRPC
+   interfaces (including 'struct rpcent' et al) at all.  */
diff --git a/resolv/tst-inet_ntop.c b/resolv/tst-inet_ntop.c
index f968ec4dcb..f0de06306c 100644
--- a/resolv/tst-inet_ntop.c
+++ b/resolv/tst-inet_ntop.c
@@ -4,8 +4,8 @@
 #include <stdio.h>
 #include <string.h>
 
-int
-main (void)
+static int
+do_test (void)
 {
   struct in_addr addr4;
   struct in6_addr addr6;
@@ -109,3 +109,6 @@ main (void)
 
   return result;
 }
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/resolv/tst-leaks.c b/resolv/tst-leaks.c
index e1f42f1264..290d936cd4 100644
--- a/resolv/tst-leaks.c
+++ b/resolv/tst-leaks.c
@@ -1,5 +1,5 @@
 /* Tests for res_query in libresolv
-   Copyright (C) 2003-2014 Free Software Foundation, Inc.
+   Copyright (C) 2003-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/resolv/tst-leaks2.c b/resolv/tst-leaks2.c
index b964ae7435..dfb7ca26b0 100644
--- a/resolv/tst-leaks2.c
+++ b/resolv/tst-leaks2.c
@@ -1,5 +1,5 @@
 /* Tests for res_init in libresolv
-   Copyright (C) 2004-2014 Free Software Foundation, Inc.
+   Copyright (C) 2004-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/resolv/tst-res_hconf_reorder.c b/resolv/tst-res_hconf_reorder.c
new file mode 100644
index 0000000000..1e7e0e2fa5
--- /dev/null
+++ b/resolv/tst-res_hconf_reorder.c
@@ -0,0 +1,112 @@
+/* BZ #17977 _res_hconf_reorder_addrs test.
+
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+static struct timespec ts;
+
+/* The first thread that gets a lock in _res_hconf_reorder_addrs()
+   should hold the lock long enough to make two other threads blocked.
+   This is achieved by slowing down realloc(3) that is called several times
+   by _res_hconf_reorder_addrs().  */
+
+void *
+realloc (void *ptr, size_t len)
+{
+  static void *(*fun) (void *, size_t);
+
+  if (!fun)
+    fun = dlsym (RTLD_NEXT, "realloc");
+
+  if (ts.tv_nsec)
+    nanosleep (&ts, NULL);
+
+  return (*fun) (ptr, len);
+}
+
+static void *
+resolve (void *arg)
+{
+  struct in_addr addr;
+  struct hostent ent;
+  struct hostent *result;
+  int err;
+  char buf[1024];
+
+  addr.s_addr = htonl (INADDR_LOOPBACK);
+  (void) gethostbyaddr_r ((void *) &addr, sizeof (addr), AF_INET,
+		          &ent, buf, sizeof (buf), &result, &err);
+  return arg;
+}
+
+static int
+do_test (void)
+{
+  #define N 3
+  pthread_t thr[N];
+  unsigned int i;
+  int result = 0;
+
+  /* turn on realloc slowdown */
+  ts.tv_nsec = 100000000;
+
+  for (i = 0; i < N; ++i)
+    {
+      int rc = pthread_create (&thr[i], NULL, resolve, NULL);
+
+      if (rc)
+	{
+	  printf ("pthread_create: %s\n", strerror(rc));
+	  exit (1);
+	}
+    }
+
+  for (i = 0; i < N; ++i)
+    {
+      void *retval;
+      int rc = pthread_join (thr[i], &retval);
+
+      if (rc)
+	{
+	  printf ("pthread_join: %s\n", strerror(rc));
+	  exit (1);
+	}
+      if (retval)
+	{
+	  printf ("thread %u exit status %p\n", i, retval);
+	  result = 1;
+	}
+    }
+
+  /* turn off realloc slowdown, no longer needed */
+  ts.tv_nsec = 0;
+
+  return result;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"