support_format_dns_packet: Fix CNAME and multiple RR handling

diff --git a/support/Makefile b/support/Makefile
index 2ace559..db7bb13 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -111,6 +111,7 @@  endif
 tests = \
   README-testing \
   tst-support-namespace \
+  tst-support_format_dns_packet \
   tst-support_record_failure \
 
 ifeq ($(run-built-tests),yes)
@@ -125,4 +126,6 @@  $(objpfx)tst-support_record_failure-2.out: tst-support_record_failure-2.sh \
 	$(evaluate-test)
 endif
 
+$(objpfx)tst-support_format_dns_packet: $(common-objpfx)resolv/libresolv.so
+
 include ../Rules
diff --git a/support/support_format_dns_packet.c b/support/support_format_dns_packet.c
index 21fe7e5..d56b820 100644
--- a/support/support_format_dns_packet.c
+++ b/support/support_format_dns_packet.c
@@ -174,7 +174,7 @@  support_format_dns_packet (const unsigned char *buffer, size_t length)
           goto out;
         }
       /* Skip non-matching record types.  */
-      if (rtype != qtype || rclass != qclass)
+      if ((rtype != qtype && rtype != T_CNAME) || rclass != qclass)
         continue;
       switch (rtype)
         {
@@ -201,7 +201,7 @@  support_format_dns_packet (const unsigned char *buffer, size_t length)
         case T_PTR:
           {
             struct dname name;
-            if (extract_name (full, &in, &name))
+            if (extract_name (full, &rdata, &name))
               fprintf (mem.out, "name: %s\n", name.name);
             else
               fprintf (mem.out, "error: malformed CNAME/PTR record\n");
diff --git a/support/tst-support_format_dns_packet.c b/support/tst-support_format_dns_packet.c
new file mode 100644
index 0000000..eb174e2
--- /dev/null
+++ b/support/tst-support_format_dns_packet.c
@@ -0,0 +1,62 @@ 
+/* Tests for the support_format_dns_packet function.
+   Copyright (C) 2016-2017 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 <support/check.h>
+#include <support/format_nss.h>
+
+static void
+test_multiple_cnames (void)
+{
+  static const char packet[] =
+    /* Header: Response with three records.  */
+    "\x12\x34\x80\x00\x00\x01\x00\x03\x00\x00\x00\x00"
+    /* Question section.  www.example/IN/A.  */
+    "\x03www\x07""example\x00\x00\x01\x00\x01"
+    /* Answer section.  www.example CNAME www1.example.  */
+    "\xc0\x0c"
+    "\x00\x05\x00\x01\x00\x00\x00\x00\x00\x07"
+    "\x04www1\xc0\x10"
+    /* www1 CNAME www2.  */
+    "\x04www1\xc0\x10"
+    "\x00\x05\x00\x01\x00\x00\x00\x00\x00\x07"
+    "\x04www2\xc0\x10"
+    /* www2 A 192.0.2.1.  */
+    "\x04www2\xc0\x10"
+    "\x00\x01\x00\x01\x00\x00\x00\x00\x00\x04"
+    "\xc0\x00\x02\x01";
+
+  char *formatted = support_format_dns_packet
+    ((unsigned char *) packet, sizeof (packet) - 1);
+  puts ("info: test_multiple_cnames output:");
+  puts (formatted);
+  TEST_VERIFY (strcmp (formatted,
+                       "name: www.example\n"
+                       "name: www1.example\n"
+                       "name: www2.example\n"
+                       "address: 192.0.2.1\n") == 0);
+  free (formatted);
+}
+
+static int
+do_test (void)
+{
+  test_multiple_cnames ();
+  return 0;
+}
+
+#include <support/test-driver.c>