BZ#16469: don't drop trailing dot in res_nquerydomain(..., name, NULL, ...)

If we drop it here, we will fail to detect a duplicate trailing dot
later on.  Retaining, OTOH, has no ill effects whatsoever, and it even
saves us the trouble of copying the domain name minus the trailing
dot, like we used to do.

for ChangeLog

	[BZ #16469]
	* NEWS: Update.
	* resolv/res_query.c (__libc_res_nquerydomain): Retain
	trailing dot.
	* posix/tst-getaddrinfo5.c: New.
	* posix/Makefile (tests): Add it.

1 files changed, 69 insertions, 0 deletions

diff --git a/posix/tst-getaddrinfo5.c b/posix/tst-getaddrinfo5.c
new file mode 100644
index 0000000000..cfebb9b9ce
--- /dev/null
+++ b/posix/tst-getaddrinfo5.c
@@ -0,0 +1,69 @@
+/* Test host lookup with double dots at the end, [BZ #16469].
+   Copyright (C) 2014 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 <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <string.h>
+
+static int
+test (void)
+{
+  static char host1[] = "localhost..";
+  static char host2[] = "www.gnu.org..";
+  static char *hosts[] = { host1, host2 };
+  int i;
+  int pass = 0;
+
+  for (i = 0; i < sizeof (hosts) / sizeof (*hosts); i++)
+    {
+      char *host = hosts[i];
+      size_t len = strlen (host);
+      struct addrinfo *ai;
+
+      /* If the name doesn't resolve with a single dot at the
+	 end, skip it.  */
+      host[len-1] = 0;
+      if (getaddrinfo (host, NULL, NULL, &ai) != 0)
+	{
+	  printf ("resolving \"%s\" failed, skipping this hostname\n", host);
+	  continue;
+	}
+      printf ("resolving \"%s\" worked, proceeding to test\n", host);
+      freeaddrinfo (ai);
+
+      /* If it resolved with a single dot, check that it doesn't with
+	 a second trailing dot.  */
+      host[len-1] = '.';
+      if (getaddrinfo (host, NULL, NULL, &ai) == 0)
+	{
+	  printf ("resolving \"%s\" worked, test failed\n", host);
+	  return 1;
+	}
+      printf ("resolving \"%s\" failed, test passed\n", host);
+      pass = 1;
+    }
+
+  /* We want at least one successful name resolution for the test to
+     succeed.  */
+  return pass ? 0 : 2;
+}
+
+#define TEST_FUNCTION test ()
+#define TIMEOUT 10
+#include "../test-skeleton.c"