localedef: Add tests-container test for --no-hard-links.

diff --git a/ChangeLog b/ChangeLog
index e538327f59..539a377b8a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@ 
+2018-12-10  Carlos O'Donell  <carlos@redhat.com>
+
+	* localedata/Makefile (tests-container): Add tst-localedef-hardlinks.
+	* localedata/tst-localedef-hardlinks.c: New file.
+	* localedata/tst-localedef-hardlinks.root/postclean.req: Likewise.
+	* localedata/tst-localedef-hardlinks.root/test1_locale: Likewise.
+	* localedata/tst-localedef-hardlinks.root/test2_locale: Likewise.
+	* localedata/tst-localedef-hardlinks.root/tst-localedef-hardlinks.script: Likewise
+
 2018-12-10  Carlos O'Donell  <carlos@redhat.com>
 
 	* support/Makefile (CFLAGS-support_paths.c): Add -DI18NDIR_PATH
diff --git a/localedata/Makefile b/localedata/Makefile
index b245f0ff54..ecc0bd611e 100644
--- a/localedata/Makefile
+++ b/localedata/Makefile
@@ -165,6 +165,8 @@  tests-special += $(objpfx)mtrace-tst-leaks.out
 endif
 endif
 endif
+tests-container = \
+			tst-localedef-hardlinks
 
 # Files to install.
 install-others := $(addprefix $(inst_i18ndir)/, \
diff --git a/localedata/tst-localedef-hardlinks.c b/localedata/tst-localedef-hardlinks.c
new file mode 100644
index 0000000000..48baa425cd
--- /dev/null
+++ b/localedata/tst-localedef-hardlinks.c
@@ -0,0 +1,111 @@ 
+/* Test --no-hard-links option to localedef.
+   Copyright (C) 2018 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/>.  */
+
+/* The test is designed to run in a container and execute localedef
+   once without --no-hard-links, verify that there are 2 hard links to
+   LC_CTYPE, and then run again *with* --no-hard-links and verify there
+   are no hard links and link counts remain at 1.  The expectation here
+   is that LC_CTYPE is identical for both locales because they are same
+   empty locale but with a different name.  We use tests-container in
+   this test because the hard link optimziation is only carried out for
+   the default locale installation directory, and to write to that we
+   need write access to that directory, enabled by 'su' via
+   tests-container framework.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+
+/* Each step of the test compiles a locale to output, and has an expected
+   link count for LC_CTYPE.  */
+struct step_data
+{
+  const char *compile;
+  const char *output;
+  int expected_link;
+};
+
+/* Carry out one step of compile and test for link count.  */
+void
+compile_and_test_link (struct step_data step)
+{
+  int ret;
+  struct stat64 locale;
+  char *output;
+
+  ret = system (step.compile);
+
+  /* The source locales are empty and so localedef exists with error
+     code 1 from the warnings, but that's OK.  We want to look at
+     the produced files and their link counts only.  */
+  if (WEXITSTATUS(ret) == 1)
+    {
+      output = xasprintf ("%s/%s", support_complocaledir_prefix, step.output);
+      xstat (output, &locale);
+      free (output);
+      TEST_COMPARE (locale.st_nlink, step.expected_link);
+    }
+  else
+    FAIL_EXIT1 ("system: %d\n", ret);
+
+}
+
+#define TEST1DIR "test1_locale.dir"
+#define TEST2DIR "test2_locale.dir"
+
+/* The whole test has 4 steps described below.  */
+static struct step_data step[] = {
+  { "/usr/bin/localedef --no-archive -i /test1_locale " TEST1DIR,
+    TEST1DIR "/LC_CTYPE", 1 },
+  { "/usr/bin/localedef --no-archive -i /test2_locale " TEST2DIR,
+    TEST2DIR "/LC_CTYPE", 2 },
+  { "/usr/bin/localedef --no-archive " \
+    "--no-hard-links -i /test1_locale " TEST1DIR,
+    TEST1DIR "/LC_CTYPE", 1 },
+  { "/usr/bin/localedef --no-archive " \
+    "--no-hard-links -i /test2_locale " TEST1DIR,
+    TEST2DIR "/LC_CTYPE", 1 },
+};
+
+static int
+do_test (void)
+{
+  /* Compile the first locale.  */
+  compile_and_test_link (step[0]);
+
+  /* This time around we should have link counts of 2 for the second
+     linked locale since categories are identical.  */
+  compile_and_test_link (step[1]);
+
+  /* Again with --no-hard-links (link count is always one).  */
+  compile_and_test_link (step[2]);
+
+  /* Again with --no-hard-links, and the link count must remain 1.  */
+  compile_and_test_link (step[3]);
+
+  /* Tested without and with --no-hard-links and link counts were
+     consistent.  */
+  return EXIT_SUCCESS;
+}
+
+#include <support/test-driver.c>
diff --git a/localedata/tst-localedef-hardlinks.root/postclean.req b/localedata/tst-localedef-hardlinks.root/postclean.req
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/localedata/tst-localedef-hardlinks.root/test1_locale b/localedata/tst-localedef-hardlinks.root/test1_locale
new file mode 100644
index 0000000000..acaa15e288
--- /dev/null
+++ b/localedata/tst-localedef-hardlinks.root/test1_locale
@@ -0,0 +1,3 @@ 
+comment_char %
+escape_char /
+% Empty test1 locale.  Must be identical to test2 locale.
diff --git a/localedata/tst-localedef-hardlinks.root/test2_locale b/localedata/tst-localedef-hardlinks.root/test2_locale
new file mode 100644
index 0000000000..a46fed97f2
--- /dev/null
+++ b/localedata/tst-localedef-hardlinks.root/test2_locale
@@ -0,0 +1,3 @@ 
+comment_char %
+escape_char /
+% Empty test2 locale.  Must be identical to test1 locale.
diff --git a/localedata/tst-localedef-hardlinks.root/tst-localedef-hardlinks.script b/localedata/tst-localedef-hardlinks.root/tst-localedef-hardlinks.script
new file mode 100644
index 0000000000..2f33d333a6
--- /dev/null
+++ b/localedata/tst-localedef-hardlinks.root/tst-localedef-hardlinks.script
@@ -0,0 +1,14 @@ 
+# Need root to write to $i18ndir and $complocaledir when running localedef.
+su
+
+# A default install compresses charmaps with gzip.  This means that to
+# load a charmap you need gzip installed.  To avoid this we copy the
+# uncompressed charmap into place and use that instead.  This minimizes
+# the rootfs requirements.
+cp $S/localedata/charmaps/ANSI_X3.4-1968 $i18ndir/charmaps/ANSI_X3.4-1968
+
+# Create both compiled locale directories, this is required
+# by localedef, it won't create new directories to install
+# compiled files into.
+mkdirp 0755 $complocaledir/test1_locale.dir
+mkdirp 0755 $complocaledir/test2_locale.dir