tests: exercise du's --max-depth option

* tests/Makefile.am (TESTS): Add du/max-depth.
* tests/du/max-depth: New file.

tests/Makefile.am

@@ -350,6 +350,7 @@ TESTS =						\
   du/inaccessible-cwd				\
   du/long-from-unreadable			\
   du/long-sloop					\
+  du/max-depth					\
   du/no-deref					\
   du/no-x					\
   du/one-file-system				\

tests/du/max-depth

@@ -0,0 +1,31 @@
+#!/bin/sh
+# exercise du's --max-depth=N option
+
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program 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 General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+
+mkdir -p a/b/c/d/e || framework_failure_
+printf 'a/b/c\na/b\na\n' > exp || framework_failure_
+
+du --max-depth=2 a > out 2>err || fail=1
+
+# Remove the sizes.  They vary between file systems.
+cut -f2- out > k && mv k out
+compare out exp || fail=1
+compare err /dev/null || fail=1
+
+Exit $fail