New test for just-fixed bug in ftw.c.

tests/du/restore-wd

@@ -0,0 +1,32 @@
+#!/bin/sh
+# due to a bug in glibc's ftw.c, in some cases, nftw w/FTW_CHDIR
+# would not restore the working directory.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  du --version
+fi
+
+pwd=`pwd`
+t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
+trap 'status=$?; cd $pwd; chmod -R u+rwx $t0; rm -rf $t0 && exit $status' 0
+trap '(exit $?); exit $?' 1 2 13 15
+
+framework_failure=0
+mkdir -p $tmp || framework_failure=1
+cd $tmp || framework_failure=1
+mkdir a b || framework_failure=1
+
+if test $framework_failure = 1; then
+  echo "$0: failure in testing framework" 1>&2
+  (exit 1); exit 1
+fi
+
+fail=0
+
+# With du from coreutils-4.5.5 and 4.5.6, this would fail with
+# du: `b': No such file or directory
+
+du a b > out || fail=1
+
+(exit $fail); exit $fail