rm could be tricked into mistakenly reporting a cycle

diff --git a/tests/rm/cycle b/tests/rm/cycle
new file mode 100755 (executable)
index 0000000..4d3467b
--- /dev/null
+++ b/tests/rm/cycle
@@ -0,0 +1,39 @@
+#!/bin/sh
+# rm (coreutils-4.5.4) could be tricked into mistakenly reporting a cycle.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  rm --version
+fi
+
+. $srcdir/../lang-default
+
+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 -p a/b
+touch a/b/file
+chmod u-w a/b
+
+if test $framework_failure = 1; then
+  echo "$0: failure in testing framework" 1>&2
+  (exit 1); exit 1
+fi
+
+fail=0
+
+rm -rf a a 2>&1 | sed 's/:[^:]*$//' > out || fail=1
+cat <<\EOF > exp
+rm: cannot remove `a/b/file'
+rm: cannot remove `a/b/file'
+EOF
+
+cmp out exp || fail=1
+test $fail = 1 && diff out exp 2> /dev/null
+
+(exit $fail); exit $fail