do a deep copy of the hash

lib/fakefs.rb

@@ -387,7 +387,7 @@ module FakeFS
     end
 
     def clone(parent)
-      clone = super()
+      clone = Marshal.load(Marshal.dump(self))
       clone.each do |key, value|
         value.parent = parent
       end

test/fakefs_test.rb

@@ -197,8 +197,10 @@ class FakeFSTest < Test::Unit::TestCase
     FileUtils.mkdir_p '/path/bar'
     File.open('/path/bar/baz', 'w'){|f| f.write 'foo' }
 
+    FileUtils.cp_r '/path/bar', '/path/bar2'
+
     assert_equal  ['/path'], Dir['/path']
-    assert_equal ['/path/bar', '/path/foo', '/path/foobar'], Dir['/path/*']
+    assert_equal %w( /path/bar /path/bar2 /path/foo /path/foobar ), Dir['/path/*']
 
     assert_equal ['/path/bar/baz'], Dir['/path/bar/*']