fixing FileUtils.mv

lib/fakefs.rb

@@ -30,7 +30,7 @@ module FakeFS
 
     def mv(src, dest)
       if target = FileSystem.find(src)
-        FileSystem.add(dest, target.entry)
+        FileSystem.add(dest, target.entry.clone)
         FileSystem.delete(src)
       else
         raise Errno::ENOENT, src

test/fakefs_test.rb

@@ -265,4 +265,10 @@ class FakeFSTest < Test::Unit::TestCase
       FileUtils.mv 'blafgag', 'foo'
     end
   end
+
+  def test_mv_actually_works
+    File.open('foo', 'w') {|f| f.write 'bar' }
+    FileUtils.mv 'foo', 'baz'
+    assert_equal 'bar', File.open('baz'){|f| f.read }
+  end
 end