Fixed inconsistent File.directory? behavior

lib/fakefs.rb

@@ -112,7 +112,8 @@ module FakeFS
       if path.respond_to? :entry
         path.entry.is_a? MockDir
       else
-        FileSystem.find(path).entry.is_a? MockDir
+        result = FileSystem.find(path)
+        result ? result.entry.is_a?(MockDir) : false
       end
     end
 

test/fakefs_test.rb

@@ -42,6 +42,11 @@ class FakeFSTest < Test::Unit::TestCase
     assert File.directory?(sympath)
   end
 
+  def test_knows_non_existent_directories_arent_directories
+    path = 'does/not/exist/'
+    assert_equal RealFile.directory?(path), File.directory?(path)
+  end
+
   def test_doesnt_overwrite_existing_directories
     FileUtils.mkdir_p(path = "/path/to/dir")
     assert File.exists?(path)