create the dummy app if there's no test_unit but there's a dummy_path

railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb

@@ -202,7 +202,7 @@ def create_test_files
       end
 
       def create_test_dummy_files
-        return if options[:skip_test_unit]
+        return if options[:skip_test_unit] && options[:dummy_path] == 'test/dummy'
         create_dummy_app
       end
 

railties/test/generators/plugin_new_generator_test.rb

@@ -182,6 +182,13 @@ def test_passing_dummy_path_as_a_parameter
     assert_file "spec/dummy/config/application.rb"
     assert_no_file "test/dummy"
   end
+  
+  def test_creating_dummy_without_tests_but_with_dummy_path
+    run_generator [destination_root, "--dummy_path", "spec/dummy", "--skip-test-unit"]
+    assert_file "spec/dummy"
+    assert_file "spec/dummy/config/application.rb"
+    assert_no_file "test"
+  end
 
   def test_skipping_gemspec
     run_generator [destination_root, "--skip-gemspec"]