xunit plugin does not throw exception when missing step definition

lettuce/plugins/xunit_output.py

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from datetime import datetime
+from datetime import datetime, timedelta
 from lettuce.terrain import after
 from lettuce.terrain import before
 from xml.dom import minidom
@@ -56,7 +56,10 @@ def enable(filename=None):
         tc = doc.createElement("testcase")
         tc.setAttribute("classname", classname.encode('utf-8'))
         tc.setAttribute("name", step.sentence.encode('utf-8'))
-        tc.setAttribute("time", str(total_seconds((datetime.now() - step.started))))
+        try:
+            tc.setAttribute("time", str(total_seconds((datetime.now() - step.started))))
+        except AttributeError:
+            tc.setAttribute("time", str(total_seconds(timedelta(seconds=0))))
 
         if not step.ran:
             skip=doc.createElement("skipped")

tests/functional/output_features/missing_steps/missing_steps.feature

+Feature: Missing steps do not cause the xunit plugin to throw
+  Scenario: It should pass
+    Given my sdfsdf sdfsdf sdfs df sdfsdf

tests/functional/test_xunit_output.py

@@ -120,4 +120,17 @@ def test_xunit_output_with_unicode_characters_in_error_messages():
     assert_equals(1, len(called), "Function not called")
     xunit_output.wrt_output = old
 
+@with_setup(prepare_stdout, registry.clear)
+def test_xunit_does_not_throw_exception_when_missing_step_definition():
+    def dummy_write(filename, content):
+        pass
+
+    old = xunit_output.wrt_output
+    xunit_output.wrt_output = dummy_write
+    runner = Runner(feature_name('missing_steps'), enable_xunit=True,
+                    xunit_filename="mising_steps.xml")
+    runner.run()
+
+    xunit_output.wrt_output = old
+