FIX: fix doctest error with empty output

The numpy doctest extension generates an error with empty doctest output;
this most often comes about with the +SKIP option.

The numpy doctest plugin exposed a nose bug because it accidentally used
a different default for the 'doctest-result-variable'.

nose bug report here:
http://code.google.com/p/python-nose/issues/detail?id=445

2 files changed, 21 insertions, 1 deletions

diff --git a/numpy/testing/noseclasses.py b/numpy/testing/noseclasses.py
index 25f6662b7..74b886fed 100644
--- a/numpy/testing/noseclasses.py
+++ b/numpy/testing/noseclasses.py
@@ -196,6 +196,7 @@ class NumpyDoctest(npd.Doctest):
         self.doctest_tests = True
         self.finder = NumpyDocTestFinder()
         self.parser = doctest.DocTestParser()
+        self.doctest_result_var = None # default in npd.Doctest
         if self.enabled:
             # Pull standard doctest out of plugin list; there's no reason to run
             # both.  In practice the Unplugger plugin above would cover us when
@@ -254,7 +255,8 @@ class NumpyDoctest(npd.Doctest):
 
             yield NumpyDocTestCase(test,
                                    optionflags=optionflags,
-                                   checker=NumpyOutputChecker())
+                                   checker=NumpyOutputChecker(),
+                                   result_var = self.doctest_result_var)
 
 
     # Add an afterContext method to nose.plugins.doctests.Doctest in order
diff --git a/numpy/testing/tests/test_doctesting.py b/numpy/testing/tests/test_doctesting.py
index a9f790208..a34071128 100644
--- a/numpy/testing/tests/test_doctesting.py
+++ b/numpy/testing/tests/test_doctesting.py
@@ -26,6 +26,24 @@ def check_whitespace_enabled():
      7
     '''
 
+def check_empty_output():
+    """ Check that no output does not cause an error.
+
+    This is related to nose bug 445; the numpy plugin changed the
+    doctest-result-variable default and therefore hit this bug:
+    http://code.google.com/p/python-nose/issues/detail?id=445
+
+    >>> a = 10
+    """
+
+def check_skip():
+    """ Check skip directive
+
+    The test below should not run
+
+    >>> 1/0 #doctest: +SKIP
+    """
+
 
 if __name__ == '__main__':
     # Run tests outside numpy test rig