Fix #728: attrib plugin rejects any staticmethod

The issue is that static methods get wrapped in an UnboundMethod object,
and the attribute plugin is unable to grab the associated class, since
UnboundMethod does not have the im_class attribute.  Since the goal of
UnboundMethod is to mimic an actual method, let's go ahead and implement
the im_class attribute.

CHANGELOG

@@ -67,6 +67,8 @@ In Development
 - Fix #771: attr plugin is broken when parent and child share same method
   name with different attributes
   Patch by John Szakmeister.  Test case provided by Thomas Grainger.
+- Fix #728: attrib plugin rejects any staticmethod
+  Patch by John Szakmesiter.  Test case provided by Thomas Kluyver.
 
 1.3.0
 

functional_tests/test_attribute_plugin.py

@@ -170,6 +170,16 @@ def verify(self):
         assert 'TestDerived' not in self.output
 
 
+# Issue #728
+class TestStaticMethod(AttributePluginTester):
+    suitepath = os.path.join(support, 'attrib-static')
+    args = ["-a", "!slow"]
+
+    def verify(self):
+        assert 'test.TestAttrib.test_static ... ok' in self.output
+        assert 'Ran 1 test' in self.output
+
+
 if compat_24:
     class TestAttributeEval(AttributePluginTester):
         args = ["-A", "c>20"]

nose/pyversion.py

@@ -89,6 +89,7 @@ def __init__(self, cls, func):
         self.__dict__ = func.__dict__.copy()
         self._func = func
         self.__self__ = UnboundSelf(cls)
+        self.im_class = cls
 
     def address(self):
         cls = self.__self__.cls