From 35cbb5791d143cf5c552e92f46e18b15e7385ac7 Mon Sep 17 00:00:00 2001
From: Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
Date: Tue, 25 Sep 2012 18:15:13 +0200
Subject: [PATCH] fixes issue 156: monkeypatch class level descriptors

---
 CHANGELOG                   |  3 ++-
 _pytest/monkeypatch.py      |  6 +++++-
 testing/test_monkeypatch.py | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 497c4d939..7de71184e 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -56,7 +56,8 @@ Changes between 2.2.4 and 2.3.0.dev
 - fix issue 188: ensure sys.exc_info is clear on python2
                  before calling into a test
 
-- fix issue 191: addd unittest TestCase runTest method support
+- fix issue 191: add unittest TestCase runTest method support
+- fix issue 156: monkeypatch correctly handles class level descriptors
 
 - reporting refinements:
 
diff --git a/_pytest/monkeypatch.py b/_pytest/monkeypatch.py
index 862904431..292e4f76e 100644
--- a/_pytest/monkeypatch.py
+++ b/_pytest/monkeypatch.py
@@ -1,6 +1,6 @@
 """ monkeypatching and mocking functionality.  """
 
-import os, sys
+import os, sys, inspect
 
 def pytest_funcarg__monkeypatch(request):
     """The returned ``monkeypatch`` funcarg provides these
@@ -39,6 +39,10 @@ class monkeypatch:
         oldval = getattr(obj, name, notset)
         if raising and oldval is notset:
             raise AttributeError("%r has no attribute %r" %(obj, name))
+
+        # avoid class descriptors like staticmethod/classmethod
+        if inspect.isclass(obj):
+            oldval = obj.__dict__.get(name, notset)
         self._setattr.insert(0, (obj, name, oldval))
         setattr(obj, name, value)
 
diff --git a/testing/test_monkeypatch.py b/testing/test_monkeypatch.py
index 1fafb73e5..7a6150d0e 100644
--- a/testing/test_monkeypatch.py
+++ b/testing/test_monkeypatch.py
@@ -206,3 +206,38 @@ def test_issue185_time_breaks(testdir):
     result.stdout.fnmatch_lines("""
         *1 passed*
     """)
+
+
+
+class SampleNew(object):
+    @staticmethod
+    def hello():
+        return True
+
+
+class SampleNewInherit(SampleNew):
+    pass
+
+
+class SampleOld:
+    #oldstyle on python2
+    @staticmethod
+    def hello():
+        return True
+
+class SampleOldInherit(SampleOld):
+    pass
+
+
+@pytest.mark.parametrize('Sample', [
+    SampleNew, SampleNewInherit,
+    SampleOld, SampleOldInherit,
+], ids=['new', 'new-inherit', 'old', 'old-inherit'])
+def test_issue156_undo_staticmethod(Sample):
+    monkeypatch = MonkeyPatch()
+
+    monkeypatch.setattr(Sample, 'hello', None)
+    assert Sample.hello is None
+
+    monkeypatch.undo()
+    assert Sample.hello()