robustify monkeypatch

CHANGELOG

@@ -1,3 +1,8 @@
+Changes between 2.2.1 and 2.2.2.dev
+----------------------------------------
+
+- make monkeypatch more robust against intermediate dict/env deletions
+
 Changes between 2.2.0 and 2.2.1
 ----------------------------------------
 

_pytest/__init__.py

@@ -1,2 +1,2 @@
 #
-__version__ = '2.2.1'
+__version__ = '2.2.2.dev1'

_pytest/monkeypatch.py

@@ -95,7 +95,7 @@ class monkeypatch:
         self._setattr[:] = []
         for dictionary, name, value in self._setitem:
             if value is notset:
-                del dictionary[name]
+                dictionary.pop(name, None)
             else:
                 dictionary[name] = value
         self._setitem[:] = []

setup.py

@@ -24,7 +24,7 @@ def main():
         name='pytest',
         description='py.test: simple powerful testing with Python',
         long_description = long_description,
-        version='2.2.1',
+        version='2.2.2.dev1',
         url='http://pytest.org',
         license='MIT license',
         platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],

testing/test_monkeypatch.py

@@ -59,6 +59,20 @@ def test_setitem():
     monkeypatch.undo()
     assert d['x'] == 5
 
+def test_setitem_deleted_meanwhile():
+    d = {}
+    monkeypatch = MonkeyPatch()
+    monkeypatch.setitem(d, 'x', 2)
+    del d['x']
+    monkeypatch.undo()
+    assert not d
+
+def test_setenv_deleted_meanwhile():
+    monkeypatch = MonkeyPatch()
+    monkeypatch.setenv('XYZ123', 'hello')
+    monkeypatch.undo()
+    assert 'XYZ123' not in os.environ
+
 def test_delitem():
     d = {'x': 1}
     monkeypatch = MonkeyPatch()