Attempt to fix sporadic travis-ci.org test failures (builds #429, #430)

Author: edschofield

src/future/backports/test/support.py

@@ -956,10 +956,12 @@ def _filterwarnings(filters, quiet=False):
     frame = sys._getframe(2)
     registry = frame.f_globals.get('__warningregistry__')
     if registry:
-        # Was: registry.clear()
-        # Py2-compatible:
-        for i in range(len(registry)):
-            registry.pop()
+        if utils.PY3:
+            registry.clear()
+        else:
+            # Py2-compatible:
+            for i in range(len(registry)):
+                registry.pop()
     with warnings.catch_warnings(record=True) as w:
         # Set filter "always" to record all warnings.  Because
         # test_warnings swap the module, we need to look up in

src/future/tests/base.py

@@ -9,12 +9,12 @@
 import functools
 from textwrap import dedent
 
-if not hasattr(unittest, 'skip'):
-    import unittest2 as unittest
-
 from future.utils import bind_method, PY26, PY3, PY2
 from future.moves.subprocess import check_output, STDOUT, CalledProcessError
 
+if PY26:
+    import unittest2 as unittest
+
 
 def reformat_code(code):
     """
@@ -369,29 +369,13 @@ def expectedFailurePY3(func):
 def expectedFailurePY26(func):
     if not PY26:
         return func
-    @functools.wraps(func)
-    def wrapper(*args, **kwargs):
-        try:
-            func(*args, **kwargs)
-        except Exception:
-            raise unittest.case._ExpectedFailure(sys.exc_info())
-        # The following contributes to a FAILURE on Py2.6 (with
-        # unittest2). Ignore it ...
-        # raise unittest.case._UnexpectedSuccess
-    return wrapper
+    return unittest.expectedFailure(func)
 
 
 def expectedFailurePY2(func):
     if not PY2:
         return func
-    @functools.wraps(func)
-    def wrapper(*args, **kwargs):
-        try:
-            func(*args, **kwargs)
-        except Exception:
-            raise unittest.case._ExpectedFailure(sys.exc_info())
-        raise unittest.case._UnexpectedSuccess
-    return wrapper
+    return unittest.expectedFailure(func)
 
 
 # Renamed in Py3.3: