1 files changed, 17 insertions, 2 deletions
diff --git a/Lib/unittest/suite.py b/Lib/unittest/suite.py
index cde5d385ed..ca82765b9c 100644
--- a/Lib/unittest/suite.py
+++ b/Lib/unittest/suite.py
@@ -16,6 +16,8 @@ def _call_if_exists(parent, attr):
 class BaseTestSuite(object):
     """A simple test suite that doesn't provide class or module shared fixtures.
     """
+    _cleanup = True
+
     def __init__(self, tests=()):
         self._tests = []
         self.addTests(tests)
@@ -57,12 +59,22 @@ class BaseTestSuite(object):
             self.addTest(test)
 
     def run(self, result):
-        for test in self:
+        for index, test in enumerate(self):
             if result.shouldStop:
                 break
             test(result)
+            if self._cleanup:
+                self._removeTestAtIndex(index)
         return result
 
+    def _removeTestAtIndex(self, index):
+        """Stop holding a reference to the TestCase at index."""
+        try:
+            self._tests[index] = None
+        except TypeError:
+            # support for suite implementations that have overriden self._test
+            pass
+
     def __call__(self, *args, **kwds):
         return self.run(*args, **kwds)
 
@@ -87,7 +99,7 @@ class TestSuite(BaseTestSuite):
         if getattr(result, '_testRunEntered', False) is False:
             result._testRunEntered = topLevel = True
 
-        for test in self:
+        for index, test in enumerate(self):
             if result.shouldStop:
                 break
 
@@ -106,6 +118,9 @@ class TestSuite(BaseTestSuite):
             else:
                 test.debug()
 
+            if self._cleanup:
+                self._removeTestAtIndex(index)
+
         if topLevel:
             self._tearDownPreviousClass(None, result)
             self._handleModuleTearDown(result)