add __file__ to the globals available for tests loaded via DocFileSuite;
this is useful for locating supporting data files, just as it is in Python
modules
diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py
index 0ae6b8d..fe4d863 100644
--- a/Lib/test/test_doctest.py
+++ b/Lib/test/test_doctest.py
@@ -2010,6 +2010,14 @@
modified the test globals. The test globals are
automatically cleared for us after a test.
+ Tests in a file run using `DocFileSuite` can also access the
+ `__file__` global, which is set to the name of the file
+ containing the tests:
+
+ >>> suite = doctest.DocFileSuite('test_doctest3.txt')
+ >>> suite.run(unittest.TestResult())
+ <unittest.TestResult run=1 errors=0 failures=0>
+
"""
def test_trailing_space_in_test():