Issue #29392: Prevent crash when passing invalid arguments into msvcrt module.

1 files changed, 7 insertions, 0 deletions

diff --git a/Lib/test/test_optparse.py b/Lib/test/test_optparse.py
index 7621c24305..91a0319a73 100644
--- a/Lib/test/test_optparse.py
+++ b/Lib/test/test_optparse.py
@@ -16,6 +16,7 @@ from io import StringIO
 from test import support
 
 
+import optparse
 from optparse import make_option, Option, \
      TitledHelpFormatter, OptionParser, OptionGroup, \
      SUPPRESS_USAGE, OptionError, OptionConflictError, \
@@ -1650,6 +1651,12 @@ class TestParseNumber(BaseTest):
                              "option -l: invalid integer value: '0x12x'")
 
 
+class MiscTestCase(unittest.TestCase):
+    def test__all__(self):
+        blacklist = {'check_builtin', 'AmbiguousOptionError', 'NO_DEFAULT'}
+        support.check__all__(self, optparse, blacklist=blacklist)
+
+
 def test_main():
     support.run_unittest(__name__)