Issue #25663: Make rlcompleter avoid duplicate global names

1 files changed, 21 insertions, 0 deletions

diff --git a/Lib/test/test_rlcompleter.py b/Lib/test/test_rlcompleter.py
index 927df34..0b3918b 100644
--- a/Lib/test/test_rlcompleter.py
+++ b/Lib/test/test_rlcompleter.py
@@ -85,6 +85,27 @@ class TestRlcompleter(unittest.TestCase):
         self.assertEqual(completer.complete('as', 2), 'assert')
         self.assertEqual(completer.complete('an', 0), 'and')
 
+    def test_duplicate_globals(self):
+        namespace = {
+            'False': None,  # Keyword vs builtin vs namespace
+            'assert': None,  # Keyword vs namespace
+            'try': lambda: None,  # Keyword vs callable
+            'memoryview': None,  # Callable builtin vs non-callable
+            'Ellipsis': lambda: None,  # Non-callable builtin vs callable
+        }
+        completer = rlcompleter.Completer(namespace)
+        self.assertEqual(completer.complete('False', 0), 'False')
+        self.assertIsNone(completer.complete('False', 1))  # No duplicates
+        self.assertEqual(completer.complete('assert', 0), 'assert')
+        self.assertIsNone(completer.complete('assert', 1))
+        self.assertEqual(completer.complete('try', 0), 'try')
+        self.assertIsNone(completer.complete('try', 1))
+        # No opening bracket "(" because we overrode the built-in class
+        self.assertEqual(completer.complete('memoryview', 0), 'memoryview')
+        self.assertIsNone(completer.complete('memoryview', 1))
+        self.assertEqual(completer.complete('Ellipsis', 0), 'Ellipsis(')
+        self.assertIsNone(completer.complete('Ellipsis', 1))
+
 
 if __name__ == '__main__':
     unittest.main()