From 5d0abb69715b9638f26c896444643055ec2ef038 Mon Sep 17 00:00:00 2001
From: Mikhail Efimov <efimov.mikhail@gmail.com>
Date: Mon, 20 Oct 2025 13:45:07 +0300
Subject: [PATCH] gh-139951: Test on GC collection disabled if threshold is
 zero (GH-140304)

---
 Lib/test/test_gc.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index 432890905346..70d9d009fa8b 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -1559,6 +1559,20 @@ class GCTogglingTests(unittest.TestCase):
         finally:
             gc.enable()
 
+    # Ensure that setting *threshold0* to zero disables collection.
+    @gc_threshold(0)
+    def test_threshold_zero(self):
+        junk = []
+        i = 0
+        detector = GC_Detector()
+        while not detector.gc_happened:
+            i += 1
+            if i > 50000:
+                break
+            junk.append([])  # this may eventually trigger gc (if it is enabled)
+
+        self.assertEqual(i, 50001)
+
 
 class PythonFinalizationTests(unittest.TestCase):
     def test_ast_fini(self):
-- 
2.47.3