Add tests for filter object recursion and garbage collection handling

Author: tangyuan0821

Lib/test/test_builtin.py

@@ -1132,6 +1132,22 @@ def test_filter_dealloc(self):
         del i
         gc.collect()
 
+    @support.skip_wasi_stack_overflow()
+    @support.skip_emscripten_stack_overflow()
+    @support.requires_resource('cpu')
+    def test_filter_deep_nesting_recursion_error(self):
+        # gh-137894: Test that deeply nested filter() iterator chains
+        # raise RecursionError instead of causing segmentation fault.
+        # This verifies that the tp_clear method prevents stack overflow
+        # during garbage collection of cyclic references.
+        i = filter(bool, range(1000000))
+        for _ in range(100000):
+            i = filter(bool, i)
+        
+        # Should raise RecursionError, not segmentation fault
+        with self.assertRaises(RecursionError):
+            list(i)
+
     def test_getattr(self):
         self.assertTrue(getattr(sys, 'stdout') is sys.stdout)
         self.assertRaises(TypeError, getattr)