Fix filter_clear signature and address review feedback

Author: tangyuan0821

Lib/test/test_builtin.py

@@ -1132,8 +1132,6 @@ 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

Misc/NEWS.d/next/Core_and_Builtins/2025-08-18-08-14-52.gh-issue-137894.SrkIA_.rst

@@ -1,6 +1,3 @@
-Fix segmentation fault in deeply nested :func:`filter` iterator chains by
-adding a ``tp_clear`` method to the filter object. Previously, creating
-thousands of nested filter iterators and then consuming them would cause
-a stack overflow during garbage collection, leading to interpreter crashes.
-Now such cases properly raise :exc:`RecursionError` instead of crashing
-the interpreter.
+Fix segmentation fault in deeply nested :func:`filter` iterator chains.
+Deeply nested filter iterators now properly raise :exc:`RecursionError`
+instead of crashing the interpreter.

Python/bltinmodule.c

@@ -580,8 +580,9 @@ filter_traverse(PyObject *self, visitproc visit, void *arg)
 }
 
 static int
-filter_clear(filterobject *lz)
+filter_clear(PyObject *self)
 {
+    filterobject *lz = _filterobject_CAST(self);
     Py_CLEAR(lz->it);
     Py_CLEAR(lz->func);
     return 0;
@@ -668,7 +669,7 @@ PyTypeObject PyFilter_Type = {
     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
         Py_TPFLAGS_BASETYPE,            /* tp_flags */
     filter_doc,                         /* tp_doc */
-    (traverseproc)filter_traverse,      /* tp_traverse */
+    filter_traverse,                    /* tp_traverse */
     (inquiry)filter_clear,              /* tp_clear */
     0,                                  /* tp_richcompare */
     0,                                  /* tp_weaklistoffset */