From ca04e784b703dd5ccd830e957a2aaf3823efbee4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marta=20G=C3=B3mez=20Mac=C3=ADas?= <mgmacias@google.com>
Date: Sat, 4 Mar 2023 20:50:43 +0100
Subject: [PATCH 1/3] Add thrashcan macros to filter object dealloc

---
 Lib/test/test_builtin.py | 10 ++++++++++
 Python/bltinmodule.c     |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 9e19af0ae90fc1..e7a79bc13b7f3d 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -926,6 +926,16 @@ def test_filter_pickle(self):
             f2 = filter(filter_char, "abcdeabcde")
             self.check_iter_pickle(f1, list(f2), proto)
 
+    def test_filter_dealloc(self):
+        # Tests recursive deallocation of nested filter objects using the
+        # thrashcan mechanism. See gh-102356 for more details.
+        max_iters = 1000000
+        i = filter(bool, range(max_iters))
+        for _ in range(max_iters):
+            i = filter(bool, i)
+        del i
+        gc.collect()
+
     def test_getattr(self):
         self.assertTrue(getattr(sys, 'stdout') is sys.stdout)
         self.assertRaises(TypeError, getattr)
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 53439ab16040c4..12ca0ba6c4873c 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -553,9 +553,11 @@ static void
 filter_dealloc(filterobject *lz)
 {
     PyObject_GC_UnTrack(lz);
+    Py_TRASHCAN_BEGIN(lz, filter_dealloc)
     Py_XDECREF(lz->func);
     Py_XDECREF(lz->it);
     Py_TYPE(lz)->tp_free(lz);
+    Py_TRASHCAN_END
 }
 
 static int

From 2c686386ce9bd698ded198ea28ac0454c839e8f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marta=20G=C3=B3mez=20Mac=C3=ADas?= <mgmacias@google.com>
Date: Sat, 4 Mar 2023 20:53:50 +0100
Subject: [PATCH 2/3] Add myself to ACKS

---
 Misc/ACKS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Misc/ACKS b/Misc/ACKS
index c591cd3bfe4b9e..7bbde3af99782b 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -637,6 +637,7 @@ Tim Golden
 Yonatan Goldschmidt
 Mark Gollahon
 Mikhail Golubev
+Marta Gómez Macías
 Guilherme Gonçalves
 Tiago Gonçalves
 Chris Gonnerman

From 9adcdf798bd76739e2234bce9529458808138977 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marta=20G=C3=B3mez=20Mac=C3=ADas?= <mgmacias@google.com>
Date: Sat, 4 Mar 2023 20:56:27 +0100
Subject: [PATCH 3/3] Add news entry

---
 .../2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst              | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst b/Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst
new file mode 100644
index 00000000000000..c03fd5266bc301
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst	
@@ -0,0 +1,2 @@
+Fix a bug that caused a crash when deallocating deeply nested filter
+objects. Patch by Marta Gómez Macías.