From df43d6aba34c955a72613b8ca7fd9afa5ab0314d Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Fri, 21 Aug 2026 18:57:27 +0000
Subject: [PATCH 1/7] gh-156204: Guard recursion in PyErr_GivenExceptionMatches

---
 Lib/test/test_exceptions.py                     | 16 ++++++++++++++++
 ...26-08-21-18-49-12.gh-issue-156204.ZusA7e.rst |  3 +++
 Python/errors.c                                 | 17 +++++++++++------
 3 files changed, 30 insertions(+), 6 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst

diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index c34cf44d722456c..1aebdd5ba38fd5e 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -2778,6 +2778,22 @@ def test_except_star_invalid_exception_type(self):
             except (ValueError, 42):
                 pass
 
+    def test_given_exception_matches_deeply_nested_tuple(self):
+        import ctypes
+        lib = ctypes.pythonapi
+        lib.PyErr_GivenExceptionMatches.argtypes = [ctypes.py_object, ctypes.py_object]
+        lib.PyErr_GivenExceptionMatches.restype = ctypes.c_int
+
+        tup = (1, ValueError)
+        for _ in range(50_000):
+            tup = (1, tup)
+
+        # PyErr_GivenExceptionMatches should handle deep recursion safely without SIGSEGV
+        res = lib.PyErr_GivenExceptionMatches(TypeError(), tup)
+        self.assertEqual(res, 0)
+        if lib.PyErr_Occurred():
+            lib.PyErr_Clear()
+
 
 class PEP626Tests(unittest.TestCase):
 
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
new file mode 100644
index 000000000000000..9c8d1efbd761a00
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
@@ -0,0 +1,3 @@
+Fix unhandled recursion in :c:func:`PyErr_GivenExceptionMatches` when
+evaluating deeply nested exception tuples, preventing crashes caused by
+stack exhaustion.
diff --git a/Python/errors.c b/Python/errors.c
index 48b03e5fd714b18..6f16107c2385f84 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -335,16 +335,21 @@ PyErr_GivenExceptionMatches(PyObject *err, PyObject *exc)
         return 0;
     }
     if (PyTuple_Check(exc)) {
+        if (Py_EnterRecursiveCall(" in PyErr_GivenExceptionMatches")) {
+            return 0;
+        }
         Py_ssize_t i, n;
-        n = PyTuple_Size(exc);
+        n = PyTuple_GET_SIZE(exc);
         for (i = 0; i < n; i++) {
             /* Test recursively */
-             if (PyErr_GivenExceptionMatches(
-                 err, PyTuple_GET_ITEM(exc, i)))
-             {
-                 return 1;
-             }
+            if (PyErr_GivenExceptionMatches(
+                err, PyTuple_GET_ITEM(exc, i)))
+            {
+                Py_LeaveRecursiveCall();
+                return 1;
+            }
         }
+        Py_LeaveRecursiveCall();
         return 0;
     }
     /* err might be an instance, so check its class. */

From d0d85956659696e101e3c5d0645395ab197faee9 Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Fri, 21 Aug 2026 19:27:01 +0000
Subject: [PATCH 2/7] gh-156204: Safely skip ctypes test on mobile/wasm and
 reduce tuple depth

---
 Lib/test/test_exceptions.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 1aebdd5ba38fd5e..f77c02c442bc2c7 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -2778,8 +2778,11 @@ def test_except_star_invalid_exception_type(self):
             except (ValueError, 42):
                 pass
 
+    @cpython_only
+    @support.skip_emscripten_stack_overflow()
+    @support.skip_wasi_stack_overflow()
     def test_given_exception_matches_deeply_nested_tuple(self):
-        import ctypes
+        ctypes = import_module('ctypes')
         lib = ctypes.pythonapi
         lib.PyErr_GivenExceptionMatches.argtypes = [ctypes.py_object, ctypes.py_object]
         lib.PyErr_GivenExceptionMatches.restype = ctypes.c_int

From b6be6c5d9015c774bc82cadf63e2901894f3d54e Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Fri, 21 Aug 2026 20:16:21 +0000
Subject: [PATCH 3/7] gh-156204: address review feedback

---
 Doc/c-api/exceptions.rst                      |  7 ++++
 Lib/test/test_exceptions.py                   | 33 +++++++++++--------
 ...-08-21-18-49-12.gh-issue-156204.ZusA7e.rst |  2 +-
 Modules/_testcapi/exceptions.c                | 19 +++++++++++
 Python/errors.c                               | 16 ++++-----
 5 files changed, 53 insertions(+), 24 deletions(-)

diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst
index 40522f8c7b13756..a4d450424594ba0 100644
--- a/Doc/c-api/exceptions.rst
+++ b/Doc/c-api/exceptions.rst
@@ -486,6 +486,13 @@ Querying the error indicator
    of a subclass.  If *exc* is a tuple, all exception types in the tuple (and
    recursively in subtuples) are searched for a match.
 
+   If the subtuples are nested deeply enough to risk exhausting the C stack,
+   the search is abandoned, a :exc:`RecursionError` is set, and the function
+   returns false.
+
+   .. versionchanged:: next
+      Deeply nested subtuples previously crashed the interpreter.
+
 
 .. c:function:: PyObject *PyErr_GetRaisedException(void)
 
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index f77c02c442bc2c7..923e0ff9ec6dc84 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -2779,23 +2779,28 @@ def test_except_star_invalid_exception_type(self):
                 pass
 
     @cpython_only
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
+    def test_given_exception_matches_nested_tuple(self):
+        # Nested tuples are searched recursively.
+        self.assertTrue(
+            _testcapi.err_givenexceptionmatches(ValueError(), ((ValueError,),)))
+        self.assertFalse(
+            _testcapi.err_givenexceptionmatches(TypeError(), ((ValueError,),)))
+
+    @cpython_only
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     @support.skip_emscripten_stack_overflow()
     @support.skip_wasi_stack_overflow()
+    @support.run_with_limited_c_stack(depth=500_000)
     def test_given_exception_matches_deeply_nested_tuple(self):
-        ctypes = import_module('ctypes')
-        lib = ctypes.pythonapi
-        lib.PyErr_GivenExceptionMatches.argtypes = [ctypes.py_object, ctypes.py_object]
-        lib.PyErr_GivenExceptionMatches.restype = ctypes.c_int
-
-        tup = (1, ValueError)
-        for _ in range(50_000):
-            tup = (1, tup)
-
-        # PyErr_GivenExceptionMatches should handle deep recursion safely without SIGSEGV
-        res = lib.PyErr_GivenExceptionMatches(TypeError(), tup)
-        self.assertEqual(res, 0)
-        if lib.PyErr_Occurred():
-            lib.PyErr_Clear()
+        # gh-156204: PyErr_GivenExceptionMatches() used to exhaust the C stack
+        # and crash the interpreter on deeply nested tuples of exception types.
+        tup = (ValueError,)
+        for _ in range(500_000):
+            tup = (tup,)
+
+        with self.assertRaises(RecursionError):
+            _testcapi.err_givenexceptionmatches(TypeError(), tup)
 
 
 class PEP626Tests(unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
index 9c8d1efbd761a00..da40d41bc4115a6 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
@@ -1,3 +1,3 @@
-Fix unhandled recursion in :c:func:`PyErr_GivenExceptionMatches` when
+Fix unhandled recursion error in :c:func:`PyErr_GivenExceptionMatches` when
 evaluating deeply nested exception tuples, preventing crashes caused by
 stack exhaustion.
diff --git a/Modules/_testcapi/exceptions.c b/Modules/_testcapi/exceptions.c
index c0254e044bc2d5f..29a2dcf37fdffd7 100644
--- a/Modules/_testcapi/exceptions.c
+++ b/Modules/_testcapi/exceptions.c
@@ -54,6 +54,24 @@ err_restore(PyObject *self, PyObject *args) {
     return NULL;
 }
 
+static PyObject *
+err_givenexceptionmatches(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *err, *exc;
+    if (!PyArg_ParseTuple(args, "OO", &err, &exc)) {
+        return NULL;
+    }
+    assert(!PyErr_Occurred());
+    int res = PyErr_GivenExceptionMatches(err, exc);
+    /* PyErr_GivenExceptionMatches() has no failure return value, but it can
+     * set RecursionError on a deeply nested tuple; report that to the caller.
+     */
+    if (res == 0 && PyErr_Occurred()) {
+        return NULL;
+    }
+    return PyBool_FromLong(res);
+}
+
 /*[clinic input]
 _testcapi.exception_print
     exception as exc: object
@@ -544,6 +562,7 @@ static PyTypeObject PyRecursingInfinitelyError_Type = {
 
 static PyMethodDef test_methods[] = {
     {"err_restore",             err_restore,                     METH_VARARGS},
+    {"err_givenexceptionmatches", err_givenexceptionmatches,     METH_VARARGS},
     {"err_writeunraisable",     err_writeunraisable,             METH_VARARGS},
     {"err_formatunraisable",    err_formatunraisable,            METH_VARARGS},
     _TESTCAPI_ERR_SET_RAISED_METHODDEF
diff --git a/Python/errors.c b/Python/errors.c
index 6f16107c2385f84..2455fb07688d79c 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -338,19 +338,17 @@ PyErr_GivenExceptionMatches(PyObject *err, PyObject *exc)
         if (Py_EnterRecursiveCall(" in PyErr_GivenExceptionMatches")) {
             return 0;
         }
-        Py_ssize_t i, n;
-        n = PyTuple_GET_SIZE(exc);
-        for (i = 0; i < n; i++) {
+        int res = 0;
+        Py_ssize_t n = PyTuple_GET_SIZE(exc);
+        for (Py_ssize_t i = 0; i < n; i++) {
             /* Test recursively */
-            if (PyErr_GivenExceptionMatches(
-                err, PyTuple_GET_ITEM(exc, i)))
-            {
-                Py_LeaveRecursiveCall();
-                return 1;
+            if (PyErr_GivenExceptionMatches(err, PyTuple_GET_ITEM(exc, i))) {
+                res = 1;
+                break;
             }
         }
         Py_LeaveRecursiveCall();
-        return 0;
+        return res;
     }
     /* err might be an instance, so check its class. */
     if (PyExceptionInstance_Check(err))

From 170d3c961eaf6fa7193ef697b78e2a0479871982 Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Fri, 21 Aug 2026 20:28:44 +0000
Subject: [PATCH 4/7] gh-156204: drop docs change

---
 Doc/c-api/exceptions.rst | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst
index a4d450424594ba0..40522f8c7b13756 100644
--- a/Doc/c-api/exceptions.rst
+++ b/Doc/c-api/exceptions.rst
@@ -486,13 +486,6 @@ Querying the error indicator
    of a subclass.  If *exc* is a tuple, all exception types in the tuple (and
    recursively in subtuples) are searched for a match.
 
-   If the subtuples are nested deeply enough to risk exhausting the C stack,
-   the search is abandoned, a :exc:`RecursionError` is set, and the function
-   returns false.
-
-   .. versionchanged:: next
-      Deeply nested subtuples previously crashed the interpreter.
-
 
 .. c:function:: PyObject *PyErr_GetRaisedException(void)
 

From 12ce58fd9bf59b29a3eee285f2bf7d074d9f777d Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Thu, 24 Sep 2026 14:08:22 +0000
Subject: [PATCH 5/7] gh-156204: convert test helper to Argument Clinic

---
 Modules/_testcapi/clinic/exceptions.c.h | 33 ++++++++++++++++++++++++-
 Modules/_testcapi/exceptions.c          | 23 ++++++++++-------
 2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/Modules/_testcapi/clinic/exceptions.c.h b/Modules/_testcapi/clinic/exceptions.c.h
index cac5d288f437b72..89b78923bdb2d0c 100644
--- a/Modules/_testcapi/clinic/exceptions.c.h
+++ b/Modules/_testcapi/clinic/exceptions.c.h
@@ -16,6 +16,37 @@ PyDoc_STRVAR(_testcapi_err_set_raised__doc__,
 #define _TESTCAPI_ERR_SET_RAISED_METHODDEF    \
     {"err_set_raised", (PyCFunction)_testcapi_err_set_raised, METH_O, _testcapi_err_set_raised__doc__},
 
+PyDoc_STRVAR(_testcapi_err_givenexceptionmatches__doc__,
+"err_givenexceptionmatches($module, err, exc, /)\n"
+"--\n"
+"\n"
+"Test PyErr_GivenExceptionMatches().");
+
+#define _TESTCAPI_ERR_GIVENEXCEPTIONMATCHES_METHODDEF    \
+    {"err_givenexceptionmatches", _PyCFunction_CAST(_testcapi_err_givenexceptionmatches), METH_FASTCALL, _testcapi_err_givenexceptionmatches__doc__},
+
+static PyObject *
+_testcapi_err_givenexceptionmatches_impl(PyObject *module, PyObject *err,
+                                         PyObject *exc);
+
+static PyObject *
+_testcapi_err_givenexceptionmatches(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *return_value = NULL;
+    PyObject *err;
+    PyObject *exc;
+
+    if (!_PyArg_CheckPositional("err_givenexceptionmatches", nargs, 2, 2)) {
+        goto exit;
+    }
+    err = args[0];
+    exc = args[1];
+    return_value = _testcapi_err_givenexceptionmatches_impl(module, err, exc);
+
+exit:
+    return return_value;
+}
+
 PyDoc_STRVAR(_testcapi_exception_print__doc__,
 "exception_print($module, exception, legacy=False, /)\n"
 "--\n"
@@ -459,4 +490,4 @@ _testcapi_unstable_exc_prep_reraise_star(PyObject *module, PyObject *const *args
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=357caea020348789 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=a21ce5554900dba1 input=a9049054013a1b77]*/
diff --git a/Modules/_testcapi/exceptions.c b/Modules/_testcapi/exceptions.c
index 29a2dcf37fdffd7..f80a9c53e681e4c 100644
--- a/Modules/_testcapi/exceptions.c
+++ b/Modules/_testcapi/exceptions.c
@@ -54,18 +54,23 @@ err_restore(PyObject *self, PyObject *args) {
     return NULL;
 }
 
+/*[clinic input]
+_testcapi.err_givenexceptionmatches
+    err: object
+    exc: object
+    /
+
+Test PyErr_GivenExceptionMatches().
+[clinic start generated code]*/
+
 static PyObject *
-err_givenexceptionmatches(PyObject *Py_UNUSED(module), PyObject *args)
+_testcapi_err_givenexceptionmatches_impl(PyObject *module, PyObject *err,
+                                         PyObject *exc)
+/*[clinic end generated code: output=e40994ab6dd75001 input=7b8ef542df07575b]*/
 {
-    PyObject *err, *exc;
-    if (!PyArg_ParseTuple(args, "OO", &err, &exc)) {
-        return NULL;
-    }
     assert(!PyErr_Occurred());
     int res = PyErr_GivenExceptionMatches(err, exc);
-    /* PyErr_GivenExceptionMatches() has no failure return value, but it can
-     * set RecursionError on a deeply nested tuple; report that to the caller.
-     */
+    /* The function has no failure return, but it can set RecursionError. */
     if (res == 0 && PyErr_Occurred()) {
         return NULL;
     }
@@ -562,7 +567,6 @@ static PyTypeObject PyRecursingInfinitelyError_Type = {
 
 static PyMethodDef test_methods[] = {
     {"err_restore",             err_restore,                     METH_VARARGS},
-    {"err_givenexceptionmatches", err_givenexceptionmatches,     METH_VARARGS},
     {"err_writeunraisable",     err_writeunraisable,             METH_VARARGS},
     {"err_formatunraisable",    err_formatunraisable,            METH_VARARGS},
     _TESTCAPI_ERR_SET_RAISED_METHODDEF
@@ -571,6 +575,7 @@ static PyMethodDef test_methods[] = {
     _TESTCAPI_MAKE_EXCEPTION_WITH_DOC_METHODDEF
     _TESTCAPI_EXC_SET_OBJECT_METHODDEF
     _TESTCAPI_EXC_SET_OBJECT_FETCH_METHODDEF
+    _TESTCAPI_ERR_GIVENEXCEPTIONMATCHES_METHODDEF
     _TESTCAPI_ERR_SETSTRING_METHODDEF
     _TESTCAPI_ERR_SETFROMERRNOWITHFILENAME_METHODDEF
     _TESTCAPI_RAISE_EXCEPTION_METHODDEF

From e7c80b9cbc2b4187de6e5b5c90a89583dbce159f Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Thu, 24 Sep 2026 17:01:19 +0000
Subject: [PATCH 6/7] gh-156204: remove comment

---
 Modules/_testcapi/exceptions.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Modules/_testcapi/exceptions.c b/Modules/_testcapi/exceptions.c
index f80a9c53e681e4c..8c233e64ec3a354 100644
--- a/Modules/_testcapi/exceptions.c
+++ b/Modules/_testcapi/exceptions.c
@@ -70,7 +70,6 @@ _testcapi_err_givenexceptionmatches_impl(PyObject *module, PyObject *err,
 {
     assert(!PyErr_Occurred());
     int res = PyErr_GivenExceptionMatches(err, exc);
-    /* The function has no failure return, but it can set RecursionError. */
     if (res == 0 && PyErr_Occurred()) {
         return NULL;
     }

From 141b18193ba4e7aa54ce6a290da4a52eb451c2ed Mon Sep 17 00:00:00 2001
From: Bhuvansh Kataria <bhuvanshkataria@gmail.com>
Date: Sun, 27 Sep 2026 18:26:41 +0000
Subject: [PATCH 7/7] gh-156204: report recursion overflow as unraisable

---
 Lib/test/test_exceptions.py                          |  6 ++++--
 .../2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst   |  6 +++---
 Modules/_testcapi/exceptions.c                       |  4 +---
 Python/errors.c                                      | 12 ++++++++++--
 4 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index c3a655554361f92..963da1b0eae27ce 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -2827,8 +2827,10 @@ def test_given_exception_matches_deeply_nested_tuple(self):
         for _ in range(500_000):
             tup = (tup,)
 
-        with self.assertRaises(RecursionError):
-            _testcapi.err_givenexceptionmatches(TypeError(), tup)
+        with support.catch_unraisable_exception() as cm:
+            self.assertFalse(
+                _testcapi.err_givenexceptionmatches(ValueError(), tup))
+            self.assertIsInstance(cm.unraisable.exc_value, RecursionError)
 
 
 class PEP626Tests(unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
index da40d41bc4115a6..fade87c2d09ae1b 100644
--- a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-21-18-49-12.gh-issue-156204.ZusA7e.rst
@@ -1,3 +1,3 @@
-Fix unhandled recursion error in :c:func:`PyErr_GivenExceptionMatches` when
-evaluating deeply nested exception tuples, preventing crashes caused by
-stack exhaustion.
+Fix a crash in :c:func:`PyErr_GivenExceptionMatches` when evaluating deeply
+nested exception tuples. The recursion is now bounded, and exceeding the
+limit is reported as an unraisable exception.
diff --git a/Modules/_testcapi/exceptions.c b/Modules/_testcapi/exceptions.c
index 8c233e64ec3a354..cc62b47c99414a0 100644
--- a/Modules/_testcapi/exceptions.c
+++ b/Modules/_testcapi/exceptions.c
@@ -70,9 +70,7 @@ _testcapi_err_givenexceptionmatches_impl(PyObject *module, PyObject *err,
 {
     assert(!PyErr_Occurred());
     int res = PyErr_GivenExceptionMatches(err, exc);
-    if (res == 0 && PyErr_Occurred()) {
-        return NULL;
-    }
+    assert(!PyErr_Occurred());
     return PyBool_FromLong(res);
 }
 
diff --git a/Python/errors.c b/Python/errors.c
index 09e8d8f6832087a..edb1557e23f63bc 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -4,6 +4,7 @@
 #include "Python.h"
 #include "pycore_audit.h"         // _PySys_Audit()
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
+#include "pycore_ceval.h"         // _Py_ReachedRecursionLimitWithMargin()
 #include "pycore_fileutils.h"     // _PyFile_Flush
 #include "pycore_initconfig.h"    // _PyStatus_ERR()
 #include "pycore_pyerrors.h"      // _PyErr_Format()
@@ -337,7 +338,15 @@ PyErr_GivenExceptionMatches(PyObject *err, PyObject *exc)
         return 0;
     }
     if (PyTuple_Check(exc)) {
-        if (Py_EnterRecursiveCall(" in PyErr_GivenExceptionMatches")) {
+        PyThreadState *tstate = _PyThreadState_GET();
+        if (_Py_ReachedRecursionLimitWithMargin(tstate, 2)) {
+            PyObject *exc_value = _PyErr_GetRaisedException(tstate);
+            _PyErr_SetString(tstate, PyExc_RecursionError,
+                             "maximum recursion depth exceeded while "
+                             "checking exception tuple");
+            PyErr_FormatUnraisable("Exception ignored while "
+                                   "checking exception tuple");
+            _PyErr_SetRaisedException(tstate, exc_value);
             return 0;
         }
         int res = 0;
@@ -349,7 +358,6 @@ PyErr_GivenExceptionMatches(PyObject *err, PyObject *exc)
                 break;
             }
         }
-        Py_LeaveRecursiveCall();
         return res;
     }
     /* err might be an instance, so check its class. */