[3.15] gh-153210: Fix array module import crash under a memory pressure (GH-153238) (#153249)

gh-153210: Fix `array` module import crash under a memory pressure (GH-153238)
(cherry picked from commit 12ed8b1)

Co-authored-by: sobolevn <mail@sobolevn.me>

Author: miss-islington

Lib/test/test_array.py

@@ -5,7 +5,7 @@
 import collections.abc
 import unittest
 from test import support
-from test.support import import_helper
+from test.support import import_helper, script_helper
 from test.support import os_helper
 from test.support import _2G
 from test.support import subTests
@@ -49,6 +49,23 @@ def test_bad_constructor(self):
         self.assertRaises(ValueError, array.array, 'x')
         self.assertRaises(ValueError, array.array, 'Z')
 
+    @support.cpython_only
+    def test_does_not_crash_on_broken_imports(self):
+        # gh-153210
+        code = """if 1:
+            import collections.abc
+
+            del collections.abc.MutableSequence
+
+            try:
+                import array  # it used to crash before
+            except AttributeError:
+                pass
+            else:
+                raise AssertionError('AttributeError was not raised')
+        """
+        script_helper.assert_python_ok('-c', code)
+
     @support.cpython_only
     def test_disallow_instantiation(self):
         my_array = array.array("I")

Misc/NEWS.d/next/Library/2026-07-07-02-26-43.gh-issue-153210.LUXIcm.rst

@@ -0,0 +1 @@
+Fix crash on :mod:`array` import under a memory pressure.

Modules/arraymodule.c

@@ -3502,22 +3502,15 @@ array_modexec(PyObject *m)
     CREATE_TYPE(m, state->ArrayIterType, &arrayiter_spec);
     Py_SET_TYPE(state->ArrayIterType, &PyType_Type);
 
-    if (PyModule_AddObjectRef(m, "ArrayType",
-                              (PyObject *)state->ArrayType) < 0) {
-        return -1;
-    }
-
     PyObject *mutablesequence = PyImport_ImportModuleAttrString(
             "collections.abc", "MutableSequence");
     if (!mutablesequence) {
-        Py_DECREF((PyObject *)state->ArrayType);
         return -1;
     }
     PyObject *res = PyObject_CallMethod(mutablesequence, "register", "O",
                                         (PyObject *)state->ArrayType);
     Py_DECREF(mutablesequence);
     if (!res) {
-        Py_DECREF((PyObject *)state->ArrayType);
         return -1;
     }
     Py_DECREF(res);