pythongh-101037: Fix memory allocation for zeros of int subtypes

mdickinson · Jan 14, 2023 · ee51432 · ee51432
1 parent ef633e5
commit ee51432
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diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-01-14-17-03-08.gh-issue-101037.9ATNuf.rst b/Misc/NEWS.d/next/Core and Builtins/2023-01-14-17-03-08.gh-issue-101037.9ATNuf.rst
@@ -0,0 +1,2 @@
+Fix potential memory underallocation issue for instances of :class:`int`
+subclasses with value zero.
diff --git a/Objects/longobject.c b/Objects/longobject.c
@@ -5638,6 +5638,11 @@ long_subtype_new(PyTypeObject *type, PyObject *x, PyObject *obase)
     n = Py_SIZE(tmp);
     if (n < 0)
         n = -n;
+    /* Fast operations for single digit integers (including zero)
+     * assume that there is always at least one digit present. */
+    if (n == 0) {
+        n = 1;
+    }
     newobj = (PyLongObject *)type->tp_alloc(type, n);
     if (newobj == NULL) {
         Py_DECREF(tmp);
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Fix potential memory underallocation issue for instances of :class:`int`
		subclasses with value zero.