[3.13] pythongh-135326: Restore support of __index__ in random.getrandbits() (python#135332)

Author: serhiy-storchaka

Lib/test/test_random.py

@@ -14,6 +14,15 @@
 from fractions import Fraction
 from collections import abc, Counter
 
+
+class MyIndex:
+    def __init__(self, value):
+        self.value = value
+
+    def __index__(self):
+        return self.value
+
+
 class TestBasicOps:
     # Superclass with tests common to all generators.
     # Subclasses must arrange for self.gen to retrieve the Random instance
@@ -393,7 +402,7 @@ def test_getrandbits(self):
         self.assertRaises(TypeError, self.gen.getrandbits, 1, 2)
         self.assertRaises(ValueError, self.gen.getrandbits, -1)
         self.assertRaises(OverflowError, self.gen.getrandbits, 1<<1000)
-        self.assertRaises(ValueError, self.gen.getrandbits, -1<<1000)
+        self.assertRaises((ValueError, OverflowError), self.gen.getrandbits, -1<<1000)
         self.assertRaises(TypeError, self.gen.getrandbits, 10.1)
 
     def test_pickling(self):
@@ -809,6 +818,9 @@ def test_getrandbits(self):
         self.gen.seed(1234567)
         self.assertEqual(self.gen.getrandbits(100),
                          97904845777343510404718956115)
+        self.gen.seed(1234567)
+        self.assertEqual(self.gen.getrandbits(MyIndex(100)),
+                         97904845777343510404718956115)
 
     def test_getrandbits_2G_bits(self):
         size = 2**31

Misc/NEWS.d/next/Library/2025-06-10-10-00-17.gh-issue-135326.sOHe_p.rst

@@ -0,0 +1,2 @@
+Restore support of integer-like objects with :meth:`!__index__` in
+:func:`random.getrandbits`.

Modules/_randommodule.c

@@ -495,21 +495,27 @@ _random_Random_setstate_impl(RandomObject *self, PyObject *state)
 _random.Random.getrandbits
 
   self: self(type="RandomObject *")
-  k: unsigned_long_long(bitwise=False)
+  k: long_long
   /
 
 getrandbits(k) -> x.  Generates an int with k random bits.
 [clinic start generated code]*/
 
 static PyObject *
-_random_Random_getrandbits_impl(RandomObject *self, unsigned long long k)
-/*[clinic end generated code: output=25a604fab95885d4 input=88e51091eea2f042]*/
+_random_Random_getrandbits_impl(RandomObject *self, long long k)
+/*[clinic end generated code: output=c2c02a7b0bfdf7f7 input=834d0fe668b981e4]*/
 {
     Py_ssize_t i, words;
     uint32_t r;
     uint32_t *wordarray;
     PyObject *result;
 
+    if (k < 0) {
+        PyErr_SetString(PyExc_ValueError,
+                        "number of bits must be non-negative");
+        return NULL;
+    }
+
     if (k == 0)
         return PyLong_FromLong(0);