gh-125889: Fix bounds check of hi argument in bisect_left|right functions

Lib/bisect.py

@@ -33,7 +33,7 @@ def bisect_right(a, x, lo=0, hi=None, *, key=None):
 
     if lo < 0:
         raise ValueError('lo must be non-negative')
-    if hi is None:
+    if hi is None or hi < 0:
         hi = len(a)
     # Note, the comparison uses "<" to match the
     # __lt__() logic in list.sort() and in heapq.
@@ -86,7 +86,7 @@ def bisect_left(a, x, lo=0, hi=None, *, key=None):
 
     if lo < 0:
         raise ValueError('lo must be non-negative')
-    if hi is None:
+    if hi is None or hi < 0:
         hi = len(a)
     # Note, the comparison uses "<" to match the
     # __lt__() logic in list.sort() and in heapq.

Lib/test/test_bisect.py

@@ -118,13 +118,18 @@ def test_precomputed(self):
             self.assertEqual(func(data, elem), expected)
             self.assertEqual(func(UserList(data), elem), expected)
 
-    def test_negative_lo(self):
+    def test_negative_hi_lo(self):
         # Issue 3301
         mod = self.module
         self.assertRaises(ValueError, mod.bisect_left, [1, 2, 3], 5, -1, 3)
         self.assertRaises(ValueError, mod.bisect_right, [1, 2, 3], 5, -1, 3)
         self.assertRaises(ValueError, mod.insort_left, [1, 2, 3], 5, -1, 3)
         self.assertRaises(ValueError, mod.insort_right, [1, 2, 3], 5, -1, 3)
+        # Test c implementation
+        self.assertRaises(ValueError, c_bisect.bisect_left, [1, 2, 3], 5, 3, -2)
+        self.assertRaises(ValueError, c_bisect.bisect_right, [1, 2, 3], 5, 3, -2)
+        self.assertRaises(ValueError, c_bisect.insort_left, [1, 2, 3], 5, 3, -2)
+        self.assertRaises(ValueError, c_bisect.insort_right, [1, 2, 3], 5, 3, -2)
 
     def test_large_range(self):
         # Issue 13496

Misc/NEWS.d/next/Library/2024-10-24-15-21-03.gh-issue-125889.P9MXpN.rst

@@ -0,0 +1 @@
+Allow negative values ​​for ``hi`` argument of ``bisect_left/right`` and ``insort_left/right``.

Modules/_bisectmodule.c

@@ -66,6 +66,10 @@ internal_bisect_right(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t
         if (hi < 0)
             return -1;
     }
+    if (hi < 0) {
+        PyErr_SetString(PyExc_ValueError, "hi must be non-negative");
+        return -1;
+    }
     ssizeargfunc sq_item = get_sq_item(list);
     if (sq_item == NULL) {
         return -1;
@@ -250,6 +254,10 @@ internal_bisect_left(PyObject *list, PyObject *item, Py_ssize_t lo, Py_ssize_t h
         if (hi < 0)
             return -1;
     }
+    if (hi < 0) {
+        PyErr_SetString(PyExc_ValueError, "hi must be non-negative");
+        return -1;
+    }
     ssizeargfunc sq_item = get_sq_item(list);
     if (sq_item == NULL) {
         return -1;