gh-76763: Make chr() always raising ValueError for out-of-range values (GH-114882)

Previously it raised OverflowError for very large or very small values.

Author: serhiy-storchaka

Lib/test/test_builtin.py

@@ -308,14 +308,13 @@ class C3(C2): pass
         self.assertTrue(callable(c3))
 
     def test_chr(self):
+        self.assertEqual(chr(0), '\0')
         self.assertEqual(chr(32), ' ')
         self.assertEqual(chr(65), 'A')
         self.assertEqual(chr(97), 'a')
         self.assertEqual(chr(0xff), '\xff')
-        self.assertRaises(ValueError, chr, 1<<24)
-        self.assertEqual(chr(sys.maxunicode),
-                         str('\\U0010ffff'.encode("ascii"), 'unicode-escape'))
         self.assertRaises(TypeError, chr)
+        self.assertRaises(TypeError, chr, 65.0)
         self.assertEqual(chr(0x0000FFFF), "\U0000FFFF")
         self.assertEqual(chr(0x00010000), "\U00010000")
         self.assertEqual(chr(0x00010001), "\U00010001")
@@ -327,7 +326,11 @@ def test_chr(self):
         self.assertEqual(chr(0x0010FFFF), "\U0010FFFF")
         self.assertRaises(ValueError, chr, -1)
         self.assertRaises(ValueError, chr, 0x00110000)
-        self.assertRaises((OverflowError, ValueError), chr, 2**32)
+        self.assertRaises(ValueError, chr, 1<<24)
+        self.assertRaises(ValueError, chr, 2**32-1)
+        self.assertRaises(ValueError, chr, -2**32)
+        self.assertRaises(ValueError, chr, 2**1000)
+        self.assertRaises(ValueError, chr, -2**1000)
 
     def test_cmp(self):
         self.assertTrue(not hasattr(builtins, "cmp"))

Misc/NEWS.d/next/Core and Builtins/2024-02-01-23-43-49.gh-issue-76763.o_2J6i.rst

@@ -0,0 +1,3 @@
+The :func:`chr` builtin function now always raises :exc:`ValueError` for
+values outside the valid range. Previously it raised :exc:`OverflowError` for
+very large or small values.

Python/bltinmodule.c

@@ -703,17 +703,34 @@ builtin_format_impl(PyObject *module, PyObject *value, PyObject *format_spec)
 /*[clinic input]
 chr as builtin_chr
 
-    i: int
+    i: object
     /
 
 Return a Unicode string of one character with ordinal i; 0 <= i <= 0x10ffff.
 [clinic start generated code]*/
 
 static PyObject *
-builtin_chr_impl(PyObject *module, int i)
-/*[clinic end generated code: output=c733afcd200afcb7 input=3f604ef45a70750d]*/
+builtin_chr(PyObject *module, PyObject *i)
+/*[clinic end generated code: output=d34f25b8035a9b10 input=f919867f0ba2f496]*/
 {
-    return PyUnicode_FromOrdinal(i);
+    int overflow;
+    long v = PyLong_AsLongAndOverflow(i, &overflow);
+    if (v == -1 && PyErr_Occurred()) {
+        return NULL;
+    }
+    if (overflow) {
+        v = overflow < 0 ? INT_MIN : INT_MAX;
+        /* Allow PyUnicode_FromOrdinal() to raise an exception */
+    }
+#if SIZEOF_INT < SIZEOF_LONG
+    else if (v < INT_MIN) {
+        v = INT_MIN;
+    }
+    else if (v > INT_MAX) {
+        v = INT_MAX;
+    }
+#endif
+    return PyUnicode_FromOrdinal(v);
 }