gh-142029: Raise ValueError instead of crashing on empty name given to create_builtin() (#142033)

Co-authored-by: Victor Stinner <[email protected]>

Author: dr-carlos

Lib/test/test_import/__init__.py

@@ -1253,6 +1253,20 @@ class Spec2:
                 origin = "a\x00b"
             _imp.create_dynamic(Spec2())
 
+    def test_create_builtin(self):
+        class Spec:
+            name = None
+        spec = Spec()
+
+        with self.assertRaisesRegex(TypeError, 'name must be string, not NoneType'):
+            _imp.create_builtin(spec)
+
+        spec.name = ""
+
+        # gh-142029
+        with self.assertRaisesRegex(ValueError, 'name must not be empty'):
+            _imp.create_builtin(spec)
+
     def test_filter_syntax_warnings_by_module(self):
         module_re = r'test\.test_import\.data\.syntax_warnings\z'
         unload('test.test_import.data.syntax_warnings')

Misc/NEWS.d/next/Core_and_Builtins/2025-11-28-16-45-07.gh-issue-142029.JuXiKu.rst

@@ -0,0 +1,2 @@
+Raise :exc:`ValueError` instead of crashing when empty string is used as a name
+in ``_imp.create_builtin()``.

Python/import.c

@@ -4420,6 +4420,12 @@ _imp_create_builtin(PyObject *module, PyObject *spec)
         return NULL;
     }
 
+    if (PyUnicode_GetLength(name) == 0) {
+        PyErr_Format(PyExc_ValueError, "name must not be empty");
+        Py_DECREF(name);
+        return NULL;
+    }
+
     PyObject *mod = create_builtin(tstate, name, spec, NULL);
     Py_DECREF(name);
     return mod;