fix: raise hashlib-compatible error for None input

Add Py_None check in _get_buffer_or_str to raise:
  TypeError: object supporting the buffer API required
matching hashlib.md5(None) exactly. Tests updated to verify.

Author: ifduyue

src/_xxhash.c

@@ -54,6 +54,11 @@
 static Py_ALWAYS_INLINE int
 _get_buffer_or_str(PyObject *obj, Py_buffer *buf)
 {
+    if (obj == Py_None) {
+        PyErr_SetString(PyExc_TypeError,
+            "object supporting the buffer API required");
+        return -1;
+    }
     if (PyUnicode_Check(obj)) {
         PyErr_SetString(PyExc_TypeError,
             "Strings must be encoded before hashing");

tests/test_hashlib_compat.py

@@ -32,7 +32,8 @@ def test_str_rejected(self):
                         'Strings must be encoded before hashing'):
                     fn(data='hello')
                 # None
-                with self.assertRaises(TypeError):
+                with self.assertRaisesRegex(TypeError,
+                        'object supporting the buffer API required'):
                     fn(None)
 
     def test_str_rejected_constructor(self):
@@ -47,9 +48,11 @@ def test_str_rejected_constructor(self):
                     'Strings must be encoded before hashing'):
                 cls(data='hello')
             # None
-            with self.assertRaises(TypeError):
+            with self.assertRaisesRegex(TypeError,
+                    'object supporting the buffer API required'):
                 cls(None)
-            with self.assertRaises(TypeError):
+            with self.assertRaisesRegex(TypeError,
+                    'object supporting the buffer API required'):
                 cls(data=None)
 
     def test_str_rejected_update(self):
@@ -62,7 +65,8 @@ def test_str_rejected_update(self):
             obj.update(b'hello')
             self.assertIsInstance(obj.intdigest(), int)
             # None
-            with self.assertRaises(TypeError):
+            with self.assertRaisesRegex(TypeError,
+                    'object supporting the buffer API required'):
                 obj.update(None)
 
     # ── data keyword ───────────────────────────────────────────────

xxhash/version.py

@@ -1,3 +1,3 @@
-VERSION = "3.8.0.dev4"
+VERSION = "3.8.0.dev6"
 #: Deprecated, will be removed in the next major release
 VERSION_TUPLE = (3, 8, 0)