fix: use _get_buffer_or_str in update() for consistent str error

update() now raises 'Strings must be encoded before hashing' for str
input, matching hashlib exactly and consistent with one-shot functions
and constructors.

Author: ifduyue

src/_xxhash.c

@@ -578,11 +578,13 @@ PyDoc_STRVAR(
 static PyObject *PYXXH32_update(PYXXH32Object *self, PyObject *arg)
 {
     Py_buffer buf;
+    PyObject *buf_owner;
 
-    if (PyObject_GetBuffer(arg, &buf, PyBUF_SIMPLE) < 0)
+    if (_get_buffer_or_str(arg, &buf, &buf_owner) < 0)
         return NULL;
 
     PYXXH32_do_update(self, &buf);
+    Py_XDECREF(buf_owner);
 
     Py_RETURN_NONE;
 }
@@ -931,11 +933,13 @@ PyDoc_STRVAR(
 static PyObject *PYXXH64_update(PYXXH64Object *self, PyObject *arg)
 {
     Py_buffer buf;
+    PyObject *buf_owner;
 
-    if (PyObject_GetBuffer(arg, &buf, PyBUF_SIMPLE) < 0)
+    if (_get_buffer_or_str(arg, &buf, &buf_owner) < 0)
         return NULL;
 
     PYXXH64_do_update(self, &buf);
+    Py_XDECREF(buf_owner);
 
     Py_RETURN_NONE;
 }
@@ -1283,11 +1287,13 @@ PyDoc_STRVAR(
 static PyObject *PYXXH3_64_update(PYXXH3_64Object *self, PyObject *arg)
 {
     Py_buffer buf;
+    PyObject *buf_owner;
 
-    if (PyObject_GetBuffer(arg, &buf, PyBUF_SIMPLE) < 0)
+    if (_get_buffer_or_str(arg, &buf, &buf_owner) < 0)
         return NULL;
 
     PYXXH3_64_do_update(self, &buf);
+    Py_XDECREF(buf_owner);
 
     Py_RETURN_NONE;
 }
@@ -1644,11 +1650,13 @@ PyDoc_STRVAR(
 static PyObject *PYXXH3_128_update(PYXXH3_128Object *self, PyObject *arg)
 {
     Py_buffer buf;
+    PyObject *buf_owner;
 
-    if (PyObject_GetBuffer(arg, &buf, PyBUF_SIMPLE) < 0)
+    if (_get_buffer_or_str(arg, &buf, &buf_owner) < 0)
         return NULL;
 
     PYXXH3_128_do_update(self, &buf);
+    Py_XDECREF(buf_owner);
 
     Py_RETURN_NONE;
 }

tests/test_hashlib_compat.py

@@ -35,7 +35,8 @@ def test_str_rejected_constructor(self):
     def test_str_rejected_update(self):
         for algo in ('xxh32', 'xxh64', 'xxh3_64', 'xxh3_128'):
             obj = getattr(xxhash, algo)()
-            with self.assertRaises(TypeError):
+            with self.assertRaisesRegex(TypeError,
+                    'Strings must be encoded before hashing'):
                 obj.update('hello')
 
     # ── data keyword ───────────────────────────────────────────────