explicitly fix memoryview.hex

Author: picnixz

Lib/test/test_memoryview.py

@@ -4,7 +4,6 @@
    are in test_buffer.
 """
 
-import contextlib
 import unittest
 import test.support
 import sys
@@ -455,9 +454,7 @@ def __len__(self):
                 ba.clear()
                 return 1
 
-        # The following should not crash but it may not necessarily raise.
-        with contextlib.suppress(BufferError):
-            mv.hex(S(b':'))
+        self.assertRaises(BufferError, mv.hex, S(b':'))
 
 
 # Variations on source objects for the buffer: bytes-like objects, then arrays

Objects/memoryobject.c

@@ -2349,7 +2349,10 @@ memoryview_hex_impl(PyMemoryViewObject *self, PyObject *sep,
     CHECK_RELEASED(self);
 
     if (MV_C_CONTIGUOUS(self->flags)) {
-        return _Py_strhex_with_sep(src->buf, src->len, sep, bytes_per_sep);
+        self->exports++;
+        PyObject *ret = _Py_strhex_with_sep(src->buf, src->len, sep, bytes_per_sep);
+        self->exports--;
+        return ret;
     }
 
     PyBytesWriter *writer = PyBytesWriter_Create(src->len);