bpo-31993: Do not use memoryview when pickle large strings. (#5154)

PyMemoryView_FromMemory() created a memoryview referring to
the internal data of the string.  When the string is destroyed
the memoryview become referring to a freed memory.

1 files changed, 3 insertions, 2 deletions

diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 5b3de4d..f8cbea1 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -2184,8 +2184,9 @@ _Pickler_write_bytes(PicklerObject *self,
         /* Stream write the payload into the file without going through the
            output buffer. */
         if (payload == NULL) {
-            payload = mem = PyMemoryView_FromMemory((char *) data, data_size,
-                                                    PyBUF_READ);
+            /* TODO: It would be better to use a memoryview with a linked
+               original string if this is possible. */
+            payload = mem = PyBytes_FromStringAndSize(data, data_size);
             if (payload == NULL) {
                 return -1;
             }