bpo-1617161: Make the hash and equality of methods not depending on the value of self. (GH-7848)

* The hash of BuiltinMethodType instances no longer depends on the hash
  of __self__. It depends now on the hash of id(__self__).
* The hash and equality of ModuleType and MethodWrapperType instances no
  longer depend on the hash and equality of __self__. They depend now on
  the hash and equality of id(__self__).
* MethodWrapperType instances no longer support ordering.

1 files changed, 1 insertions, 9 deletions

diff --git a/Objects/methodobject.c b/Objects/methodobject.c
index 9606768a48..a7042ca39e 100644
--- a/Objects/methodobject.c
+++ b/Objects/methodobject.c
@@ -251,16 +251,8 @@ static Py_hash_t
 meth_hash(PyCFunctionObject *a)
 {
     Py_hash_t x, y;
-    if (a->m_self == NULL)
-        x = 0;
-    else {
-        x = PyObject_Hash(a->m_self);
-        if (x == -1)
-            return -1;
-    }
+    x = _Py_HashPointer(a->m_self);
     y = _Py_HashPointer((void*)(a->m_ml->ml_meth));
-    if (y == -1)
-        return -1;
     x ^= y;
     if (x == -1)
         x = -2;