Fix decimal and docs as well

Author: rhettinger

Doc/library/stdtypes.rst

@@ -692,10 +692,9 @@ Here are the rules in detail:
   as ``-hash(-x)``.  If the resulting hash is ``-1``, replace it with
   ``-2``.
 
-- The particular values ``sys.hash_info.inf``, ``-sys.hash_info.inf``
-  and ``sys.hash_info.nan`` are used as hash values for positive
-  infinity, negative infinity, or nans (respectively).  (All hashable
-  nans have the same hash value.)
+- The particular values ``sys.hash_info.inf`` and ``-sys.hash_info.inf``
+  are used as hash values for positive
+  infinity or negative infinity (respectively).
 
 - For a :class:`complex` number ``z``, the hash values of the real
   and imaginary parts are combined by computing ``hash(z.real) +
@@ -740,7 +739,7 @@ number, :class:`float`, or :class:`complex`::
        """Compute the hash of a float x."""
 
        if math.isnan(x):
-           return sys.hash_info.nan
+           return id(x)
        elif math.isinf(x):
            return sys.hash_info.inf if x > 0 else -sys.hash_info.inf
        else:

Lib/_pydecimal.py

@@ -951,7 +951,7 @@ def __hash__(self):
             if self.is_snan():
                 raise TypeError('Cannot hash a signaling NaN value.')
             elif self.is_nan():
-                return _PyHASH_NAN
+                return id(self)
             else:
                 if self._sign:
                     return -_PyHASH_INF

Modules/_decimal/_decimal.c

@@ -4536,7 +4536,6 @@ _dec_hash(PyDecObject *v)
     #error "No valid combination of CONFIG_64, CONFIG_32 and _PyHASH_BITS"
 #endif
     const Py_hash_t py_hash_inf = 314159;
-    const Py_hash_t py_hash_nan = 0;
     mpd_uint_t ten_data[1] = {10};
     mpd_t ten = {MPD_POS|MPD_STATIC|MPD_CONST_DATA,
                  0, 2, 1, 1, ten_data};
@@ -4555,7 +4554,7 @@ _dec_hash(PyDecObject *v)
             return -1;
         }
         else if (mpd_isnan(MPD(v))) {
-            return py_hash_nan;
+            return (Py_hash_t) v;
         }
         else {
             return py_hash_inf * mpd_arith_sign(MPD(v));