1 files changed, 57 insertions, 48 deletions

diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index d92bec35b5f..da600f4aa82 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -215,35 +215,49 @@ double
 PyFloat_AsDouble(PyObject *op)
 {
     PyNumberMethods *nb;
-    PyFloatObject *fo;
+    PyObject *res;
     double val;
 
-    if (op && PyFloat_Check(op))
-        return PyFloat_AS_DOUBLE((PyFloatObject*) op);
-
     if (op == NULL) {
         PyErr_BadArgument();
         return -1;
     }
 
-    if ((nb = Py_TYPE(op)->tp_as_number) == NULL || nb->nb_float == NULL) {
-        PyErr_SetString(PyExc_TypeError, "a float is required");
-        return -1;
+    if (PyFloat_Check(op)) {
+        return PyFloat_AS_DOUBLE(op);
     }
 
-    fo = (PyFloatObject*) (*nb->nb_float) (op);
-    if (fo == NULL)
-        return -1;
-    if (!PyFloat_Check(fo)) {
-        Py_DECREF(fo);
-        PyErr_SetString(PyExc_TypeError,
-                        "nb_float should return float object");
+    nb = Py_TYPE(op)->tp_as_number;
+    if (nb == NULL || nb->nb_float == NULL) {
+        PyErr_Format(PyExc_TypeError, "must be real number, not %.50s",
+                     op->ob_type->tp_name);
         return -1;
     }
 
-    val = PyFloat_AS_DOUBLE(fo);
-    Py_DECREF(fo);
+    res = (*nb->nb_float) (op);
+    if (res == NULL) {
+        return -1;
+    }
+    if (!PyFloat_CheckExact(res)) {
+        if (!PyFloat_Check(res)) {
+            PyErr_Format(PyExc_TypeError,
+                         "%.50s.__float__ returned non-float (type %.50s)",
+                         op->ob_type->tp_name, res->ob_type->tp_name);
+            Py_DECREF(res);
+            return -1;
+        }
+        if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1,
+                "%.50s.__float__ returned non-float (type %.50s).  "
+                "The ability to return an instance of a strict subclass of float "
+                "is deprecated, and may be removed in a future version of Python.",
+                op->ob_type->tp_name, res->ob_type->tp_name)) {
+            Py_DECREF(res);
+            return -1;
+        }
+    }
 
+    val = PyFloat_AS_DOUBLE(res);
+    Py_DECREF(res);
     return val;
 }
 
@@ -1195,7 +1209,7 @@ Return a hexadecimal representation of a floating-point number.\n\
 static PyObject *
 float_fromhex(PyObject *cls, PyObject *arg)
 {
-    PyObject *result_as_float, *result;
+    PyObject *result;
     double x;
     long exp, top_exp, lsb, key_digit;
     char *s, *coeff_start, *s_store, *coeff_end, *exp_start, *s_end;
@@ -1410,11 +1424,10 @@ float_fromhex(PyObject *cls, PyObject *arg)
         s++;
     if (s != s_end)
         goto parse_error;
-    result_as_float = Py_BuildValue("(d)", negate ? -x : x);
-    if (result_as_float == NULL)
-        return NULL;
-    result = PyObject_CallObject(cls, result_as_float);
-    Py_DECREF(result_as_float);
+    result = PyFloat_FromDouble(negate ? -x : x);
+    if (cls != (PyObject *)&PyFloat_Type && result != NULL) {
+        Py_SETREF(result, PyObject_CallFunctionObjArgs(cls, result, NULL));
+    }
     return result;
 
   overflow_error:
@@ -1451,29 +1464,23 @@ float_as_integer_ratio(PyObject *v, PyObject *unused)
     int exponent;
     int i;
 
-    PyObject *prev;
     PyObject *py_exponent = NULL;
     PyObject *numerator = NULL;
     PyObject *denominator = NULL;
     PyObject *result_pair = NULL;
     PyNumberMethods *long_methods = PyLong_Type.tp_as_number;
 
-#define INPLACE_UPDATE(obj, call) \
-    prev = obj; \
-    obj = call; \
-    Py_DECREF(prev); \
-
     CONVERT_TO_DOUBLE(v, self);
 
     if (Py_IS_INFINITY(self)) {
-      PyErr_SetString(PyExc_OverflowError,
-                      "Cannot pass infinity to float.as_integer_ratio.");
-      return NULL;
+        PyErr_SetString(PyExc_OverflowError,
+                        "cannot convert Infinity to integer ratio");
+        return NULL;
     }
     if (Py_IS_NAN(self)) {
-      PyErr_SetString(PyExc_ValueError,
-                      "Cannot pass NaN to float.as_integer_ratio.");
-      return NULL;
+        PyErr_SetString(PyExc_ValueError,
+                        "cannot convert NaN to integer ratio");
+        return NULL;
     }
 
     PyFPE_START_PROTECT("as_integer_ratio", goto error);
@@ -1489,29 +1496,31 @@ float_as_integer_ratio(PyObject *v, PyObject *unused)
        to be truncated by PyLong_FromDouble(). */
 
     numerator = PyLong_FromDouble(float_part);
-    if (numerator == NULL) goto error;
+    if (numerator == NULL)
+        goto error;
+    denominator = PyLong_FromLong(1);
+    if (denominator == NULL)
+        goto error;
+    py_exponent = PyLong_FromLong(Py_ABS(exponent));
+    if (py_exponent == NULL)
+        goto error;
 
     /* fold in 2**exponent */
-    denominator = PyLong_FromLong(1);
-    py_exponent = PyLong_FromLong(labs((long)exponent));
-    if (py_exponent == NULL) goto error;
-    INPLACE_UPDATE(py_exponent,
-                   long_methods->nb_lshift(denominator, py_exponent));
-    if (py_exponent == NULL) goto error;
     if (exponent > 0) {
-        INPLACE_UPDATE(numerator,
-                       long_methods->nb_multiply(numerator, py_exponent));
-        if (numerator == NULL) goto error;
+        Py_SETREF(numerator,
+                  long_methods->nb_lshift(numerator, py_exponent));
+        if (numerator == NULL)
+            goto error;
     }
     else {
-        Py_DECREF(denominator);
-        denominator = py_exponent;
-        py_exponent = NULL;
+        Py_SETREF(denominator,
+                  long_methods->nb_lshift(denominator, py_exponent));
+        if (denominator == NULL)
+            goto error;
     }
 
     result_pair = PyTuple_Pack(2, numerator, denominator);
 
-#undef INPLACE_UPDATE
 error:
     Py_XDECREF(py_exponent);
     Py_XDECREF(denominator);