Index: Objects/floatobject.c
===================================================================
--- Objects/floatobject.c	(revision 86843)
+++ Objects/floatobject.c	(working copy)
@@ -176,21 +176,18 @@
     const char *s, *last, *end;
     double x;
     char buffer[256]; /* for errors */
-    char *s_buffer = NULL;
+    PyObject *s_buffer = NULL;
     Py_ssize_t len;
     PyObject *result = NULL;
 
     if (PyUnicode_Check(v)) {
-        s_buffer = (char *)PyMem_MALLOC(PyUnicode_GET_SIZE(v)+1);
+        s_buffer = PyUnicode_EncodeUTF8(PyUnicode_AS_UNICODE(v),
+                                        PyUnicode_GET_SIZE(v),
+                                        NULL);
         if (s_buffer == NULL)
-            return PyErr_NoMemory();
-        if (PyUnicode_EncodeDecimal(PyUnicode_AS_UNICODE(v),
-                                    PyUnicode_GET_SIZE(v),
-                                    s_buffer,
-                                    NULL))
-            goto error;
-        s = s_buffer;
-        len = strlen(s);
+            return NULL;
+        s = PyBytes_AS_STRING(s_buffer);
+        len = PyBytes_GET_SIZE(s_buffer);
     }
     else if (PyObject_AsCharBuffer(v, &s, &len)) {
         PyErr_SetString(PyExc_TypeError,
@@ -219,8 +216,7 @@
     }
 
   error:
-    if (s_buffer)
-        PyMem_FREE(s_buffer);
+    Py_XDECREF(s_buffer);
     return result;
 }