Fix SF bug# 676155, RuntimeWarning with tp_compare

Check return value of PyLong_AsDouble(), it can return an error.
diff --git a/Misc/NEWS b/Misc/NEWS
index 971cfe0..028c21b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -23,6 +23,10 @@
 - Fixed crash when printing a subclass of str and __str__ returned self.
   See SF bug #667147.
 
+- Fixed an invalid RuntimeWarning and an undetected error when trying
+  to convert a long integer into a float which couldn't fit.  
+  See SF bug #676155.
+
 Extension modules
 -----------------