diff -r 16c4137a413c Lib/test/test_format.py
--- a/Lib/test/test_format.py	Wed Oct 05 22:34:51 2011 +0200
+++ b/Lib/test/test_format.py	Wed Nov 16 00:46:07 2011 +0100
@@ -289,6 +289,17 @@
             else:
                 raise TestFailed, '"%*d"%(maxsize, -127) should fail'
 
+    def test_issue13410(self):
+        class Foo(object):
+            def __init__(self, x):
+                self.x = x
+            def __long__(self):
+                return long(self.x)
+            def __float__(self):
+                return float(self.x)
+        print '%d' % Foo(22)
+        
+
 def test_main():
     test_support.run_unittest(FormatTest)
 
diff -r 16c4137a413c Objects/stringobject.c
--- a/Objects/stringobject.c	Wed Oct 05 22:34:51 2011 +0200
+++ b/Objects/stringobject.c	Wed Nov 16 00:46:07 2011 +0100
@@ -4476,7 +4476,10 @@
                     }
                     else {
                         iobj = PyNumber_Int(v);
-                        if (iobj==NULL) iobj = PyNumber_Long(v);
+                        if (iobj==NULL) {
+                            PyErr_Clear();
+                            iobj = PyNumber_Long(v);
+                        }
                     }
                     if (iobj!=NULL) {
                         if (PyInt_Check(iobj)) {