Stop producing or using OverflowWarning.  PEP 237 thought this would
happen in 2.3, but nobody noticed it still was getting generated (the
warning was disabled by default).  OverflowWarning and
PyExc_OverflowWarning should be removed for 2.5, and left notes all over
saying so.
diff --git a/Objects/intobject.c b/Objects/intobject.c
index f52ef07..763ed53 100644
--- a/Objects/intobject.c
+++ b/Objects/intobject.c
@@ -10,19 +10,6 @@
 	return LONG_MAX;	/* To initialize sys.maxint */
 }
 
-/* Return 1 if exception raised, 0 if caller should retry using longs */
-static int
-err_ovf(char *msg)
-{
-	if (PyErr_Warn(PyExc_OverflowWarning, msg) < 0) {
-		if (PyErr_ExceptionMatches(PyExc_OverflowWarning))
-			PyErr_SetString(PyExc_OverflowError, msg);
-		return 1;
-	}
-	else
-		return 0;
-}
-
 /* Integers are quite normal objects, to make object handling uniform.
    (Using odd pointers to represent integers would save much space
    but require extra checks for this special case throughout the code.)
@@ -306,11 +293,8 @@
 		PyErr_SetString(PyExc_ValueError, buffer);
 		return NULL;
 	}
-	else if (errno != 0) {
-		if (err_ovf("string/unicode conversion"))
-			return NULL;
+	else if (errno != 0)
 		return PyLong_FromString(s, pend, base);
-	}
 	if (pend)
 		*pend = end;
 	return PyInt_FromLong(x);
@@ -396,8 +380,6 @@
 	x = a + b;
 	if ((x^a) >= 0 || (x^b) >= 0)
 		return PyInt_FromLong(x);
-	if (err_ovf("integer addition"))
-		return NULL;
 	return PyLong_Type.tp_as_number->nb_add((PyObject *)v, (PyObject *)w);
 }
 
@@ -410,8 +392,6 @@
 	x = a - b;
 	if ((x^a) >= 0 || (x^~b) >= 0)
 		return PyInt_FromLong(x);
-	if (err_ovf("integer subtraction"))
-		return NULL;
 	return PyLong_Type.tp_as_number->nb_subtract((PyObject *)v,
 						     (PyObject *)w);
 }
@@ -475,8 +455,6 @@
 		   32 * absdiff <= absprod -- 5 good bits is "close enough" */
 		if (32.0 * absdiff <= absprod)
 			return PyInt_FromLong(longprod);
-		else if (err_ovf("integer multiplication"))
-			return NULL;
 		else
 			return PyLong_Type.tp_as_number->nb_multiply(v, w);
 	}
@@ -501,11 +479,8 @@
 		return DIVMOD_ERROR;
 	}
 	/* (-sys.maxint-1)/-1 is the only overflow case. */
-	if (y == -1 && x < 0 && x == -x) {
-		if (err_ovf("integer division"))
-			return DIVMOD_ERROR;
+	if (y == -1 && x < 0 && x == -x)
 		return DIVMOD_OVERFLOW;
-	}
 	xdivy = x / y;
 	xmody = x - xdivy * y;
 	/* If the signs of x and y differ, and the remainder is non-0,
@@ -654,8 +629,6 @@
 			if (temp == 0)
 				break; /* Avoid ix / 0 */
 			if (ix / temp != prev) {
-				if (err_ovf("integer exponentiation"))
-					return NULL;
 				return PyLong_Type.tp_as_number->nb_power(
 					(PyObject *)v,
 					(PyObject *)w,
@@ -666,9 +639,7 @@
 	        if (iw==0) break;
 	 	prev = temp;
 	 	temp *= temp;	/* Square the value of temp */
-	 	if (prev!=0 && temp/prev!=prev) {
-			if (err_ovf("integer exponentiation"))
-				return NULL;
+	 	if (prev != 0 && temp / prev != prev) {
 			return PyLong_Type.tp_as_number->nb_power(
 				(PyObject *)v, (PyObject *)w, (PyObject *)z);
 		}
@@ -701,10 +672,7 @@
 	a = v->ob_ival;
 	x = -a;
 	if (a < 0 && x < 0) {
-		PyObject *o;
-		if (err_ovf("integer negation"))
-			return NULL;
-		o = PyLong_FromLong(a);
+		PyObject *o = PyLong_FromLong(a);
 		if (o != NULL) {
 			PyObject *result = PyNumber_Negative(o);
 			Py_DECREF(o);