From 0fbab7ff8d2efd92e222fcc13c0aff0998c3c158 Mon Sep 17 00:00:00 2001
From: Christian Heimes <christian@cheimes.de>
Date: Tue, 4 Dec 2007 21:55:18 +0000
Subject: [PATCH] Removed another occurrence of PyInt_ExactCheck() I've
 modified the semantic of PyTraceBack_Print and sys.tracebacklimit slightly.
 Overfloats or values <= 0 are replaced with a default value to avoid infinite
 recursion and other issues.

---
 Python/traceback.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/Python/traceback.c b/Python/traceback.c
index df2a3a302eb..1a4ec1fd58c 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -242,12 +242,15 @@ tb_printinternal(PyTracebackObject *tb, PyObject *f, int limit)
 	return err;
 }
 
+#define PyTraceBack_LIMIT 1000
+
 int
 PyTraceBack_Print(PyObject *v, PyObject *f)
 {
 	int err;
 	PyObject *limitv;
-	int limit = 1000;
+	int limit = PyTraceBack_LIMIT;
+
 	if (v == NULL)
 		return 0;
 	if (!PyTraceBack_Check(v)) {
@@ -255,10 +258,26 @@ PyTraceBack_Print(PyObject *v, PyObject *f)
 		return -1;
 	}
 	limitv = PySys_GetObject("tracebacklimit");
-	if (limitv && PyInt_CheckExact(limitv)) {
+	if (limitv) {
+		PyObject *exc_type, *exc_value, *exc_tb;
+
+		PyErr_Fetch(&exc_type, &exc_value, &exc_tb);
 		limit = PyLong_AsLong(limitv);
-		if (limit <= 0)
-			return 0;
+		if (limit == -1 && PyErr_Occurred()) {
+			if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
+				limit = PyTraceBack_LIMIT;
+			}
+			else {
+				Py_XDECREF(exc_type);
+				Py_XDECREF(exc_value);
+				Py_XDECREF(exc_tb);
+				return 0;
+			}
+		}
+		else if (limit <= 0) {
+			limit = PyTraceBack_LIMIT;
+		}
+		PyErr_Restore(exc_type, exc_value, exc_tb);
 	}
 	err = PyFile_WriteString("Traceback (most recent call last):\n", f);
 	if (!err)