From 5a44424c5e6b9533b12773fadeaf436903ca855e Mon Sep 17 00:00:00 2001
From: Georg Brandl <georg@python.org>
Date: Fri, 21 Mar 2008 20:11:46 +0000
Subject: [PATCH] #2358: add py3k warning to sys.exc_clear().

---
 Lib/test/test_py3kwarn.py |  5 +++++
 Misc/NEWS                 |  2 ++
 Python/sysmodule.c        | 10 +++++++++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_py3kwarn.py b/Lib/test/test_py3kwarn.py
index 2b54ee1cf4b..aaa16231b94 100644
--- a/Lib/test/test_py3kwarn.py
+++ b/Lib/test/test_py3kwarn.py
@@ -94,6 +94,11 @@ class TestPy3KWarnings(unittest.TestCase):
         with catch_warning() as w:
             self.assertWarning(sorted(lst, cmp), w, expected)
 
+    def test_sys_exc_clear(self):
+        expected = 'sys.exc_clear() not supported in 3.x. Use except clauses.'
+        with catch_warning() as w:
+            self.assertWarning(sys.exc_clear(), w, expected)
+
 def test_main():
     run_unittest(TestPy3KWarnings)
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 70409364ec8..a581247a0a8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -11,6 +11,8 @@ What's New in Python 2.6 alpha 2?
 
 Core and builtins
 -----------------
+ 
+- Issue #2358: Add a Py3k warning on sys.exc_clear() usage.
 
 - Issue #2400: Allow relative imports to "import *".
 
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 8e27844eaa2..385969f8e2b 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -169,8 +169,16 @@ clause in the current stack frame or in an older stack frame."
 static PyObject *
 sys_exc_clear(PyObject *self, PyObject *noargs)
 {
-	PyThreadState *tstate = PyThreadState_GET();
+	PyThreadState *tstate;
 	PyObject *tmp_type, *tmp_value, *tmp_tb;
+
+	if (Py_Py3kWarningFlag &&
+	    PyErr_Warn(PyExc_DeprecationWarning,
+		       "sys.exc_clear() not supported in 3.x. "
+		       "Use except clauses.") < 0)
+		return NULL;
+
+	tstate = PyThreadState_GET();
 	tmp_type = tstate->exc_type;
 	tmp_value = tstate->exc_value;
 	tmp_tb = tstate->exc_traceback;