changeset:   93478:ec1948191461
branch:      3.4
parent:      93473:33908f14c0eb
user:        Benjamin Peterson <benjamin@python.org>
date:        Wed Nov 12 10:19:46 2014 -0500
files:       Lib/test/test_io.py Misc/NEWS Modules/_io/textio.c
description:
fix possible double free in TextIOWrapper.__init__ (closes #22849)


diff -r 33908f14c0eb -r ec1948191461 Lib/test/test_io.py
--- a/Lib/test/test_io.py	Tue Nov 11 11:01:09 2014 -0500
+++ b/Lib/test/test_io.py	Wed Nov 12 10:19:46 2014 -0500
@@ -2784,6 +2784,21 @@
         self.assertFalse(err)
         self.assertEqual("ok", out.decode().strip())
 
+    def test_issue22849(self):
+        class F(object):
+            def readable(self): return True
+            def writable(self): return True
+            def seekable(self): return True
+
+        for i in range(10):
+            try:
+                self.TextIOWrapper(F(), encoding='utf-8')
+            except Exception:
+                pass
+
+        F.tell = lambda x: 0
+        t = self.TextIOWrapper(F(), encoding='utf-8')
+
 
 class CTextIOWrapperTest(TextIOWrapperTest):
     io = io
diff -r 33908f14c0eb -r ec1948191461 Misc/NEWS
--- a/Misc/NEWS	Tue Nov 11 11:01:09 2014 -0500
+++ b/Misc/NEWS	Wed Nov 12 10:19:46 2014 -0500
@@ -36,6 +36,8 @@
 Library
 -------
 
+- Issue #22849: Fix possible double free in the io.TextIOWrapper constructor.
+
 - Issue #12728: Different Unicode characters having the same uppercase but
   different lowercase are now matched in case-insensitive regular expressions.
 
diff -r 33908f14c0eb -r ec1948191461 Modules/_io/textio.c
--- a/Modules/_io/textio.c	Tue Nov 11 11:01:09 2014 -0500
+++ b/Modules/_io/textio.c	Wed Nov 12 10:19:46 2014 -0500
@@ -1061,7 +1061,7 @@
     }
 
     /* Finished sorting out the codec details */
-    Py_DECREF(codec_info);
+    Py_CLEAR(codec_info);
 
     self->buffer = buffer;
     Py_INCREF(buffer);