Merged revisions 77352-77354 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r77352 | antoine.pitrou | 2010-01-07 18:46:49 +0100 (jeu., 07 janv. 2010) | 5 lines

  Issue #7455: Fix possible crash in cPickle on invalid input.  Patch by
  Florent Xicluna.
........
  r77353 | antoine.pitrou | 2010-01-07 18:49:37 +0100 (jeu., 07 janv. 2010) | 3 lines

  Fix attribution. Florent actually repackaged and reviewed Victor's patch (sorry!).
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  r77354 | antoine.pitrou | 2010-01-07 18:54:10 +0100 (jeu., 07 janv. 2010) | 3 lines

  Fix reattribution mistake when fixing attribution mistake!
........

Lib/test/pickletester.py

@@ -1139,6 +1139,9 @@ def test_bad_input(self):
         # Test issue4298
         s = bytes([0x58, 0, 0, 0, 0x54])
         self.assertRaises(EOFError, pickle.loads, s)
+        # Test issue7455
+        s = b'0'
+        self.assertRaises(pickle.UnpicklingError, pickle.loads, s)
 
 
 class AbstractPersistentPicklerTests(unittest.TestCase):

Misc/NEWS

@@ -194,6 +194,9 @@ C-API
 Library
 -------
 
+- Issue #7455: Fix possible crash in cPickle on invalid input.  Patch by
+  Victor Stinner.
+
 - Issue #1628205: Socket file objects returned by socket.socket.makefile() now
   properly handles EINTR within the read, readline, write & flush methods.
   The socket.sendall() method now properly handles interrupted system calls.

Modules/_pickle.c

@@ -3729,7 +3729,7 @@ load_pop(UnpicklerObject *self)
      */
     if (self->num_marks > 0 && self->marks[self->num_marks - 1] == len) {
         self->num_marks--;
-    } else if (len >= 0) {
+    } else if (len > 0) {
         len--;
         Py_DECREF(self->stack->data[len]);
         self->stack->length = len;