Merged revisions 88131 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r88131 | antoine.pitrou | 2011-01-20 22:07:24 +0100 (jeu., 20 janv. 2011) | 6 lines

  Issue #10955: Fix a potential crash when trying to mmap() a file past its
  length.  Initial patch by Ross Lagerwall.

  This fixes a regression introduced by r88022.
........
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 20ec564..86dea1e 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -343,6 +343,19 @@
             finally:
                 mf.close()
 
+    def test_length_0_large_offset(self):
+        # Issue #10959: test mapping of a file by passing 0 for
+        # map length with a large offset doesn't cause a segfault.
+        if not hasattr(os, "stat"):
+            self.skipTest("needs os.stat")
+
+        with open(TESTFN, "wb") as f:
+            f.write(115699 * b'm') # Arbitrary character
+
+        with open(TESTFN, "w+b") as f:
+            self.assertRaises(ValueError, mmap.mmap, f.fileno(), 0,
+                              offset=2147418112)
+
     def test_move(self):
         # make move works everywhere (64-bit format problem earlier)
         f = open(TESTFN, 'w+')