Merged revisions 88022 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r88022 | antoine.pitrou | 2011-01-15 17:17:07 +0100 (sam., 15 janv. 2011) | 7 lines

  Issue #10916: mmap should not segfault when a file is mapped using 0 as
  length and a non-zero offset, and an attempt to read past the end of file
  is made (IndexError is raised instead).  Patch by Ross Lagerwall.

  Requested by Georg.
........
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index d6d1601..6ca95c9 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -1164,7 +1164,7 @@
 #  endif
     if (fd != -1 && fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) {
         if (map_size == 0) {
-            map_size = st.st_size;
+            map_size = st.st_size - offset;
         } else if ((size_t)offset + (size_t)map_size > st.st_size) {
             PyErr_SetString(PyExc_ValueError,
                             "mmap length is greater than file size");