Created an mmap for a file in update mode, seek to end of file, and
invoke write_byte. The file is not updated (as expected), but did not
get any error indicating the write was out of bounds, and when I invoke
tell(), it reports a position that is out of bounds. I check size(), and
it still reports the correct size (less than the value reported by
tell()). If I do seek(0, os.SEEK_END), it correctly returns to the end
of the map, instead of this bizarre no-mans land beyond the end.

This is on Windows XP.

Here's an example from the shell. (note that write() works as I would
expect, it raises an exception and doesn't modify the position):

>>> map.tell()
0
>>> map.size()
8
>>> map.seek(0, os.SEEK_END)
>>> map.tell()
8
>>> map.write("foo")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: data out of range
>>> map.tell()
8
>>> map.size()
8
>>> map.write_byte('x')
>>> map.tell()
9
>>> map.size()
8
>>> print "WTF?"
WTF?
>>> map.write_byte('x')
>>> map.tell()
10
>>> map.size()
8
>>> map.flush()
1
>>> map.size()
8
>>> map.tell()
10
>>> map.seek(0, os.SEEK_END)
>>> map.tell()
8
>>> map.size()
8
>>>

Can you try this with Python2.6.2? I believe this bug got fixed.

Confirmed fixed in python 2.6.2

Thank you for response. I'll close this entry.

On Wed, May 6, 2009 at 8:51 AM, Hirokazu Yamamoto
<report@bugs.python.org> wrote:
>
> Hirokazu Yamamoto <ocean-city@m2.ccsnet.ne.jp> added the comment:
>
> Thank you for response. I'll close this entry.
>
> ----------
> resolution:  -> out of date
> status: open -> closed
>

Ok, thanks. I wasn't sure if I should close it or not.