[Zope] Important Fix for Zope 2.0 through 2.1.6

[Evan Simpson]

From: "Hannu Krosing" <hannu@tm.ee>
> Could something similar be happening in PCGIServer too ?
>
> We are getting some weird and hard-to-reproduce errors when activity
> goes up and several file uploads are going on simultaneously?

I'm not sure.  I've peeked at the code, and the exact same bug doesn't seem
to be at work.

One way to tell is to create two File objects, open their Upload tab in
side-by-side browser windows, choose the same long file (>1MB is good) in
both windows, then start the uploads together (as close as you can manage).

Next, change one of the windows into a Folder add form (any form will do,
really).  Now start the large file upload, then quickly submit the add form.

If there is a similar bug in PCGIServer, the first experiment will give you
a corrupted File (wrong size) and a weird log entry, and the second should
kill a thread with an "AttributeError:data" log entry.

Cheers,

Evan @ digicool & 4-am